Page 1 of 97 DRAFT Didecyl Dimethyl Ammonium Chloride ( DDAC)

Occupational and Residential Exposure Assessment ( DP Barcode 323309)

Office of Pesticide Programs Antimicrobials Division U. S. Environmental Protection Agency 1801 South Bell St. Arlington, VA 22202 Date: April 18, 2006 Page 2 of 97 TABLE OF CONTENTS EXECUTIVE SUMMARY............................................................................................................................................ 3 1.0 INTRODUCTION.......................................................................................................................................... 9 1.1 Purpose........................................................................................................................................................ 9 1.2 Criteria for Conducting Exposure Assessments ......................................................................................... 9 1.3 Chemical Identification ............................................................................................................................. 11 1.4 Physical/ Chemical Properties ................................................................................................................... 12 2.0 USE INFORMATION.................................................................................................................................. 12 2.1 Formulation Types and Percent Active Ingredient .................................................................................. 12 2.2 Summary of Use Pattern and Formulations ............................................................................................. 12 3.0 SUMMARY OF TOXICITY DATA............................................................................................................ 13 3.1 Acute Toxicity........................................................................................................................................... 13 3.2 Summary of Toxicity Endpoints................................................................................................................ 13 3.3 FQPA Considerations ............................................................................................................................... 15 4.0 RESIDENTIAL EXPOSURE ASSESSMENT ............................................................................................ 15 4.1 Summary of Registered Uses .................................................................................................................... 15 4.2 Residential Exposure................................................................................................................................. 15 4.2.1 Residential Handler Exposures ....................................................................................................... 17 4.2.2 Residential Post application Exposures.......................................................................................... 20 4.2.3 Data Limitations/ Uncertainties ....................................................................................................... 36 5.0 RESIDENTIAL AGGREGATE RISK ASSESSMENT AND CHARACTERIZATION........................... 37 6.0 OCCUPATIONAL EXPOSURE ASSESSMENT....................................................................................... 37 6.1 Occupational Handler Exposures ............................................................................................................. 40 6.2 Occupational Post application Exposures ................................................................................................ 44 6.3 Wood Preservation.................................................................................................................................... 47 6.3.1 Non Pressure Treatment Scenarios ( Handler and Post application) ............................................. 47 6.3.2 Pressure Treatment Scenarios ( Handler and Post Application)..................................................... 51 6.4 Data Limitations/ Uncertainties ................................................................................................................. 54 7.0 REFERENCES .............................................................................................................................................. 56 APPENDIX A: Master DDAC Label........................................................................................................................... 58 APPENDIX B: Summary of CMA and PHED Data.................................................................................................... 71 APPENDIX C: Input/ Output from Residential MCCEM Modeling............................................................................ 74 APPENDIX D: Input/ Output from Occupational MCCEM Modeling........................................................................ 86 APPENDIX E: Calculation of DDAC Unit Exposure Values .................................................................................... 95 Page 3 of 97 EXECUTIVE SUMMARY This document is the Occupational and Residential Exposure Chapter of the Reregistration Eligibility Decision ( RED) document for the Group I Quat Cluster. It addresses the potential risks to humans that result from the use of chemicals in this group in occupational and residential settings. Group I Quat Cluster is a group of structurally similar quaternary ammonium compounds (" quats") that are characterized by having a positively charged nitrogen covalently bonded to two alkyl group substituents ( at least one C8 or longer) and two methyl substituents. In finished form, these quats are salts with the positively charged nitrogen ( cation) balanced by a negatively charged molecule ( anion). The anion for the quats in this cluster is chloride or bromide. In this document, the Group I Quat Cluster will be referred to as DDAC ( didecyl dimethyl ammonium chloride).

DDAC is the active ingredient in numerous types of products. The products are mainly disinfectants and deodorants that are used in agricultural, food handling, commercial/ institutional/ industrial, residential and public access, and medical settings ( Use Site Categories I, II, III, IV, and V respectively). Examples of registered uses for DDAC in these settings include application to indoor and outdoor hard surfaces ( e. g., walls, floors, tables, toilets, and fixtures), eating utensils, laundry, carpets, agricultural tools and vehicles, egg shells, shoes, milking equipment and udders, humidifiers, medical instruments, human remains, ultrasonic tanks, reverse osmosis units, and water storage tanks. There are also DDAC containing products that are used in residential and commercial swimming pools ( Use Site Category XI), in aquatic areas ( Use Site Category XII) such as decorative ponds and decorative fountains, and in industrial process and water systems ( Use Site Category VIII) such as re circulating cooling water systems, drilling muds and packer fluids, oil well injection and wastewater systems. Additionally, DDAC containing products are used for wood preservation ( Use Site Category X) through non pressure and pressure treatment methods. There are registered uses for fogging in occupational settings. Products containing DDAC are formulated as liquid ready to use, soluble concentrate, pressurized liquid, and water soluble packaging. The percentage of DDAC in the various end use products ranges from 0.08% to 80% as reported in the Master Label spreadsheet ( Appendix A). Residential products such as EPA Reg. No. 10324 69 range up to 50% DDAC for swimming pools and spas.

The durations and routes of exposure evaluated in this assessment include short term ( ST), intermediate term ( IT), and in some instances long term ( LT) inhalation exposures, ST dermal exposures, and ST oral exposures. The ST inhalation endpoint and the ST oral endpoint is based on a NOAEL of 10 mg/ kg/ day from a prenatal developmental toxicity study in rats. The LOAEL ( 20 mg/ kg/ day) was based largely on increased incidence of skeletal variations in females. The developmental study does not indicate increased susceptibility from in utero and postnatal exposure to DDAC. The IT/ LT inhalation endpoint is also based on a 10 mg/ kg/ day but from a chronic toxicity study in dogs. No short term dermal endpoint for systemic effects was selected for DDAC, since no systemic effects were identified. However, a short term dermal irritation endpoint was identified. The short term dermal endpoint for the technical grade active ingredient ( TGAI) containing 80% ai diluted to 0.1% DDAC as a test material ( 2 mg/ kg/ day which is equivalent to 8 µ g/ cm2) was determined from a LOAEL of 6 mg/ kg/ day based on increased clinical and gross findings ( erythema, edema, exfoliation, excoriation, and ulceration). A 21 day dermal toxicity study was also conducted using a 0.13% ai formulation. No short term dermal endpoint was identified for this formulation Page 4 of 97 because no irritation or systemic effects were identified up to and including the limit dose of 1,000 mg/ kg/ day. Intermediate or long term dermal irritation endpoints were not identified for DDAC. Because the effect to the skin is a localized skin irritation, a skin concentration ( µ g/ cm2) of exposure, rather then a dose ( mg/ kg/ day) was used to assess the dermal risk concerns. No body weight is needed for the dermal irritation endpoint, since no systemic dose is calculated. Since the toxicological endpoint for inhalation is female specific, a body weight of 60 kilograms is used in the assessment. This represents the body weight of an adult female. They Agency's level of concern ( LOC) for occupational and residential DDAC dermal, inhalation and oral exposures is 100 ( i. e., a margin of exposure ( MOE) less than 100 exceeds the level of concern). The level of concern is based on 10x for interspecies extrapolation and 10x for intraspecies extrapolation.

The dermal and inhalation margins of exposure were not combined for the DDAC risk assessment because the toxicity endpoints for the dermal and inhalation routes of exposure are based on different toxicological effects. No cancer endpoint was identified; therefore, cancer risks are not assessed.

This occupational and residential assessment was based on examination of product labels describing uses for the product. There are many end use products that contain DDAC; therefore, only labels on the Master Label developed by AD and the registrants were reviewed. It has been determined that exposure to handlers can occur in a variety of occupational and residential environments. Additionally, post application exposures are likely to occur in these settings. The representative scenarios selected by the Antimicrobials Division ( AD) for assessment were evaluated using maximum application rates as stated on the product labels. The representative scenarios are believed to represent high end uses resulting in dermal, inhalation, and incidental oral exposures.

To assess most handler risks, AD used surrogate unit exposure data from the Chemical Manufacturers Association ( CMA) antimicrobial exposure study and the Pesticide Handlers Exposure Database ( PHED). Postapplication/ bystander exposures were assessed using EPA's Health Effects Division's ( HED) Standard Operating Procedures ( SOPs) for Residential Exposure Assessment, MCCEM ( Multi Chamber Concentration and Exposure Model), and Swim Model. Additionally, handler and post application exposures resulting from wood preservation activities were assessed using surrogate data from the studies Measurement and Assessment of Dermal and Inhalation Exposures to Didecyl Dimethyl Ammonium Chloride ( DDAC) Used in the Protection of Cut Lumber ( Phase III) ( Bestari et al., 1999, MRID 455243 04) and " Assessment of Potential Inhalation and Dermal Exposure Associated with Pressure Treatment of Wood with Arsenical Wood Products" ( ACC, 2002a). Residential Handler Risk Summary Dermal For the residential handler dermal exposure and risk assessment, dermal risks were calculated by comparing residues on the surface of the skin to the short term dermal irritation endpoints. Dermal residential handler exposures were not assessed for products containing less than 1% DDAC. Residues on the surface of the skin ( dermal irritation exposure) were determined using hand unit exposures from CMA and/ or PHED adjusted for the surface area of the hand ( mg/ lb ai/ cm2), application rates, and use amounts. The dermal Page 5 of 97 MOEs were below the target MOE of 100 for all scenarios except the humidifier and swimming pool applications.

Inhalation For the residential handler inhalation assessment, the inhalation risks were calculated by comparing the daily doses to the short term inhalation endpoint. The inhalation MOEs were above the target MOE of 100 for all scenarios.

Residential Post Application/ Bystander Risk Summary Dermal The residential post application dermal risks were assessed by comparing the surface residue on the skin ( dermal skin irritation exposure) to the short term dermal endpoint. It was assumed that during the exposure period the skin repeatedly contacts the treated surface until a steady state concentration of residues is achieved on the skin. For residential scenarios, the post application dermal MOEs were above the target MOE of 100 for the laundered clothing ( assuming 1% residue transfer) but below the target MOE for the following:

  Wearing clothes treated with a fabric spray: ST dermal MOE = less than or equal to 1 using both a 100% clothing to skin transfer factor and a 5% clothing to skin transfer factor.   Dermal contact on floors ( MOE = 33) and carpets ( MOE = 45).   There are no wipe data available to assess the children's dermal contact to treated decks and/ or play sets. Based on hand measurements of workers at the treatment plants, dermal risks may be of concern and therefore a wipe study is warranted.

Inhalation For the residential post application inhalation exposure and risk assessment, the MOEs were below the target MOE of 100 for the following scenario:

  Humidifier: ST/ IT 8 hr Inhalation MOE = 27 for adults and 8 for children; ST/ IT 24 hr Inhalation MOE = 11 for adults and 5 for children Incidental Oral For the residential post application incidental oral assessment, the MOEs were above the target MOE of 100 for all scenarios except the following:

  Mouthing on clothes treated with a fabric spray: ST oral MOE = 12 Occupational Handler Risk Summary Dermal DDAC dermal irritation exposures and risks were not estimated for occupational handler exposures. Instead, dermal irritation exposures and risks will be mitigated using default personal protective equipment requirements based on the toxicity of the end use product. To minimize dermal exposures, the minimum PPE required for mixers, loaders, and others exposed to end use products containing concentrations of DDAC that result in classification of category I, II, or III for skin irritation potential will be long sleeve shirt, long Page 6 of 97 pants, shoes, socks, chemical resistant gloves, and chemical resistant apron. Once diluted, if the concentration of DDAC in the diluted solution would result in classification of toxicity category IV for skin irritation potential, then the chemical resistant gloves and chemicalresistant apron can be eliminated for applicators and others exposed to the dilute. Note that chemical resistant eyewear will be required if the end use product is classified as category I or II for eye irritation potential.

Inhalation For the occupational handler inhalation exposure and risk assessment, the MOEs were above the target MOE of 100 for all scenarios.

A confirmatory inhalation toxicity study may be warranted because inhalation MOEs were below 1,000 for the following scenarios:

  Small process water systems, liquid pour: ST/ IT Inhalation MOE = 130   Agricultural fogging, mixing and loading: ST/ IT Inhalation MOE = 110   Medical premises, mopping: ST/ IT Inhalation MOE = 280   Wood Preservation ( non pressure treatment), blender/ sprayer: ST/ IT/ LT Inhalation MOE = 280 Occupational Post Application/ Bystander Risk Summary Dermal Dermal irritation exposures are assumed to be negligible for all post application occupational scenarios, except those associated with wood preservation. As with occupational handlers, dermal irritation exposures and risks from post application activities in a wood preservation treatment facility will be mitigated using default personal protective equipment requirements based on the toxicity of the end use product. For construction workers handling treated wood the MOEs are potentially of concern. A wipe study on treated wood will be needed to refine these potential exposures.

Inhalation For the occupational inhalation post application exposure and risk assessment, the MOEs were above the target MOE of 100 for all scenarios except for the following scenarios listed below.

  Fogging in a food processing plant: The 8 hr MOE from 2 to 10 hours ( 2 hour reentry interval) = 8.

A confirmatory inhalation toxicity study may be warranted because the inhalation MOE was below 1,000 ( additional 10x uncertainty factor is considered because of the lack of an inhalation route specific toxicological endpoint) for the following scenarios:

  Fogging in a hatchery: The 8 hr MOE from 0 to 8 hours ( entering immediately after fogging) = 120.   Non pressure treatment wood preservation, clean up worker: ST/ IT/ LT Inhalation MOE = 990 Page 7 of 97 Data Limitations and Uncertainties:

There are a number of uncertainties associated with this assessment and these have been reiterated from Sections 4.2.3 ( residential) and 6.4 ( occupational) respectively.

The data limitations and uncertainties associated with the residential handler and postapplication exposure assessments include the following:

  Surrogate dermal and inhalation unit exposure values were taken from the proprietary Chemical Manufacturers Association ( CMA) antimicrobial exposure study ( USEPA, 1999: DP Barcode D247642) or from the Pesticide Handler Exposure Database ( USEPA, 1998) ( See Appendix B for summaries of these data sources). Most of the CMA data are of poor quality therefore, AD requests that confirmatory monitoring data be generated to support the values used in these assessments.   The quantities handled/ treated were estimated based on information from various sources, including HED's Standard Operating Procedures ( SOPs) for Residential Exposure Assessments ( USEPA 2000 and 2001). In certain cases, no standard values were available for some scenarios. Assumptions for these scenarios were based on AD estimates and could be further refined from input from registrants.   Some labels for products which can be used by homeowners in residential settings, as well as by workers in occupational settings, indicate that low pressure sprayers can be used for application of the disinfectant to hard, non porous surfaces such as floors and walls. A low pressure spray scenario was not assessed for the residential scenario because it is not a typical cleaning method for homeowners.   In this assessment, incidental ingestion and dermal exposures to treated wood were estimated using DDAC data from an occupational exposure study. The degree of uncertainty ( under or overestimation) associated with using the DDAC hand residue data for dermal and oral exposure from contacting treated lumber are unknown. The amount of residue measured on the test subjects hands is variable and are influenced by the duration of exposure, how often wood is contacted, and the degree of contact ( i. e., do the hand residues from the DDAC study mimic a child's play activity on decks and playsets?). A wipe study on treated wood is needed to refine these estimates.   Available data to assess the levels of DDAC in soil contaminated with DDAC treated wood do not exist at this time. In addition, leaching data were also not available. Because of this data gap, EPA was not able to accurately predict dermal and incidental ingestion residential post application exposures to soil contaminated with DDAC treated wood.

The data limitations and uncertainties associated with the occupational handler and postapplication exposure assessments include:

  Surrogate dermal and inhalation unit exposure values were taken from the proprietary Chemical Manufacturers Association ( CMA) antimicrobial exposure study ( USEPA, 1999: DP Barcode D247642) or from the Pesticide Handler Exposure Database ( USEPA, 1998) ( See Appendix B for summaries of these data sources). Since the CMA data are of poor quality, the Agency requests that confirmatory data be submitted to support the occupational scenarios assessed in this document.   Unit exposures are not available for some of the specific scenarios that are prescribed for DDAC, including open loading into oil well/ field environments Page 8 of 97 o The CMA data used for oil well uses are based on open pouring of a material preservative. Although these data are only represented by 2 replicates each, the exposure values are similar to open loading of pesticides in PHED. Furthermore, there are no representative unit exposure data for chemical metering into secondary recovery oil operations. Since the volume of water being treated in secondary recovery operations is so large, the available CMA data can not be reliably extrapolated because they are based on activities that handle much lower volumes and possibly different techniques. Therefore, it was assumed that if the open pour handling activities for the other oil well operations resulted in MOEs that are not of concern, then the MOEs for the closed system chemical metering into secondary recovery operations would also be not of concern. AD requests that confirmatory data be conducted to show that this is accurate.   For the wood preservative pressure treatment scenarios, CCA exposure data were used for lack of DDAC specific exposure data. Limitations and uncertainties associated with the use of these data include: o The assumption was made that exposure patterns for workers at treatment facilities using CCA would be similar to exposure patterns for workers at treatment facilities using DDAC, and therefore the exposures could be used as surrogate data for workers that treat wood with DDAC. o For environmental modeling, it was assumed that the leaching process from the DDAC treated wood would be similar to that of CCA. However, due to the lack of real data for DDAC  treated wood, it is not possible to verify this assumption.   The quantities handled/ treated were estimated based on information from various sources, including HED's Standard Operating Procedures ( SOPs) for Residential Exposure Assessments ( USEPA 2000 and 2001) and personal communication with experts. In particular, the use information for oil well uses and cooling water tower uses are based on personal communication with biocide manufacturers for these types of uses. The individuals contacted have experience in these operations and their estimates are believed to be the best available without undertaking a statistical survey of the uses. In certain cases, no standard values were available for some scenarios. Assumptions for these scenarios were based on AD estimates and could be further refined from input from registrants.   The percent active ingredient in solution for the pressure treatment of lumber needs to be refined by the registrant. The labels only provided a retention rate. For this assessment, the application rate on the master label was used, which is the same as the application rate for non pressure treatment of lumber. Page 9 of 97 1.0 INTRODUCTION 1.1 Purpose In this document, the Antimicrobials Division ( AD) presents the results of its review of the potential human health effects of occupational and residential exposure to DDAC. This information is for use in EPA's development of the DDAC Reregistration Eligibility Decision ( RED) document.

1.2 Criteria for Conducting Exposure Assessments An occupational and/ or residential exposure assessment is required for an active ingredient if ( 1) certain toxicological criteria are triggered and ( 2) there is potential exposure to handlers ( mixers, loaders, applicators, etc.) during use or to persons entering treated sites after application is complete. For DDAC, both criteria are met. Toxicological endpoints were selected for short and intermediate term dermal, inhalation, and incidental oral exposures to DDAC. There is a significant potential for exposure in a variety of occupational and residential settings. Therefore, risk assessments are required for occupational and residential handlers as well as for occupational and residential postapplication exposures that can occur as a result of DDAC use.

In this document, handler scenarios were assessed by using unit exposure data to estimate occupational and residential handlers' exposures. Unit exposures are estimates of the amount of exposure to an active ingredient a handler receives while performing various handler tasks and are expressed in terms of micrograms or milligrams ( 1 mg = 1,000 µ g) of active ingredient per pounds of active ingredient handled. A series of unit exposures have been developed that are unique for each scenario typically considered in assessments ( i. e., there are different unit exposures for different types of application equipment, job functions, and levels of protection). The unit exposure concept has been established in the scientific literature and also through various exposure monitoring guidelines published by the USEPA and international organizations such as Health Canada and OECD ( Organization for Economic Cooperation and Development).

Using surrogate unit exposure data, maximum application rates from labels, and EPA estimates of daily amount handled, exposures and risks to handlers were assessed. The exposure/ risks were calculated using the following equations:

Daily Exposure: Daily dermal and inhalation handler exposures are estimated for each applicable handler task with the application rate, quantity treated/ handled in a day, and the applicable inhalation unit exposure using the following formula:

Daily Inhalation Exposure: E = UE x AR x AT ( Eq. 1a)

Where: E = Amount ( mg ai/ day) inhaled that is available for inhalation absorption; UE = Hand unit exposure value ( mg ai/ lb ai) derived from August 1998 PHED data or from 1992 CMA data; Page 10 of 97 AR = Maximum application rate based on a logical unit treatment, such as acres ( A), square feet ( sq. ft.), gallons ( gal), or cubic feet ( cu. ft). Maximum values are generally used ( lb ai/ A, lb ai/ sq ft, lb ai/ gal, lb ai/ cu ft); and AT = Normalized application area based on a logical unit treatment such as acres ( A/ day), square feet ( sq ft/ day), gallons ( gal/ day), or cubic feet ( cu. ft./ day).

Daily Dermal Skin Irritation Exposure: E = UEhand/ SAhand x AR x AT ( Eq. 1b)

Where: E = Amount ( mg ai/ cm2) deposited on the surface of the skin; UEhand = Unit exposure value ( mg ai/ lb ai) derived from August 1998 PHED data or from 1992 CMA data; SAhand = Surface area of two hands ( 820 cm2); AR = Maximum application rate based on a logical unit treatment, such as acres ( A), square feet ( sq. ft.), gallons ( gal), or cubic feet ( cu. ft). Maximum values are generally used ( lb ai/ A, lb ai/ sq ft, lb ai/ gal, lb ai/ cu ft); and AT = Normalized application area based on a logical unit treatment such as acres ( A/ day), square feet ( sq ft/ day), gallons ( gal/ day), or cubic feet ( cu. ft./ day).

Daily Dose: The inhalation dose is calculated by normalizing the daily exposure by body weight and adjusting, if necessary, with an appropriate absorption factor. An absorption factor of 100% was used for inhalation exposures. A daily dose is not calculated for dermal exposures, because the dermal endpoint selected is based on irritation effects, not systemic effects. Daily dose was calculated using the following formula:

Daily Dose: ADD = E x ABS ( Eq. 2) BW Where: ADD = Average daily dose or the absorbed dose received from exposure to a chemical in a given scenario ( mg active ingredient/ kg body weight/ day); E = Amount ( mg ai/ day) inhaled that is available for inhalation absorption; ABS = A measure of the amount of chemical that crosses a biological boundary such as lungs (% of the total available absorbed); and BW = Body weight determined to represent the population of interest in a risk assessment ( kg).

Margins of Exposure: Non cancer inhalation risks for each applicable handler scenario are calculated using a Margin of Exposure ( MOE). This is the ratio of the daily inhalation dose or dermal exposure to the toxicological endpoint of concern.

Margins of Exposure ( inhalation): MOE = NOAEL or LOAEL ( Eq. 3a) ADD Where: MOE = Margin of exposure, value used to represent risk or how close a chemical exposure is to being a concern ( unitless); NOAEL or LOAEL = Systemic toxicity level where no observed adverse effects ( NOAEL) or where the lowest observed adverse effects ( LOAEL) occurred in the study ( mg ai/ kg body weight/ day); and ADD = Average daily inhalation dose in a given scenario ( mg ai/ kg body weight/ day).

Margins of Exposure ( dermal): MOE = NOAEL or LOAEL ( Eq. 3b) E Page 11 of 97 Where: MOE = Margin of exposure, value used to represent risk or how close a chemical exposure is to being a concern ( unitless); NOAEL or LOAEL = Irritation toxicity level where no observed adverse effects ( NOAEL) or where the lowest observed adverse effects ( LOAEL) occurred in the study (: g/ cm2); and E = Dermal skin irritation exposure in a given scenario (: g/ cm2).

In addition to the target MOEs presented in Table 3.2 that were used for the analysis, a series of assumptions and exposure factors served as the basis for completing the handler risk assessment. Each general assumption and factor for both residential and occupational assessments is detailed below. Assumptions specific to the use site category are listed in each separate section of this document. The general assumptions and factors include:

  DDAC products are widely used and have a large number of use patterns that are difficult to completely capture in this document. As such, AD has patterned this risk assessment on a series of likely representative scenarios for each use site that are believed by AD to represent the vast majority of DDAC uses.   Based on the adverse effects for the endpoints, the average body weight of a female adult handler ( 60 kg) was used for the inhalation risk assessment.   Exposure factors used to calculate daily exposures to handlers were based on applicable data, if available. When appropriate data were lacking, values from a scenario deemed similar were used.   The maximum application rates allowed by labels were assumed.

1.3 Chemical Identification The Group I Quat Cluster ( DDAC) is a group of structurally similar quaternary ammonium compounds (" quats") that are characterized by having a positively charged nitrogen covalently bonded to two alkyl group substituents ( at least one C8 or longer) and two methyl substituents. In finished form, these quats are salts with the positively charged nitrogen ( cation) balanced by a negatively charged molecule ( anion). The anion for the quats in this cluster is chloride or bromide.

Currently, there are 4 active ingredients identified by the Agency that are registered and included in Case Number 350. Table 1.1 below provides the common chemical name, active ingredient code, CAS number, and chemical structure.

Table 1.1. Active Ingredients in the Group I Quat Cluster Identified by the AIJV Prod Code CAS RN Name Structure Chain Lengths 69149 7173 51 5 Didecyl Dimethyl Ammonium Chloride ( DDAC) N+

CH3 CH3 R Cl R R = C10 69166 5538 94 3 Dioctyl Dimethyl Ammonium Chloride N+

CH3 CH3 R Cl R R = C8 Page 12 of 97 Table 1.1. Active Ingredients in the Group I Quat Cluster Identified by the AIJV Prod Code CAS RN Name Structure Chain Lengths 69165 32426 11 2 Octyl Decyl Dimethyl Ammonium Chloride N+

CH3 CH3 R1 Cl R2 R1 = C8 ( variable %) R2 = C10 ( variable %)

69146 84540 07 8 Alkyl Dimethyl Ethyl Ammonium Bromide N+

CH3 CH3 R Br H3C R = C12 ( 5%) C14 ( 90%) C16 ( 5%)

1.4 Physical/ Chemical Properties Table 1.2 shows physical/ chemical characteristics that have been reported for DDAC.

Table 1.2. Physical/ Chemical Properties of DDAC Parameter DDAC Molecular Weight 362.08 Density 0.9216 g/ cm3 at 25 C Boiling Point NA Water Solubility Completely soluble Vapor Pressure 2.33E 11 mmHg 2.0 USE INFORMATION 2.1 Formulation Types and Percent Active Ingredient The products containing DDAC as the active ingredient ( a. i) are formulated as liquid ready to use, soluble concentrate, pressurized liquid, and water soluble packaging. Concentrations of DDAC in these products range from 0.08% to 80% as reported on the Master Label spreadsheet ( Appendix A).

2.2 Summary of Use Pattern and Formulations The Agency determines potential exposures to handlers of the product by identifying exposure scenarios from the various application methods that are plausible, given the label uses. These scenarios are identified in Appendix A. Based on a review of product labels, DDAC is the active ingredient in products used in the following use site categories: I ( Agricultural premises and equipment), II ( Food handling/ storage establishments premises and equipment), III ( Commercial, institutional and industrial premises and equipment), IV ( Residential and public access premises), V ( Medical premises and equipment), VIII ( Industrial processes and water systems), X ( Wood preservatives), XI ( Swimming pools), and XII ( Aquatic Areas). Page 13 of 97 From the scenarios in Appendix A, AD selected representative exposure scenarios to assess the labeled uses of DDAC in this document. These scenarios were selected to be representative of the vast majority of uses and are believed to provide high end degrees of dermal, inhalation, or incidental ingestion exposure. The representative scenarios assessed in this document are shown in Table 4.1 ( residential) and Table 6.1 ( occupational).

3.0 SUMMARY OF TOXICITY DATA 3.1 Acute Toxicity The acute toxicity data for DDAC are summarized below in Table 3.1 ( USEPA, 2006).

Table 2. Acute Toxicity Profile for DDAC Guideline Number Study Type/ Test substance (% a. i.) MRID Number/ Citation Results Toxicity Category 870.1100 ( § 81 1) Acute oral, rat ( Purity 65%) MRID 41394404 LD50 = 262 mg/ kg ( combined) II 870.1100 ( § 81 1) Acute oral, rat ( Purity 80%) MRID 42296101 LD50 = 238 mg/ kg ( combined) II 870.1200 ( § 81 2) Acute dermal, rabbit ( Purity 65%) MRID 42053801 LD50 = 2930 mg/ kg ( combined) III 870.1300 ( § 81 3) Acute inhalation, rat ( Purity not reported) MRID 00145074 TRID 455201010 LC50 = 0.07 mg/ L ( combined) I 870.2400 ( § 81 4) Primary eye irritation, rabbit ( Purity 80% a. i.) MRID 42161602 Corrosive. I 870.2500 ( § 81 5) Primary dermal irritation, rabbit ( Purity 80%) MRID 42161601 Corrosive. I 870.2600 ( § 81 6) Dermal sensitization, guinea pigs ( Purity 80%) MRID 46367601 Not a sensitizer. NA 3.2 Summary of Toxicity Endpoints Table 3.2 summarizes the toxicological endpoints for DDAC ( USEPA, 2006). The specific MRID numbers for toxicity studies are referenced in USEPA 2006 and not repeated in this document.

Table 3.2 Summary of Toxicological Endpoints for DDAC Exposure Scenario Dose Used in Risk Assessment ( mg/ kg/ day) Target MOE/ UF, Special FQPA SF for Risk Assessment Study and Toxicological Effects NOAEL( developmenta l) = 10 mg/ kg/ day FQPA SF = 1 UF = 100 ( 10x inter species extrapolation, 10x intra species variation) Prenatal Developmental Toxicity  Rat MRID 41886701 LOAEL = 20 mg/ kg/ day based on increased incidence of skeletal variations. Acute Dietary ( Females 13 50)

Acute RfD = 0.1 mg/ kg/ day ( for Females age 13 50) Page 14 of 97 Table 3.2 Summary of Toxicological Endpoints for DDAC Exposure Scenario Dose Used in Risk Assessment ( mg/ kg/ day) Target MOE/ UF, Special FQPA SF for Risk Assessment Study and Toxicological Effects Acute Dietary ( general population) An acute dietary endpoint was not identified in the data base. This risk assessment is not required NOAEL = 10 mg/ kg/ day FQPA SF = 1 UF = 100 ( 10x inter species extrapolation, 10x intra species variation Chronic Toxicity Study  Dog MRID 41970401 LOAEL = 20 mg/ kg/ day based on increased incidence of clinical signs in males and females and decreased total cholesterol levels in females. Chronic Dietary ( general population)

Chronic RfD = 0.1 mg/ kg/ day Non Dietary Exposures Incidental Oral Short Term NOAEL ( developmental) = 10 mg/ kg/ day Target MOE = 100 ( 10x interspecies extrapolation, 10x intraspecies variation) FQPA SF = 1 Prenatal Developmental Toxicity  Rat MRID 41886701 LOAEL = 20 mg/ kg/ day based on increased incidence of skeletal variations.

Incidental Oral Intermediate Term NOAEL = 10 mg/ kg/ day Target MOE = 100 ( 10x interspecies extrapolation, 10x intraspecies variation) FQPA SF = 1 Chronic Toxicity Study  Dog MRID 41970401 LOAEL = 20 mg/ kg/ day based on increased incidence of clinical signs in males and females and decreased total cholesterol levels in females.

Dermal, Short term ( formulated product, 0.13% a. i.) No endpoint identified. No dermal or systemic effects identified in the 21 day dermal toxicity study ( MRID 45656601) up to and including the limit dose of 1000 mg/ kg/ day Dermal, Short term ( TGAI 80% diluted to 0.1% ai) NOAEL( dermal) = 2 mg ai/ kg/ day ( 4 µ g ai/ cm2) a Target MOE = 100 ( 10x interspecies extrapolation, 10x intraspecies variation) 90 day Dermal Toxicity  Rat MRID 41305901 LOAEL = 6 mg ai/ kg/ day based on increased clinical and gross findings ( erythema, edema, exfoliation, excoriation, and ulceration)

Dermal, Intermediateand Long term ( formulated product) No appropriate endpoint identified. Page 15 of 97 Table 3.2 Summary of Toxicological Endpoints for DDAC Exposure Scenario Dose Used in Risk Assessment ( mg/ kg/ day) Target MOE/ UF, Special FQPA SF for Risk Assessment Study and Toxicological Effects Inhalation, Short Term NOAEL b = 10 mg/ kg/ day Target MOE = 100 ( 10x interspecies extrapolation, 10x intraspecies variation) FQPA SF = 1 Prenatal Developmental Toxicity  Rat MRID 41886701 LOAEL = 20 mg/ kg/ day based on increased incidence of skeletal variations.

Inhalation, Intermediate and Long Term NOAEL b = 10 mg/ kg/ day Target MOE = 100 ( 10x interspecies extrapolation, 10x intraspecies variation) FQPA SF = 1 Chronic Toxicity Study  Dog MRID 41970401 LOAEL = 20 mg/ kg/ day based on increased incidence of clinical signs in males and females and decreased total cholesterol levels in females.

UF = uncertainty factor, FQPA SF = special FQPA safety factor, NOAEL = no observed adverse effect level, LOAEL = lowest observed adverse effect level, PAD = population adjusted dose ( a = acute, c = chronic), RfD = reference dose, MOE = margin of exposure, LOC = Level of concern, NA = Not Applicable. a Short term dermal endpoint = ( 2 mg/ kg rat x 0.2 kg rat x 1000 ug/ mg) / 50 cm2 area of rat dosed = 8 µ g/ cm2. b an additional uncertainty factor of 10x is used for route extrapolation from an oral endpoint to determine if a confirmatory study is warranted.

3.3 FQPA Considerations The Agency ( USEPA, 2006) decided that the FQPA safety factor be removed for DDAC, based upon the existence of a complete developmental and reproductive toxicity database and the lack of evidence for increased susceptibility in these data.

4.0 RESIDENTIAL EXPOSURE ASSESSMENT 4.1 Summary of Registered Uses Products containing DDAC can be used as general cleaners, disinfectants, and deodorizers. These products are primarily for use on indoor surfaces such as hard floors, carpets, walls, bathroom fixtures, trash cans, toilet bowls, and household contents. Additionally, other uses in the home include liquid laundry deodorizers that are added to the final rinse of the wash cycle, algaecide/ bacteriocides that are added to portable humidifiers and swimming pools, and deodorizers that are sprayed on fabric. Residents may also be exposed to items that have been treated with DDAC in occupational settings, such as dimensional lumber for decks and play sets. Appendix A presents a summary of all exposure scenarios that may occur in residential settings based on examination of product labels. Table 4.1 identifies the representative exposure scenarios assessed in this document.

4.2 Residential Exposure The exposure scenarios assessed in this document for the representative uses selected by AD are shown in Table 4.1. The table also shows the maximum application rate associated Page 16 of 97 with the representative use and the EPA Registration number for the corresponding product label. It should be noted that for the calculation of application rates in which the density of the product is noted as 8.34 lb/ gal, the product is assumed to have the density of water because no product specific density is available. Handler exposures were assessed for the application of DDAC to indoor hard surfaces, carpets, humidifiers, and swimming pools. Post application exposures were assessed for dermal and/ or oral contact with treated surfaces including hard floors, carpets, textiles, lumber, and pool water. Post application/ bystander inhalation exposures were assessed for the humidifier use. DDAC has a low vapor pressure, and therefore, inhalation exposure is to the aerosol generation.

Table 4.1. Representative Uses Associated with Residential Exposure Representative Use Application Method Exposure Scenario Registration # Application Rate Indoor Hard Surfaces   Mopping   Wiping   Trigger pump spray ST Handler: adult dermala and inhalation ST Post app: child incidental ingestion and dermal > 10% ai 10324 134 1 to 10% ai 10324 80 < 1% ai NAb > 10% ai 0.0200 lb a. i./ gal ( 2 oz product/ gal water x 15.36% a. i. x 8.34 lb/ gal x 1 gal/ 128 oz)

1 to 10% ai 0.0043 lb ai/ gal ( 3.3% ai x 8.34 lb/ gal x 2 oz/ gal x 1 gal/ 128 oz)

Carpets   Low pressure spray ST Handler: adult dermala and inhalation ST Post app: child incidental ingestion and dermal > 10% ai 10324 108 1 to 10% ai 10324 81 < 1% ai NAb > 10% ai 0.0085 lb ai/ gal 13.02% ai x 8.34 lb/ gal x 1 oz/ gal x 1 gal / 128 oz)

1 to 10% ai 0.0088 lb ai/ gal ( 4.5% ai x 8.34 lb/ gal x 3 oz/ gal x 1 gal/ 128 oz) Swimming pool   Liquid pour ST Handler: adult dermala and inhalation ST Post app: ingestion ( child and adult) > 10% ai 10324 69 1 to 10% ai 1839 133 < 1% ai No products HANDLERS > 10% ai Heavy algae: 0.000017 lb ai/ gal ( 3 ppm) ( 50.0% x 5.25 oz/ 10,000 gal x 8.34 lb/ gal x 1 gal/ 128 oz)

1 to 10% ai Winterizing: 0.0000167 lb ai/ gal ( 10.0% x 128 oz/ 50,000 gal x 8.34 lb/ gal x 1 gal/ 128 oz)

POST APPLICATION Heavy algae: 0.0000488 lb ai/ gal ( 6 ppm) Page 17 of 97 Table 4.1. Representative Uses Associated with Residential Exposure Representative Use Application Method Exposure Scenario Registration # Application Rate ( 50.0% x 15 oz/ 10,000 gal x 8.34 lb/ gal x 1 gal/ 128 oz) Contacting Preserved Wood   NAc ST Post app: child incidental ingestion and dermal 6836 212 NA Wearing clothing and diapers treated during final rinse cycle of wash   NAd ST Post app: adult dermal; child incidental ingestion and dermal 1677 109 0.000733 lb ai/ lbs dry fabric ( 50.0% x 2.25 oz/ 100 lbs dry fabric x 8.34 lb/ gal x 1 gal/ 128 oz)

Wearing clothing treated with fabric spray   NAe ST Post app: adult dermal; child incidental ingestion and dermal 3573 69 0.011 lb ai/ gal ( 0.13% ai x 8.34 lb/ gal)

Humidifier   Liquid pour ST Handler: adult dermala and inhalation ST Post app: child and adult inhalation 10324 80 0.0043 lb ai/ gal ( 3.3% ai x 8.34 lb/ gal x 2 oz/ gal x 1 gal/ 128 oz)

a The dermal risks are based on the short term dermal endpoint ( i. e., rat study) regardless of the percent active ingredient in the product. b Application rates for products with < 1% ai are not needed because dermal irritation exposures are not assessed for products with < 1% ai and the inhalation exposures are assessed with the maximum application for all products. c The handlers scenarios were not assessed because the products can only be used by occupational handlers. d Handler exposures for application to laundry are represented by the application to humidifiers. e Handler exposures were not assessed because products contain < 1% ai.

4.2.1 Residential Handler Exposures The residential handler scenarios described in Table 4.1 were assessed to determine dermal and inhalation exposures. The scenarios were assessed using PHED and CMA data and the equations in Section 1.2, " Criteria for Conducting Risk Assessment." A summary of the PHED and CMA data sets are presented in Appendix B.

Unit Exposure Values: Unit exposure values were taken from the PHED data presented in HED's Residential SOPs ( USEPA, 1997) and from the CMA data from the EPA memorandum Evaluation of Chemical Manufacturers Association Antimicrobial Exposure Assessment Study ( USEPA, 1999). Page 18 of 97 $ For the mopping scenario, the CMA dermal ( hand) and inhalation unit exposure values for ungloved mopping were used ( 52 mg/ lb a. i. and 2.38 mg/ lb a. i., respectively). After normalization for the surface area of the hand ( 820 cm2), the dermal unit exposure value is 0.063 mg/ lb a. i/ cm2. These values are based on data collected from six replicates mopping floors and receiving exposure via contact with the mop or with the bucket.

$ For the wiping scenario, the CMA dermal ( hand) and inhalation unit exposure values for ungloved wiping were used ( 1,100 mg/ lb a. i. and 67.3 mg/ lb a. i., respectively). After normalization for the surface area of the hand ( 820 cm2), the dermal unit exposure value is 1.34 mg/ lb a. i/ cm2. These values are based on data collected from six replicates ( dental technicians) who used a finger pump sprayer to apply the product and then wiped the surfaces with a paper towel.

$ For trigger pump scenarios, the PHED dermal ( hand) and inhalation unit exposure values are 106 mg/ lb a. i. and 2.4 mg/ lb a. i., respectively. After normalization for the surface area of the hand ( 820 cm2), the dermal unit exposure value is 0.129 mg/ lb a. i/ cm2. The values are based on homeowners applying an insecticide packaged in an aerosol can to baseboards in kitchens and are representative of a handler wearing short pants and a short sleeve shirt, with no gloves.

$ For low pressure handwand, the CMA dermal ( hand) and inhalation unit exposure values for ungloved use of a low pressure spray are 132 and 0.681 mg/ lb a. i., respectively. After normalization for the surface area of the hand ( 820 cm2), the dermal unit exposure value is 0.161 mg/ lb a. i/ cm2. The values are based on data collected from eight replicates who hand sprayed carpet using 200 psi, then used a push broom rake to raise the carpet nap.

$ For liquid pour in swimming pool and humidifier scenarios, the cooling tower CMA data for liquid pour was used for dermal exposures. This set of data was used because no other CMA data sets represent ungloved replicates pouring liquid. The dermal hand unit exposure value is 0.196 mg/ lb a. i. After normalization for the surface area of the hand ( 820 cm2), the dermal unit exposure value is 0.000239 mg/ lb a. i/ cm2. For inhalation exposures, the CMA preservative data were used for swimming pool exposures. The inhalation unit exposure is 0.00346 mg/ lb a. i. and is based on 2 replicates. Although this unit exposure is based on minimal replicates, the exposure value is similar to the one found in PHED for a similar scenarios. For the humidifier tank scenario, CMA data for liquid pour of disinfectants were used. The inhalation unit exposure value is 1.89 mg/ lb a. i. The value is based on data collected from two gloved replicates involving pouring a disinfectant product from a jug into sterilization trays designed for dental instruments, adding water and instruments to the tray, removing the instruments, and discarding the old solution.

Quantity handled/ treated: The quantities handled/ treated were estimated based on information from various sources, including the Antimicrobial Division's estimates.

$ For mopping scenarios, it is assumed that 1 gallon of diluted solution is used.

$ For wiping and trigger pump spray scenarios, it is assumed that 0.5 liter ( 0.13 gal) of diluted solution is used.

$ For low pressure hand wand, it was assumed that 2 gallons are used in all indoor applications. Page 19 of 97 $ For liquid pour in swimming pool scenario, it was assumed that a residential pool contains 20,000 gallons of water.

$ For liquid pour in humidifier scenario, it was assumed that a humidifier with a 11 gallon tank would be treated, based on Holmes Model# HM4600 U 11. This humidifier releases 11 gallons/ 1,700 ft2/ 24 hours ( http:// www. holmesproducts. com/ estore/ product. aspx? CatalogId= 3& CategoryId= 112 0& ProductId= 582).

Duration of Exposure: The duration of exposure for most homeowner exposures is believed to be best represented by the short term duration ( 1 to 30 days). The reason that short term duration was chosen to be assessed is because the different handler and post application scenarios are assumed to be episodic, not daily. In addition, homeowners are assumed to use different products with varying activities, not exclusively DDAC treated products.

Results The resulting short term exposures and MOEs for the representative residential handler scenarios are presented in Tables 4.2 ( inhalation) and 4.3 ( dermal). The calculated inhalation MOEs are above the target MOE of 100 for all scenarios. The calculated dermal MOEs are above the target MOE of 100 for all scenarios. A confirmatory inhalation toxicity study may be warranted because inhalation MOE was below 1,000 for the wiping scenario ( MOE = 820). The dermal MOEs were below the target MOE of 100 for all scenarios except for the humidifier and swimming pool applications.

Table 4.2 Short Term Residential Handler Inhalation Exposures and MOEs Exposure Scenario Application Method Application Method Application Ratea ( lb ai/ gallon) Quantity Handled/ Treated per dayb ( gallons) Unit Exposure ( mg/ lb a. i.) Absorbed Daily Dose ( mg/ kg/ day) c MOE d ( Target MOE = 100)

Mopping 0.020 1 2.38 0.00079 13,000 Wiping 0.020 0.13 67.3 0.0029 3,400 Application to indoor hard surfaces Trigger Spray 0.020 0.13 2.4 0.00010 96,000 Application to Carpets Low Pressure Spray 0.0088 2 0.681 0.012 50,000 Application to Swimming Pools Liquid Pour 0.000017 20,000 0.00346 0.00002 510,000 Application to Humidifers Liquid Pour 0.0043 11 1.89 0.0015 6,700 a Application rates are the maximum application rates determined from EPA registered labels for DDAC. b Amount handled per day values are estimates or label instructions. c Absorbed Daily dose ( mg/ kg/ day) = [ unit exposure ( mg/ lb a. i.) x application rate ( lb ai/ gal) x quantity treated ( gal/ day) x absorption factor ( 1.0 for inhalation)]/ Body weight ( 60 kg for inhalation). d MOE = NOAEL / Absorbed Daily Dose. [ Where short term NOAEL = 10 mg/ kg/ day for inhalation]. Target MOE = 100. Page 20 of 97 Table 4.3 Short Term Residential Handler Dermal Risks Exposure Scenario Application Method Application Ratea ( lb ai/ gal) Quantity Handled/ Treated per dayb ( gallon) Hand Unit Exposure Adjusted for Surface Area ( mg/ lb ai/ cm2) c Dermal Skin Irritation Exposure d (: g/ cm2) MOE e ( Target MOE = 100)

Products with < 1% DDAC No dermal endpoint identified for products with < 1% DDAC Products with 1 to 10% DDAC ( NOAEL = 8 µ g/ cm2)

Mopping 0.0043 1 0.063 0.273 29 Wiping 0.0043 0.13 1.341 0.750 11 Application to indoor hard surfaces Trigger Spray 0.0043 0.13 0.129 0.072 110 Application to Carpets Low Pressure Spray 0.0088 2 0.161 2.832 3 Humidifier Liquid Pour 0.0043 11 0.000239 0.011 710 Application to swimming pools Liquid Pour 0.000017 20,000 0.000239 0.080 98 Products with > 10% DDAC ( NOAEL = 8 µ g/ cm2)

Mopping 0.020 1 0.063 1.27 6 Wiping 0.020 0.13 1.341 3.49 2 Application to indoor hard surfaces Trigger Spray 0.020 0.13 0.129 0.34 24 Application to Carpets Low Pressure Spray 0.0085 2 0.161 2.731 3 Application to swimming pools Liquid Pour 0.000017 20,000 0.000239 0.08 98 a Application rates are the maximum application rates determined from EPA registered labels for DDAC. b Amount handled per day values are estimates or label instructions. c Unit Exposure ( mg/ lb ai/ cm2) = Hand unit exposure from PHED or CMA ( mg/ lb ai) / surface area of hand ( 820 cm2). d Dermal Skin Irritation Exposure (: g/ lb ai/ cm2) = Unit Exposure ( mg/ lb ai/ cm2) x Application Rate ( lb ai/ gal) x Quantity Treated ( gal/ day) x 1,000 : g/ mg e MOE = NOAEL (: g/ cm2)/ Dermal Skin Irritation Exposure (: g/ cm2). [ Where short term dermal NOAEL = 8 µ g/ cm2]. Target MOE = 100.

4.2.2 Residential Post application Exposures For the purposes of this screening level assessment, post application scenarios have been developed that encompass multiple products, but still represent a high end exposure scenario for all products represented. As shown in Table 4.1, representative post application scenarios assessed include crawling on treated hard surfaces, carpets, and treated lumber such as decks/ play sets ( dermal and incidental oral exposure to children), wearing treated clothing from wash treatment and from spray treatment ( dermal exposure to adults and children and incidental oral exposure to children), using portable humidifiers ( adult and child inhalation exposure), and swimming in treated pools ( adult and child incidental ingestion).

Since no toxicological endpoint of concern was identified for dermal systemic adverse effects, post application dermal risks were assessed using the toxicological endpoint of concern for dermal irritation. The residential post application dermal risks were assessed by comparing the surface residue on the skin ( dermal skin irritation exposure) to the short term dermal irritation endpoint. It was assumed that during the exposure period, the skin repeatedly contacts the treated surface until a steady state concentration of residues is achieved on the skin. Page 21 of 97 <IP_ADDRESS> Hard Surface Floor and Carpets Dermal Exposure to Children from Treated Hard Floors and Carpets Exposure Calculations There is the potential for dermal exposure to toddlers crawling on hard floors and carpets after mopping or cleaning with DDAC. Risks were calculated for children contacting treated floors in residential homes. To determine toddler exposure to floor residues, the following equation was used:

E = AR x DTF x DRF x CF1 X CF2 ( Eq. 4)

Where:

E = Dermal skin irritation exposure ( µ g/ cm2); AR = Application rate ( lb/ ft2); DTF = Dermal transfer factor ( fraction, unitless); DRF = Disinfectant fraction remaining on floor ( unitless); CF1 = Conversion factor ( 4.54x108 µ g/ lb); CF2 = Conversion factor ( 0.00108 ft2/ cm2);

Assumptions Due to limited data, a number of conservative assumptions have been made:

$ No transferable residue data were available that could be used to estimate the transfer of DDAC from the floor to skin. Therefore, it is assumed that 10% of the deposition rate is available for dermal transfer from hard floors and 5% of the deposition rate is available for dermal transfer from carpets ( USEPA, 2000 and 2001).

$ No data could be found regarding the quantity of solution residue left on the floor after treatment. As a conservative measure, it has been assumed that 25% of the cleaning solution remains on the floor after the final cleaning/ mopping.

$ For mopping on hard floors, the labels did not provide information on the volume of disinfectant to be used for cleaning floors. It was assumed that the diluted treatment solution was applied at a rate of 1 gallon per 1,000 sq. ft. The maximum application rate on the product labels for application to hard surfaces is 0.020 lb ai/ gal ( see Table 4.1) for a residential setting. Therefore, the application rate used in the postapplication hard floor scenarios was 0.000020 lb ai/ ft2. For carpets, the labels stated that 1 gallon of diluted treatment solution should be applied at a rate of 1 gallon per 300 to 500 sq. ft for rotary floor machines. Using a rate of 1 gallon solution per 300 sq. ft. and a maximum application rate of 0.0088 lb ai/ gal ( see Table 4.1), the application rate used in the post application carpet scenarios was 0.0000293 lb ai/ ft2.

$ It was assumed that the exposed toddler plays regularly on the treated floor. In a residential home, short term exposure duration is most likely since homeowners are expected to clean the floor only intermittently. Results The calculation of the short term dermal doses and MOEs are shown in Table 4.4. Page 22 of 97 The dermal MOEs are below the target MOE of 100 ( MOE = 33 for hard surfaces and 45 for carpets).

Table 4.4. Short term Dermal Risks Associated with Post application Exposure from a Treated Hard Surface Floor and Carpet Exposure Scenario Application Rate ( lb ai/ sq ft) Product remaining after applying Percent Transfer Residue Dermal skin irritation exposure a ( µ g/ cm2) MOE Hard surface 0.000020 25% 10% 0.245 33 Carpet 0.0000293 25% 5% 0.180 45 a Dermal skin irritation exposure ( µ g/ cm2) = ( Application rate, lb/ ft2) x ( conversion factor, 4.54 E8 µ g/ lb) x ( conversion factor, 0.00108 ft2 / cm2) x ( product remaining after mopping, 25%) x ( dermal transfer factor, 10% for hard surface and 5% for carpets) b. MOE = NOAEL ( µ g/ cm2) / Surface Residue on skin ( µ g/ cm2). Short term dermal NOAEL is 8 µ g/ cm2. Target MOE = 100.

Child Incidental Ingestion Exposure to Treated Hard Floors and Carpets Exposure Calculations In addition to dermal exposure, toddlers crawling on treated hard floors will also be exposed to DDAC via incidental oral exposure through hand to mouth activity. To calculate incidental ingestion exposure to these chemicals due to hand to mouth transfer, the scenarios established in the Standard Operating Procedures ( SOPs) for Residential Exposure Assessments ( USEPA 2000 and 2001) were used. These scenarios use assumptions are similar to those used in calculating exposures due to dermal contact of DDAC from toddlers crawling on treated floors. Risks were calculated for children contacting treated floors in residential homes and in commercial day care centers. Typically the day care center scenario is assessed as the intermediate term duration because the frequency of cleaning is assumed to be greater than that of the residential setting. However, for DDAC, the short and intermediate term incidental oral endpoints are identical. The following equations were used to determine risks from hand to mouth transfer of pesticide residues to toddlers:

PDRnorm= SR x DTF x SA x FQ x ET x SE x CF1 ( Eq. 5) BW Where:

PDRnorm = Potential dose rate ( mg/ kg/ day); SR = Indoor Surface Residue ( µ g/ cm2); DTF = Dermal transfer factor ( unitless fraction); SA = Surface area of the hands that contact both the treated area, and the individuals mouth ( cm2/ event); FQ = Frequency of hand to mouth events ( events/ hr); SE = Saliva extraction efficiency ( unitless fraction); ET = Exposure time ( hrs/ day); CF1 = Unit conversion factor ( 0.001 mg/: g); and BW = Body weight ( kg) SR= AR x DRF x CF2 x CF3 Where: Page 23 of 97 SR = Surface residue on floor ( µ g/ cm2); AR = Application rate ( lb ai/ ft2); DRF = Disinfectant fraction remaining on floor ( 25%); CF2 = Unit conversion factor ( 4.54x108 µ g/ lb); and CF3 = Unit conversion factor ( 0.00108 ft2/ cm2)

Assumptions Due to limited data, a number of conservative assumptions have been made:

$ Toddlers ( 3 years old) were used to represent the 1 to 6 year old age group and are assumed to weigh 15 kg, the median for male and female toddlers ( USEPA 2000 and 2001).

$ Based on the SOP, it is assumed that the surface area used for each hand to mouth event is 20 cm2, and that there are 20 events per hour for short term exposures ( 90th percentile ( USEPA 2000 and 2001)).

$ For hard floors, the exposure time is 4 hours/ day, based on the time spent in the kitchen and bathroom for adults. For carpets, the exposure time is 8 hours/ day based on the total amount of time spent indoors for young children and subtracting the amount of time spent sleeping, eating, and bathing ( USEPA 2000 and 2001).

$ The saliva extraction efficiency is 50% ( USEPA 2000 and 2001)

$ No data could be found regarding the quantity of solution residue left on the floor after treatment. As a conservative measure, it has been assumed that 25% of the cleaning solution remains after the final mopping or cleaning.

$ No transferable residue data were available that could be used to estimate the transfer of DDAC from the floor to skin. Therefore, it was assumed that 10% of the deposition rate is available for dermal transfer from hard floors and 5% of the deposition rate is available for dermal transfer from carpets ( USEPA 2000 and 2001).

Results The calculation of the short term oral doses and MOEs are shown in Table 4.5. The oral MOEs are above the target MOE of 100 ( MOE = 760 for hard floors and 520 for carpets). Note: The short term duration is protective of the intermediate term exposures at a day care facility because the toxicity data are identical.

Table 4.5. Short term Incidental Oral Risks Associated with Post application Exposure from a Treated Hard Surface Floor and Carpet Exposure Scenario Appl. Rate ( lb ai/ sq ft) Percent transferable residue Product remaining after applying Surface area mouthed ( cm2/ event) Exposure Frequency ( events/ hr) Saliva Extraction Factor Exposure Time ( hrs/ day) Surface Residue on floor a ( µ g/ cm2) Potential Dose Rateb ( mg/ kg / day) Incidental Oral MOEc Hard Surface 0.000020 10% 25% 20 20 50% 4 2.45 0.013 760 Carpet 0.000029 3 5% 25% 20 20 50% 8 3.60 0.019 520 a Surface residue on floor ( µ g/ cm2) = ( application rate, lb ai/ ft2) x ( Disinfectant fraction remaining on floor, 25%) x ( conversion factor to convert lb to µ g, 4.54E+ 08 µ g/ lb) x ( conversion factor to convert ft2 to cm2, 1.08E 03 ft2/ cm2) b Potential Dose Rate ( mg/ kg/ day) = [( Surface residue on floor, µ g/ cm2) x ( transferable residue, 0.10 for hard floors and 0.05 for carpets) x ( exposure time, 4 hrs/ day for hard floors and 8hrs/ day for carpets) x ( surface area of hands, 20 cm2/ event) x ( exposure frequency, 20 events/ hr) x ( product remaining after applying, 25%) x ( extraction by saliva, 50 %) x ( conversion factor to convert : g to mg, 0.001 mg/ µ g)]/( body weight, 15 kg) Page 24 of 97 c MOE = NOAEL ( mg/ kg/ day) / potential dose rate ( mg/ kg/ day) [ Where oral NOAEL = 10 mg/ kg/ day for short term]. Target MOE = 100.

<IP_ADDRESS> Textiles Dermal Exposure to Laundered Clothing Adult and Child Exposure Calculations Some DDAC fabric softener/ sanitizing products are added to the final rinse cycle water to provide self sanitizing and bacteriostatic activity against odor causing organisms. To determine dermal skin irritation exposure to treated clothing, the guidance provided in Human and Environmental Risk Assessment ( HERA) Guidance Document ( 2003, 2005) was used. The following equation, modified from the basic equation provided in HERA ( 2003), is used to calculate dermal exposure:

Dermal Skin Irritation Exposure ( µ g/ cm2) = AR x F x FD x F1 x F2 x CF1 ( Eq. 6)

Where:

AR = Application rate in mg a. i./ mg weight of fabric; F = Weight fraction of the chemical left on the clothing after the final spin; FD = Fabric density ( mg/ cm2); F1 = Weight fraction transferred from clothing to skin; F2 = Weight fraction remaining on skin; and CF1 = Conversion factor, 1,000 µ g/ mg.

Assumptions   The application rate is 0.000733 mg a. i/ mg weight of fabric, based on product label # 1677 109.   In HERA ( 2003), it was determined that 2.5% of the chemical in the laundry detergent remains after the final rinse cycle. It is assumed that a washing machine containing laundry, detergent, and water would go through an agitation period, then spin dry, then refill with fresh water for rinsing, agitate, and then spin dry again. Assuming that the fraction of chemical removed during each spin dry cycle is the same, then:

Mf / Mi = Xspin 2 = 0.025 ( Eq. 7)

Where: Mf = Mass of chemical remaining on clothing after the final rinse, Mi = Mass of chemical originally added to laundry machine, and Xspin = Fraction of chemical remaining after each spin cycle.

The quantity Xspin is squared because the laundry and the detergent undergo two spin cycles. For assessment of fabric softener/ sanitizer, the fraction of chemical remaining will be equivalent to Xspin, since the fabric softener/ sanitizer, which is applied during the rinse Page 25 of 97 cycle, will only undergo one spin cycle. Taking the square root of both sides of Equation 7 gives an Xspin value of 0.158, or 15.8%.

  The fabric density is 10 mg/ cm2, which is the value provided in HERA ( 2003) for mixed cotton and synthetics.

  No leaching data were available that could be used to estimate a flux rate of the chemical from clothing. Exposures were calculated using a conservative transfer factor of 100%, which assumes that all residues are transferable from clothing surfaces to the skin, and using HERA's value of 1% transfer ( HERA, 2003).

  No dissipation data were available; therefore, the amount of DDAC remaining on the skin is assumed to be 100 percent.

Results The resulting short term dermal exposures and MOEs are presented in Table 4.6. The dermal MOE was above the target MOE of 100 assuming the 1% transfer, and therefore, not of concern. A confirmatory study to determine the percent transfer is warranted as the MOE estimated assuming 100% transfer is of concern.

Table 4.6. Short and Intermediate term Dermal Post application Exposure and MOE for Contacting Laundered Clothing   Adult and Child Parameter Value Rational Application rate 0.000733 mg a. i/ mg weight of fabric See Table 4.1 Weight fraction of residue remaining after final spin 15.8% Eq. 7 Fabric density 10 mg/ cm2 Mixed cotton and synthetics ( HERA 2003) Residue transfer factor from clothing to skin 1% and 100% HERA 2003 and EPA assumption Weight fraction remaining on skin 100% HERA, 2003 Dermal Exposurea 1% = 0.0116 µ g/ cm2 100% = 1.16 µ g/ cm2 Eq. 6 Dermal NOAEL 4 µ g/ cm2 Dermal endpoint selected Dermal Short term MOEb 1% = 690 100% = 7 Eq. 3b ( Target MOE = 100)

a Dermal Exposure ( µ g/ cm2) =( Application rate, 0.000733 mg a. i/ mg weight of fabric) x ( residue left after spin cycle, 15.8%) x ( fabric density, 10 mg/ cm2) x ( weight fraction transferred from clothing to skin) x ( weight fraction remaining on skin) x ( conversion factor, 1000 µ g/ mg) b MOE = NOAEL ( µ g/ cm 2 ) / dermal exposure ( µ g/ cm 2 ) [ Where short term dermal NOAEL = 8 µ g/ cm 2 ]. Target MOE = 100.

Incidental Oral Exposure to Laundered Clothing Adult and Child Exposure Calculations Oral exposure associated with toddlers mouthing clothing was assessed using an equation similar to that used for assessing dermal exposure to laundered clothing:

Oral Exposure ( mg/ kg/ day) = AR x F x FD x Smouthed x SE ( Eq. 8) Page 26 of 97 BW Where: AR = Application rate in mg a. i./ mg weight of fabric; F = Weight fraction of the chemical left on the clothing after the final spin; FD = Fabric density ( mg/ cm2); Smouthed = Surface area of fabric that is mouthed ( cm2); SE = Saliva extraction factor; and BW = Body weight ( kg).

Assumptions   The surface area of fabric mouthed is 100 cm2 ( HERA, 2003).   The saliva extraction factor is 50% ( USEPA 2000 and 2001).   Assumptions regarding fabric density and weight fraction of chemical left after final spin are identical to those used for the assessment of dermal exposure to laundered clothing.

Results The resulting short term oral exposure and MOE are presented in Table 4.7. The oral MOE was above the target MOE of 100.

Table 4.7. Short term Incidental Oral Postapplication Exposure and MOE for Contacting Laundered Clothing   Child Parameter Value Rational Application rate 0.000733 mg a. i/ mg weight of fabric See Table 4.1 Weight fraction of residue remaining after final spin 15.8% HERA 2005 Fabric density 10 mg/ cm2 Mixed cotton and synthetics ( HERA 2003) Surface area of clothing available for mouthing 100 cm2 HERA 2003 Saliva Extraction Factor 50% USEPA 2000 and 2001 Body weight 15 kg EPA 1997, median body weight Oral Exposurea 0.00386 mg/ kg/ day Eq. 8 Oral NOAEL 10 mg/ kg/ day Oral endpoint selected Short, intermediate term MOEb 2,600 Eq. 3 a Oral Exposure ( mg/ kg/ day) = ( Application rate, 0.000733 mg a. i/ mg weight of fabric) x ( residue left after spin cycle, 15.8%) x ( fabric density, 10 mg/ cm2) x ( surface area mouthed, 100 cm2) x ( Saliva extraction factor, 50%) / ( body weight, kg) b MOE = NOAEL ( mg/ kg/ day) / potential daily dose ( mg/ kg/ day) [ Where short term oral NOAEL = 10 mg/ kg/ day]. Target MOE = 100.

Dermal Exposure to Clothing Treated with Fabric Spray Exposure Calculations There is the potential for dermal exposure to children wearing clothing treated with a trigger pump spray product containing antimicrobials. The product label ( 3573 69) indicates to spray fabric until damp and to allow surface to dry before use. The dermal skin irritation exposure is calculated using following equation and assumptions: Page 27 of 97 E = C x TR ( Eq. 9)

Where: E = Dermal Skin irritation Exposure (: g/ cm2); and C = Concentration on clothing (: g ai/ cm2). TR = Transferable residue from clothing to skin (%);

C = A x WF x CF Where: C = Concentration on clothing (: g ai/ cm2); A = Water absorption rate of Whatman absorbent materials ( 198 mg/ cm2); WF = Weight fraction of product (% ai); and CF = Conversion factor ( 1,000 : g/ mg).

Assumptions   Whatman, Inc. sells " absorbent sinks", reels of absorbent materials for use in laboratories ( Whatman, 2005). One of their products, CF7, is composed of 100% cotton and is 1.9 mm thick. This product has a stated water absorption rate of 198 mg/ cm2. Since 1.9 mm seems a reasonable thickness for clothing, and it is assumed that the spray product is used until the clothing is thoroughly wet ( conservative assumption), an application rate of 198 mg product/ cm2 is assumed unless product specific data are submitted.   If data are not available from which a transfer factor could be estimated, potential doses are calculated using a conservative transfer factor of 100%, which assumes that all residues are transferable from clothing surfaces. Potential doses can also be calculated using a less conservative transfer factor of 5%, which is based on the amount of residue assumed to be transferable from carpeted surfaces ( USEPA, 2001) but confirmatory data will be requested to support this assumption.

Results The resulting short term oral exposure and MOE are presented in Table 4.8. The dermal MOEs were below the target MOE of 100 for both the 100% and 5% transfer factors ( MOEs are less than or equal to 1).

Table 4.8. Short term Dermal Risks Associated with Post application Exposure from a Clothing Treated with a Fabric Spray Weight fraction of product (% ai) Water absorption rate of Whatman absorbent materials ( mg/ cm2); Concentration of Clothing ( µ g/ cm2) Percent Transfer Residue Dermal skin irritation exposure a ( µ g/ cm2) MOE ( Target MOE = 100) 0.0013 198 257 100% 257 < 1 0.0013 198 257 5% 12.9 1 a Concentration on clothing ( µ g/ cm2) = % active ingredient / 100 * Product absorption rate ( 198 mg/ cm2)* conversion factor ( 1,000 µ g/ mg) b Dermal Skin Irritation Exposure ( µ g/ cm2) = ( concentration on clothing, µ g/ cm2) * ( percent transferable residue from textile). Page 28 of 97 c MOE = NOAEL ( µ g/ cm2) / Dermal Skin Irritation Exposure ( µ g/ cm2) [ Where short term dermal NOAEL = 8 µ g/ cm2. Target MOEs = 100.

Incidental Oral Exposure to Children Mouthing Clothing Treated with Fabric Spray Exposure Calculations There is the potential for incidental oral exposure to children from mouthing textiles treated with a trigger pump spray product containing DDAC.

Potential doses are calculated as follows:

PDD = C x SA x SE ( Eq. 10) BW where: PDD = potential daily dose ( mg/ kg/ day) C = concentration on clothing ( mg/ cm2) SE = saliva extraction efficiency (%) SA = Surface area mouthed ( cm2/ day) BW = body weight ( kg)

Assumptions   The concentration of the chemical on clothing was determined using same methodology as discussed in the previous section, post application dermal exposure to textiles.   The surface area of textiles mouthed by children is 100 cm2 ( HERA 2003).   The saliva extraction efficiency is 50% ( USEPA 2000 and 2001).   Toddlers ( 3 years old) are used to represent the 1 to 6 year old age group. For threeyear olds, the median body weight is 15 kg ( USEPA 1997).

Results Table 4.9 shows the calculation of the oral dose and oral MOE for children mouthing treated textiles. The MOE value is below the target MOE of 100 ( MOE = 12).

Table 4.9. Short term Post application Incidental Oral Exposures and MOEs for Children Contacting Clothing Treated with a Fabric Spray % a. i. Product absorption rate ( mg/ cm2) Concentration on clothinga ( mg/ cm2) Area mouthed ( cm2/ day) Saliva Extraction Factor Potential daily dose ( mg/ kg/ day) Incidental Oral MOEc 0.13 198 0.257 100 50% 0.857 12 a Concentration on clothing ( mg ai/ cm2) = % active ingredient/ 100 * Product absorption rate ( 198 mg/ cm2) b Potential Daily Dose ( mg/ kg/ day) = ( Concentration on clothing, mg/ cm2) * ( area mouthed, cm2/ day) * ( saliva extraction factor, unitless fraction) / ( body weight, kg). c MOE = NOAEL ( mg/ kg/ day) / absorbed potential daily dose [ Where short term oral NOAEL = 10 mg/ kg/ day]. Target MOE = 100. Page 29 of 97 <IP_ADDRESS> Treated Lumber Scenarios The Agency is concerned that there are potential residential post application exposure to children and adults exposed to DDAC treated wood. The potential outdoor residential post application exposure pathways considered are outlined below:

Children ° Dermal contact with DDAC treated wood products ( e. g., residential playground equipment, utility poles, posts, decks, shingles, fencing, lumber, piers, etc.);

° Incidental ingestion due to hand to mouth contact with DDAC treated wood products;

° Incidental ingestion of soil contaminated with DDAC;

° Dermal contact with soil contaminated with DDAC ( e. g., soil contaminated by treated decks and playground equipment); and Adults ° Dermal contact with wood from construction of decks and playground equipment;

° Incidental ingestion with wood from construction of decks and playground equipment.

Currently, there are no study data that can be used to estimate either exposure to adults during construction of wood decks or to children exposed to treated wood. Incidental ingestion exposure for adults is expected to be negligible and dermal contact for adults is expected to be lower than children for crawling on wood decks. Because children exhibit a more intense play contact on surfaces and have a higher surface area to body weight ratio, they would generally be considered to represent the maximum exposed individual.

Available data to assess the levels of DDAC in soil contaminated with DDAC treated wood do not exist at this time. In addition, leaching data were also not available. Because of this data gap, EPA was not able to estimate dermal and incidental ingestion residential postapplication exposures to soil contaminated with DDAC treated wood.

In this assessment, incidental ingestion and dermal exposures to children from contact with treated wood were estimated using DDAC exposure data from an occupational exposure study, " Measurement and Assessment of Dermal and Inhalation Exposures to Didecyl Dimethyl Ammonium Chloride ( DDAC) Used in the Protection of Cut Lumber ( Phase III)" ( Bestari et al., 1999, MRID 455243 04). The data were used for the following pathways: outdoor residential dermal contact with DDAC treated wood products ( e. g., residential playground equipment, utility poles, posts, decks, shingles, fencing, lumber, piers, etc.); and outdoor residential incidental ingestion due to hand to mouth contact with pressure treated wood products. The DDAC study measured dermal and inhalation exposures for various worker functions/ positions for individuals handling DDAC containing wood preservatives for non pressure treatment application methods and for individuals that could then come into contact with the preserved wood. Page 30 of 97 Outdoor Residential Dermal Contact with DDAC treated Wood Products Potential risks resulting from children's dermal contact with DDAC treated wood are assessed using maximum and average worker residue data for hands available in the DDAC study. The data in Table 4.10 were used to approximate the residues transferred from treated wood to skin. No other data are available ( e. g., no wipe data). The data from the following job descriptions in the DDAC study were chosen because of the possibility of the contact with dry treated wood. The average and maximum concentrations of these data ( 1.4 and 3.0 : g/ cm2) were assumed to be the dermal skin irritation exposure. The results indicate that the dermal MOEs are below the target MOE. However, these estimates are only reported as a range finder to determine if a wipe study is warranted. Based on the results the wipe study is warranted.

  End Stacker  Operates an automated stacking system at the end of the conveyor. Lumber stacked into loads.

  Stickman  Places sticks between stacks of wood manually. At some mills, this is done automatically by end stacker operator.

  Tallyman  Staples information sheet on to wood. May come in contact with treated lumber. ( Note: there were two reps available for tallyman)

Table 4.10. Hand Residue Data for DDAC for Handling of Dry Wood Job Description Total Hand Residue Data ( µ g/ cm2) End Stacker 1.2 Stickman 0.6 Tallyman 0.8 Tallyman 3.0 Average 1.4 Dermal Skin Irritation Exposurea ( µ g/ cm2) 1.4 and 3.0 MOEb ( Target MOE = 100) 6 average and 3 maximum a Dermal Skin Irritation Exposurea ( µ g/ cm2)= 1.4 and 3.0 µ g/ cm2 average and maximum hand residues, respectively b MOE = NOAEL ( µ g/ cm2) / dermal skin irritation exposure ( µ g/ cm2). Dermal NOAEL is 8 µ g/ cm2. Target MOE = 100.

Outdoor Residential Hand to Mouth Contact with DDAC treated Wood Products Potential risks from a child's hand to mouth activities are also assessed using worker residue data for hands that are available in the DDAC study. The most appropriate hand values to estimate potential residues of a child playing on treated decks/ playground structures are for the " dry" strata test subjects ( as defined above). These test subjects handled the dry treated wood from the non pressure treatments. Of the 20 test subjects measured for handling " dry" wood in the DDAC study, 19 had detectable hand values ( one value non detect) ranging from 0.04 to 3.0 µ g/ cm2 ( DDAC study page 104). The highest value ( most conservative) ( 3.0 µ g/ cm2) represents the " Tallyman" that wore no gloves ( DDAC study page 189).

The daily hand to mouth dose ( mg/ kg/ day) is estimated using the following equation: Page 31 of 97 Oral Dose t= Handt x Hand SA x SEF x Frequency x CF1 x ET ( Eq. 11) BW Where:

Handt = DDAC highest hand residue detected ( i. e.," Tallyman" working with dry wood ( µ g/ cm2)), Hand SA = hand surface area ( cm2/ event), SEF = saliva extraction factor ( unitless), Frequency = frequency of exposure event ( events/ hr), ET = exposure time ( hr/ day), CF1 = conversion factor ( 0.001 mg/ µ g), and BW = body weight ( kg). In addition to the hand residue value from the DDAC study, the following inputs are used in the hand to mouth estimate:

  The palmar surface area of 3 fingers of a toddler, 20 cm2, is used to estimate handmouthing as opposed to whole hand mouthing ( USEPA 2001).   The rate of hand to mouth activity for outdoor playing is 7 events per hour based on Freeman et. al ( 2001) at the 95th percentile.   The exposure time ( ET) is 2 hours and is consistent with the Agency's CCA assessment for time playing outdoors. Although the 2 hour duration represents " outdoor" time, it is used as a conservative estimate for playing on decks and playsets.   The saliva extraction factor ( SEF) is 0.5 and is based on the assumption of 50 percent removal efficiency of residues from hands by human saliva ( USEPA 2001).   The mean body weight of a child at age 3 is 15 kg.

The results of the hand to mouth estimates are presented in Table 4.11. The estimated short term MOE for the hand to mouth exposure is above the target MOE of 100 ( MOE = 360) and is not of concern. Because the dermal and oral endpoints represent different toxicological effects, an aggregate of the dermal ( discussed above) and oral MOEs are not appropriate.

Table 4.11: Residential Post application Incidental Oral Exposures with DDAC treated Wood Product Hand concentration from DDAC Study ( µ g/ cm2) Finger surface area ( cm2) Exposure Frequency for outdoor playing ( events/ hr) Saliva Extraction Factor Exposure Time ( hrs/ day) Average Daily Oral Dose a ( mg/ kg/ day) Incidental Oral MOEb ( Target MOE = 100)

3.0 20 7 0.5 2 0.028 360 a Average Daily Oral Dose ( mg/ kg/ day) = [ handt ( 3 µ g/ cm2 ) x Hand SA ( 20 cm2) x SEF ( 0.5) x Frequency ( 7 events/ hr) x Exposure Time ( 2 hrs/ day) x 0.001 mg/ µ g] / BW ( 15 kg) b MOE = NOAEL ( mg/ kg/ day) / daily dose ( mg/ kg/ day). For oral, NOAEL is 10 mg/ kg/ day. Target MOE = 100.

<IP_ADDRESS> Swimming Pools There are post application exposures associated with use of DDAC products in swimming pools and spas. For swimming pools, only incidental oral exposures are assessed in this document. Dermal and inhalation exposures are expected to be negligible due to the low Page 32 of 97 concentration of DDAC in pool water and the low vapor pressure of DDAC. Because the amount of exposure will most likely be greater for swimming pools than for spas, swimming pool scenarios were evaluated to represent the high end exposures associated with use of DDAC in pools and spas.

The SWIMODEL 3.0 was developed by EPA as a screening tool to conduct exposure assessments of pesticides found in swimming pools and spas ( Versar, 2003). The SWIMODEL uses well accepted screening exposure assessment equations to calculate the total worst case exposure for swimmers expressed as a mass based intake value ( mg/ event). The model focuses on potential chemical intakes only and does not take into account metabolism or excretion of the chemical of concern. Detailed information and the downloadable executable file are available at http:// www. epa. gov/ oppad001/ swimodel. htm. For this assessment, the actual model was not used, however, the same equations as provided in the SWIMODEL User's Manual ( version 3.0) were used in a spreadsheet format to estimate post application incidental oral and inhalation exposures for use of DDAC in swimming pools.

It should be noted that this exposure assessment identifies short term ( 1 30 days) and intermediate term ( 1 6 months) noncancer exposure doses based on the reported toxicology endpoints for DDAC. Because of the shorter exposure durations of these toxicological endpoints, conservative event based exposure assumptions are used to calculate upper bound daily dose estimates. The noncancer doses are not amortized over a lifetime.

Post application Incidental Ingestion Exposure through Swimming Pool Use The following equation was used to calculate incidental ingestion doses:

PDR = Cw x IR x ET ( Eq. 12) BW Where:

PDR = Potential dose rate ( mg/ kg/ day); Cw = Chemical concentration in pool water ( mg/ L); IR = Ingestion rate of pool water ( L/ hr); ET = Exposure time ( hrs/ day); and BW = Body weight ( kg).

Assumptions   For short term exposures, it was assumed that the concentration in water after shock treatment is 6.00 ppm ( 6.0 mg DDAC/ L). This concentration is based on the application of 7.5 oz to the pool skimmers/ lines per day ( regardless of the pool volume) for two consecutive days to treat heavy algae contamination as per label 10324 69. Thus the pool concentration would be 15 oz ( for two days of treatment) per pool. EPA uses a 20,000 gallon pool volume for the assessment. It is likely that the DDAC concentration in water would decrease after the 24 to 48 hour waiting period specified in the label but AD does not have data to indicate the dissipation of DDAC in pool water. Page 33 of 97   The ingestion rate is based on the value used in EPA's Residential SOPs ( USEPA 2000) and an EPA pilot study as discussed in ACC's swimmer survey ( ACC, 2002b).

  Exposure time for non competitive swimmers is based on the summary statistics from the National Human Activity Pattern Survey ( NHAPS) ( USEPA, 1996) whereas competitive swimmer exposure time data are based on the Agency's review of the American Chemistry Council ( ACC) study ( ACC, 2002b).

  The assumed body weight is 60 kg for adults, 48 kg for children ( age 11 14 years), and 30 kg for children ( age 7 10 years).

Table 4.12. Parameters for Swimming Ingestion Exposure and Dose Estimate Population Adult Child 7 10 yrs Child 11 14 yrs Type of Swimmer Competitive Non Competitive Competitive Non Competitive Competitive Non Competitive Cw ( mg/ L)   Short term exposure 6.0 6.0 6.0 6.0 6.0 6.0 IR ( L/ hr) 0.0125 0.0125 0.05 0.05 0.025 0.05 ET( hr/ day) 3 2a 1 3a 2 2.6a BW( kg) 60 60 30 30 48 48 a 90th percentile values Short term MOE values were calculated for ingestion of swimming pool water and are presented in Table 4.13. The calculations for short term incidental ingestion of DDAC indicate no risk concern for the non competitive or competitive swimming pool scenarios ( i. e., MOE> 100).

Table 4.13. Short Term Ingestion Dose and MOE for Residential Swimming Post Application Use Type Scenario Description Ingestion Dose ( mg/ kg/ day) Ingestion MOE a Adult, Competitive 0.0038 2,700 Adult, Non Competitive 0.0025 4,000 Child ( 7 10 yrs), Competitive 0.0100 1,000 Child ( 7 10 yrs), Non Competitive 0.030 330 Child ( 11 14 yrs), Competitive 0.0063 1,600 Swimming Pool Child ( 11 14 yrs), Non Competitive 0.0163 620 aMOE = NOAEL ( mg/ kg/ day)/ Ingestion Dose ( mg/ kg/ day). Short term Oral NOAEL = 10 mg/ kg/ day. Target MOE = 100 <IP_ADDRESS> Humidifiers Page 34 of 97 Inhalation Exposures for Portable Humidifiers  Adult and Child Inhalation exposures to DDAC used in portable humidifiers may also occur. To determine potential inhalation risk, the Multi Chamber Concentration and Exposure Model ( MCCEM v1.2) was used to provide a screening level estimate of potential inhalation risk to adults and children. MCCEM estimates average and peak indoor air concentrations of chemicals released from products or materials in houses, apartments, townhouses, or other residences. It estimates inhalation exposures to chemicals, calculated as single day doses, chronic average daily doses, or lifetime average daily doses. All dose estimates calculated by MCEMM are potential doses; they do not account for actual absorption into the body. Assumptions   The entire house is being humidified; therefore, a single chamber model was run.   A person is exposed to the release for either 8 hours a day or 24 hours a day.   The inhalation rates for the 8 hour exposure period are based on the sedentary activities ( 0.5 m3/ hr for adults and 0.4 m3/ hr for children). The inhalation rates for the 24 hour exposure period are based on the chronic inhalation rates ( 13.3 m3/ day for adults and 8.3 m3/ day for children) ( USEPA 1997).   For the 8 hr exposure duration assessment, the MOE was calculated using concentrations from 0 to 8 hours after the humidifier was turned on. For the 24 hr exposure assessment, it was assumed that the humidifier had already been running for the previous day; therefore, the concentrations from 24 to 48 hours after the fogger was turned on were used.   Release of the product occurs at a steady state throughout the day ( constant emission rate from one source).   The label indicated that 2 oz of product should be used per gallon. The label did not provide information on the quantity of solution that is released per hour. A release rate of 11 gallons/ 1,700 ft2/ 24 hours was used in this assessment based on the Holmes Model# HM4600U. ( http:// www. holmesproducts. com/ estore/ product. aspx? CatalogId= 3& CategoryId= 112 0& ProductId= 582). It was assumed that 11 gallons of the dilute solution would be released into the generic MCCEM house ( approximately 1,800 ft2 assuming 8 ft ceilings) over a 24 hour period. Based on an application rate of 0.0043 lb ai/ gal, approximately 0.895 g ai/ hr would be emitted into the house.   It was assumed that 100% of the product is inhalable.

Results The resulting short and intermediate term inhalation exposure and MOE for the representative post application inhalation scenarios are presented in Table 4.14 and 4.15. The 8 hr and the 24 hr MOEs for children and adults are below the target MOE of 100.

Table 4.14. Short and Intermediate term Post application Exposures and MOEs for Adults and Children in Houses Being Humidified ( 8 hr Exposure Duration) Parameter Value Rationale Page 35 of 97 Adult Child Housea Generic House ( 1 chamber) A portable humidifier that humidifies the entire house Activity Schedule Average concentration starting at 0 hour through 8 hours EPA Assumption Air Exchange Rate 0.18/ hr MCCEM default Application Rate 0.0043 lb ai/ gal Chemical specific product label Quantity Dilute Used 11 gallons/ 24 hours Holmes Model# HM4600 U Emission Ratea 0.895 gram ai/ hr Application rate ( lb ai/ gal) * Use amount ( gal/ hr) * CF ( g/ lb)

Body Weighta 60 kg 15 kg Average body weights for adults and young children Inhalation Ratea 12 m3/ day ( 0.5 m3/ hr) 9.6 m3/ day ( 0.4 m3/ hr) Sedentary rate for adults and young children ( USEPA, 1997)

MCCEM Outputs Average Concentration over 8 hrs ( mg/ m3) 5.59 5.59 Average of MCCEM calculated air concentrations from 0 to 8 hrs Dose ( mg/ kg/ day) 0.373 1.19 Average Conc. * 8 hrs * Inhal. Rate / BW Inhalation short and intermediate term MOEb 27 8 NOAEL ( 10 mg/ kg/ day) / Dose a Used as MCCEM input. Default values from MCCEM were used for all inputs not listed in the table above. b MOE = NOAEL ( mg/ kg/ day) / daily dose ( mg/ kg/ day) [ Where short, intermediate term inhalation NOAEL = 10 mg/ kg/ day]. Target MOE = 100.

Table 4.15. Short and Intermediate term Post application Exposures and MOEs for Adults and Children in Houses Being Humidified ( 24 hr Exposure Duration)

Value Parameter Adult Child Rationale Housea Generic House ( 1 chamber) A portable humidifier that humidifies the entire house Activity Schedule Average concentration starting at 24 hour through 48 hours EPA Assumption Air Exchange Rate 0.18/ hr MCCEM default Application Rate 0.0043 lb ai/ gal Chemical specific product label Quantity Dilute Used 11 gallons/ 24 hours Holmes Portable Humidifier Model# HM1285 Emission Ratea 0.895 gram ai/ hr Application rate ( lb ai/ gal) * Use amount ( gal/ hr) * CF ( g/ lb) Page 36 of 97 Table 4.15. Short and Intermediate term Post application Exposures and MOEs for Adults and Children in Houses Being Humidified ( 24 hr Exposure Duration)

Value Parameter Adult Child Rationale Body Weighta 60 kg 15 kg Average body weights for adults and young children Inhalation Ratea 13.3 m3/ day 8.3 m3/ day Chronic rate for adults and young children ( USEPA, 1997)

MCCEM Outputs Average Concentration over 24 hrs ( mg/ m3) 12.2 12.2 Average of MCCEM calculated air concentrations from 24 to 48 hrs Dose ( mg/ kg/ day) 0.90 2.24 Average Conc. * 24 hrs * Inhal. Rate / BW Inhalation short, intermediate term MOEb 11 5 NOAEL ( 10 mg/ kg/ day) / Dose a Used as MCCEM input. Default values from MCCEM were used for all inputs not listed in the table above. b MOE = NOAEL ( mg/ kg/ day) / potential daily dose ( mg/ kg/ day) [ Where short, intermediate term inhalation NOAEL = 10 mg/ kg/ day]. Target MOE = 100.

4.2.3 Data Limitations/ Uncertainties There are several data limitations and uncertainties associated with the residential handler and post application exposure assessments. These include the following:

  Surrogate dermal and inhalation unit exposure values were taken from the proprietary Chemical Manufacturers Association ( CMA) antimicrobial exposure study ( USEPA, 1999: DP Barcode D247642) or from the Pesticide Handler Exposure Database ( USEPA, 1998) ( See Appendix B for summaries of these data sources). Most of the CMA data are of poor quality, therefore, AD requests that confirmatory monitoring data be generated to support the values used in these assessments.   The quantities handled/ treated were estimated based on information from various sources, including HED's Standard Operating Procedures ( SOPs) for Residential Exposure Assessments ( USEPA 2000 and 2001). In certain cases, no standard values were available for some scenarios. Assumptions for these scenarios were based on AD estimates and could be further refined from input from registrants.   Some labels for products which can be used by homeowners in residential settings, as well as by workers in occupational settings, indicate that low pressure sprayers can be used for application of the disinfectant to hard, non porous surfaces such as floors and walls. A residential low pressure spray scenario was not assessed for the residential scenario because it is not a typical cleaning method for homeowners.   At this time, the Agency does not have exposure data to assess oral exposures to children and adults from using treated mouthpieces and reeds; therefore, the Agency is requesting residue data from treated mouthpieces and reeds.   In this assessment, incidental ingestion and dermal exposures to treated wood were estimated using DDAC data from the occupational exposure study. The degree of uncertainty ( under or overestimation) associated with using the DDAC hand residue data for dermal and oral exposure from contacting treated lumber are unknown. The amount of residue measured on the test subjects hands is variable and are influenced by Page 37 of 97 the duration of exposure, how often wood is contacted, and the degree of contact ( i. e., do the hand residues from the DDAC study mimic a child's play activity on decks and playsets?).   Available data to assess the levels of DDAC in soil contaminated with DDAC treated wood do not exist at this time. In addition, leaching data were also not available. Because of this data gap, EPA was not able to estimate dermal and incidental ingestion residential post application exposures to soil contaminated with DDAC treated wood.

5.0 RESIDENTIAL AGGREGATE RISK ASSESSMENT AND CHARACTERIZATION   To be determined in the risk assessment.

6.0 OCCUPATIONAL EXPOSURE ASSESSMENT The exposure scenarios assessed in this document for the representative uses selected by AD are shown in Table 6.1. The table also shows the maximum application rate associated with the representative use and the appropriate EPA Registration number for the product label. It should be noted that for the calculation of application rates in which 8.34 lb a. i./ gal is noted, the product is assumed to have the density of water because no product specific density is available. Appendix A presents a summary of all exposure scenarios that may occur in occupational settings based on examination of product labels.

Potential occupational handler exposure can occur in various use sites, which include: agricultural premises, industrial processes and water systems, food handling premises, commercial/ institutional/ industrial premises, medical premises, swimming pools, and aquatic areas. Additionally, occupational exposure can occur during the preservation of wood. For the preservation of wood, the procedure for treatment can occur in different ways, such that multiple worker functions were analyzed. Due to the complexity of the wood preservative analysis, the results for handler and post application exposures are presented separately in Section 6.3.

Table 6.1. Representative Exposure Scenarios Associated with Occupational Exposures to DDAC Representative Use Method of Application Exposure Scenario Registration # Application Rate Agricultural Premises ( Use Category I)

General Disinfectant for Hard Surfaces, Equipment, Vehicles   Low pressure handwand   High Pressure Spray   Wiping surface   Trigger pump spray   Mopping ST/ IT Handler: Inhalation 10324 81 0.0094 lb ai/ gal ( 4.5% a. i. x 3.2 fl. oz/ gal water x 1 gal/ 128 fl. oz x 8.34 lb/ gal Florist use)

Deodorize garbage cans 4.25 oz/ gal or 0.013 lb ai/ gal Typical rate 0.78 oz/ gal or 0.0023 lb ai/ gal Page 38 of 97 Table 6.1. Representative Exposure Scenarios Associated with Occupational Exposures to DDAC Representative Use Method of Application Exposure Scenario Registration # Application Rate Fogger   Liquid pour ST/ IT Handler ( mix/ load only): Inhalation ST Postapplication inhalation 10324 81 0.22 lb ai/ gal ( 4.5% a. i. x 74.8 fl. oz/ gal water x 1 gal/ 128 fl. oz x 8.34 lb/ gal)

Food Handling ( Use Category II)

  Low pressure handwand   Mop   Wipe   Trigger pump sprayer ST/ IT Handler: inhalation 10324 134 0.0200 lb a. i./ gal ( 2 oz product/ gal water x 15.36% a. i. x 8.34 lb/ gal x 1 gal/ 128 oz) Indoor Hard Surfaces ( including dishes, utensils, equipment)

  Flood   Immersion   Circulation ( Liquid pour) ST/ IT Handler: inhalation 1839 173 0.00196 lb ai/ gal ( 4.5% a. i. x 0.78 oz product/ gal water x 8.34 lb/ gal x 1gal/ 128oz)

Fogger   Liquid pour ST Postapplication Inhalation 10324 80 0.0065 lb ai/ gal ( 3.3% ai x 8.34 lb ai/ gal x 3 oz/ gal x 1 gal/ 128 oz)

Commercial/ Industrial/ Institutional Premises ( Use Category III)

  Low pressure handwand   Mop   Wipe   Trigger pump sprayer ST/ IT Handler: inhalation 10324 134 0.0200 lb a. i./ gal ( 2 oz product/ gal water x 15.36% a. i. x 8.34 lb/ gal x 1 gal/ 128 oz) Indoor Hard Surfaces   Liquid pour ST/ IT Handler: inhalation 10324 80 0.0043 lb a. i./ gal ( 2 oz / gal water x 3.3% a. i. x 8.34 lb/ gal x 1 gal/ 128 oz)

Carpets   Truck mounted extraction machines ( Liquid pour) ST/ IT Handler: Inhalation 1839 67 0.102 lb ai/ gal ( 13.02% a. i. x12 oz product/ gal water x 8.34 lb/ gal x 1gal/ 128oz)

Medical Premises ( Use Category V) Indoor Hard Surfaces   Mop ST/ IT Handler: inhalation 10324 134 0.0200 lb a. i./ gal ( 2 oz product/ gal water x 15.36% a. i. x 8.34 lb/ gal x 1 gal/ 128 oz)

Industrial processes and water systems ( Use Category VIII) Oil field operations  drilling mud and packing fluidsa   Liquid Pour ST/ IT Handler: Inhalation 1839 179 1.50 lb ai/ gal product ( 18% a. i. x 8.34 lb/ gal product) Small process water systems ( i. e., evaporative   Liquid Pour ST/ IT Handler: Inhalation 1839 129 4.17 lb ai/ gal product ( 50% ai x 8.34 lb ai/ gal) Page 39 of 97 Table 6.1. Representative Exposure Scenarios Associated with Occupational Exposures to DDAC Representative Use Method of Application Exposure Scenario Registration # Application Rate condensers, water scrubbing, wastewater treatment, pasteurizers, auxiliary service water, recirculating cooling water)   Metered pump ST/ IT Handler: Inhalation 10707 46 Maximum 0.0015 lb ai/ gal or 1,000 ppm ( 18% ai x 8.34 lb ai/ gal x 1,000 gal/ 1,000,000 gal) Maintenance 0.00015 lb ai/ gal or 100 ppm ( 18% ai x 8.34 lb ai/ gal x 100 gal/ 1,000,000 gal)

Wood Preservation ( Use Category X) Non pressure treatment of wood and wood products in wood treatment facilities Handler Worker Functions   Diptank Operators   Blender/ spray operators   Chemical operators Post Application Worker Functions   Graders   Trim saw operators   Clean up crews   Construction Workers ST/ IT/ LT Handler: inhalation ST/ IT/ LT Postapplication dermal and inhalation 6836 212 Diptank operators and blender/ spray operators: 3% ai solution All other worker functions: 80% ai in product Pressure treatment of wood and wood products in wood treatment facilities Handler Worker Functions   Treatment assistant   Treatment operator Post Application Worker Functions   Tram setter, stacker operator, loader operator, supervisor, test borer, and tallyman ST/ IT/ LT Handler: inhalation ST/ IT/ LT Postapplication dermal inhalation 6836 212 3% aib Swimming Pools ( Use Category XI) c Swimming pools/ Spas   Liquid pour ST/ IT Handler: inhalation 10324 69 1839 133 Maintenance ( IT/ LT): 0.00000417 lb ai/ gal ( 10.0% x 1 quart/ 50,000 gal x 8.34 lb/ gal x 1 gal/ 4 quarts)

Heavy algae ( ST): 0.000017 lb ai/ gal ( 50.0% x 5.25 oz/ 10,000 gal x 8.34 lb/ gal x 1 gal/ 128 oz) a For the secondary recovery application, the biocide is meter pumped into the produced water before it is reinjected into the formation or well. Since the biocide is added via metering pump ( continuous or batch) in the secondary recovery systems, the drilling rig worker handling the biocide via open pouring is expected to have a Page 40 of 97 higher exposure than the secondary recovery worker. Additionally, the current CMA data are not representative of handling the large volume assumed in this scenario. b The application rate for pressure treated wood preservation is based on the master label. The actual label only provides a retention rate. c The swimming pool scenario also represents the decorative pond/ fountain scenario in the aquatic area use site category because the application rates are very similar.

6.1 Occupational Handler Exposures The occupational handler scenarios included in Table 6.1 were assessed to determine inhalation exposures. The general assumptions and equations that were used to calculate occupational handler inhalation risks are provided in Section 1.2, Criteria for Conducting the Risk Assessment. The majority of the scenarios were assessed using CMA data and Equations 1 3. However, for the occupational scenarios in which CMA data were insufficient, other data and methods were applied.

DDAC dermal irritation exposures and risks were not estimated for occupational handler exposures. Instead, dermal irritation exposures and risks will be mitigated using default personal protective equipment requirements based on the toxicity of the end use product. To minimize dermal exposures, the minimum PPE required for mixers, loaders, and others exposed to end use products containing concentrations of DDAC that result in classification of category I, II, or III for skin irritation potential will be long sleeve shirt, long pants, shoes, socks, chemical resistant gloves, and chemical resistant apron. Once diluted, if the concentration of DDAC in the diluted solution would result in classification of toxicity category IV for skin irritation potential, then the chemical resistant gloves and chemicalresistant apron can be eliminated for applicators and others exposed to the dilute. Note that chemical resistant eyewear will be required if the end use product is classified as category I or II for eye irritation potential.

Unit Exposure Values ( UE): Inhalation unit exposure values were taken from the proprietary Chemical Manufacturers Association ( CMA) antimicrobial exposure study ( USEPA 1999: DP Barcode D247642) or from the Pesticide Handler Exposure Database ( USEPA 1998).

$ For the liquid pour scenarios, the unit exposure depends on the material being treated. The following CMA unit exposures were available and used for the assessment of the risk associated with the treatment of the specified materials. o Swimming pools, carpets, and oilfield operations ( drilling muds and packer fluids): CMA preservative data ( gloved). The inhalation unit exposure is 0.00346 mg/ lb a. i. and is based on 2 replicates. Although this unit exposure is based on minimal replicates, the exposure value is similar to the one found in PHED for a similar scenarios. o Indoor hard surfaces ( immersion, flooding, circulation and liquid pour) in Use Site Categories II and III: The inhalation unit exposure value for disinfectant liquid pour ( 1.89 mg/ lb a. i.) was used. o Small process water systems: CMA cooling tower data ( gloved). The inhalation unit exposure is 0.450 mg/ lb a. i. and is based on 5 replicates.

$ For the mopping scenarios, the CMA inhalation unit exposure value for ungloved mopping was used ( 2.38 mg/ lb a. i.). This value is based on data collected from six Page 41 of 97 replicates in which the applicator mopped the floor and received exposure via contact with the mop or with the bucket.

$ For the wiping scenarios, the CMA inhalation unit exposure value for ungloved wiping was used ( 67.3 mg/ lb a. i.). This value is based on data collected from six replicates ( dental technicians) who used a finger pump sprayer to apply the product and then wiped the surfaces with a paper towel $ For the low pressure handwand scenario, the CMA inhalation unit exposure value for low pressure spray was used ( 0.681 mg/ lb a. i.). This value is based on data collected from eight replicates in which the applicator hand sprayed carpet using 200 psi, then used a push broom rake to raise the carpet nap $ For the trigger pump spray scenarios, the PHED inhalation unit exposure value for aerosol applications ( PHED scenario 10) was used. The inhalation unit exposure is 1.3 mg/ lb a. i.

$ For the liquid/ metering pump scenarios, the unit exposure depends on the material being treated. The following CMA unit exposures were available and used for the assessment of the risk associated with the treatment of the specified materials. o Small process water systems: CMA cooling tower data. The inhalation unit exposure is 0.00432 mg/ lb a. i. and is based on 4 replicates.

$ For the high pressure/ high volume spray and medium pressure spray scenarios, the PHED inhalation unit exposure value for liquid/ open pour/ high pressure spray ( PHED scenario 35) was used ( 0.12 mg/ lb a. i.).

$ For airless sprayer scenarios, the occupational PHED inhalation unit exposure value for airless sprayer application ( PHED scenario 23) was used. The inhalation exposure value is 0.83 mg/ lb a. i.

$ For the fogging, ULV/ mist sprayer and automated system scenarios, it was assumed that most of the exposure to the handler will be due to preparing the fogger, and that the handler leaves the room immediately after fogging commences. Therefore, the available CMA disinfectant liquid pour inhalation unit exposure value was used. The inhalation unit exposure value is 1.89 mg/ lb a. i., respectively. This value is based on data collected from two gloved replicates involving pouring a disinfectant product from a jug into sterilization trays designed for dental instruments, adding water and instruments to the tray, removing the instruments, and discarding the old solution.

$ For the brush/ roller scenario, the occupational PHED inhalation unit exposure value for paintbrush applications was used ( single layer of clothing). The inhalation exposure value is 0.28 mg/ lb a. i.

Quantity handled/ treated: The quantity handled/ treated values were estimated based on information from various sources. The following assumptions were made:

  For the liquid pour scenarios, the quantity of the chemical that is handled depends on the material that is being treated. The following values were used for the different materials: o Swimming pools: 200,000 gallons. o Indoor hard surfaces ( immersion, flooding, circulation, and liquid pour): 2 gallons. o Carpets: 32 gallons, based on label 1839 81 ( solution is metered at 4 gallons per hour, assuming an 8 hour shift). o Oil field operations ( drilling muds and packer fluids): The following use information was used to estimate the amount of ai handled per day during oil Page 42 of 97 well activities. Biocide is typically added directly to drilling rig mud tanks via open pouring. Over a 3 to 6 week period, while a 13,000 ft well is being drilled, 1 to 2 drums ( 1 drum = 42 gallons) of biocide may be used if microbiological problems are encountered. Therefore, the short term exposure assessment used 5.6 gallons for the amount of biocide handled per day by the drilling rig worker [ i. e., ( 2 drums x 42 gal/ drum) / ( 5 days/ week x 3 weeks) = 5.6 gal/ day]. The intermediate term exposure assessment used 2.8 gallons for the amount of biocide handled per day by the drilling rig worker [ i. e., ( 2 drums x 42 gal/ drum) / ( 5 days/ week x 6 weeks) = 2.8 gal/ day]. Although crew changes may occur in drilling rig operations, typically a designated customer representative is responsible for the biocide feeding. Therefore, one person would be involved with the biocide application activities on a daily basis. o Small process water systems: Workers in small systems could manually pour up to 5 to 10 gallons of biocide into the system, but larger systems would utilize chemical pumps in order to save time and labor expense. However, for DDAC the application rate is low ( 16 oz product/ 1000 gallons of water), and therefore, the maximum amount used for closed systems is assumed for open pour. Therefore, AD assumed that workers handle 2.5 gallons of biocide per day when making open pour applications.

$ For the liquid/ metering pump scenarios the quantity that is handled depends on the material that is being treated. The following values were used for the different materials: o Small process water systems: AD has assumed that 20,000 gallons of water are treated daily when chemical pump applications are made.   For the mopping scenarios, it was assumed that two gallons of solution are used in the agricultural, food handling, and commercial/ institutional/ industrial settings and 45 gallons are used in the medical setting. The medical setting use amount is based on a janitor cleans approximately 28 hospital rooms a day and changing the cleaning water every three rooms ( Helwig 2003).   For the wiping and trigger pump spray scenarios, it was assumed that 1 liter or 0.26 gallons were used.   For the fogging scenario in the agricultural use site category, it was assumed that 150,000 ft3 is treated, based on the estimated dimensions of a poultry barn ( 300 ft x 50 ft x 10 ft). As the label directions only state to fog for one minute on maximum output per 4,000 ft3 and does not provide the amount of treatment solution to use per cubic foot, AD assumed that the maximum fogger output is 0.42 gallons/ min ( 25 gal/ hr). This value is the maximum output for the Mistermax fogger which is used to dispense fungicides, insecticides, germicides and disinfectants as wettable powders, emulsifiable concentrates, flowables or liquids in a variety of applications such as greenhouses, warehouses, food processing plants, and swine/ poultry houses ( http:// bugsource. com/ mistermax. html).   For the low pressure handwand scenario, it was assumed that 40 gallons of solution are used in agricultural scenarios ( USEPA 2001) and 2 gallons are used in all other applications.   For the high pressure spray scenario, it was assumed that 40 gallons of solution are used.

Duration of Exposure: The MOEs were calculated for the short and intermediate term durations for occupational handlers using the appropriate endpoints in Table 3.2. Exposure Calculations and Results Page 43 of 97 The resulting inhalation exposures and MOEs for the representative occupational handler scenarios are presented in Table 6.2. The calculated MOEs were above the target MOE of 100 for all scenarios.

A confirmatory inhalation toxicity study may be warranted because inhalation MOEs were below 1,000 for the following scenarios:

  Small process water systems, liquid pour: ST/ IT Inhalation MOE = 130   Agricultural fogging, mixing and loading: ST/ IT Inhalation MOE = 110   Medical premises, mopping: ST/ IT Inhalation MOE = 280   Wood Preservation ( non pressure treatment), blender/ sprayer: ST/ IT/ LT Inhalation MOE = 280 Table 6.2 Short , Intermediate and Long Term Inhalation Risks Associated with Occupational Handlers Exposure Scenario Method of Application Inhalation Unit Exposure ( mg/ lb a. i.) Application Rate Quantity Handled/ Treated per day Inhalation Daily Dose ( mg/ kg/ day) a Inhalation MOEb, c ( Target MOE = 100)

Agricultural Premises and Equipment ( Use Site Category I)

Mop 2.38 0.0094 lb ai/ gal 2 gallons 0.0075 13,000 High pressure/ high volume spray 0.12 0.0094 lb ai/ gal 40 gallons 0.00075 13,000 Low pressure handwand 0.681 0.0094 lb ai/ gal 40 gallons 0.0043 2,300 Trigger pump sprayer 1.3 0.0094 lb ai/ gal 0.26 gallons 0.000052 190,000 Application to hard surfaces, equipment, and vehicles Wipe 67.3 0.0094 lb ai/ gal 0.26 gallons 0.0027 3,600 Fogging ( mix/ load only) Liquid pour 1.89 1.88E 05 lb/ ft3 150,000 ft3 0.089 110 Food Handling/ Storage Establishments Premises And Equipment ( Use Site Category II)

Low pressure handwand 0.681 0.0200 lb ai/ gal 2 gallons 0.00045 22,000 Mop 2.38 0.0200 lb ai/ gal 2 gallons 0.0016 6,300 Wipe 67.3 0.0200 lb ai/ gal 0.26 gallons 0.0058 1,700 Trigger pump sprayer 1.3 0.0200 lb ai/ gal 0.26 gallons 0.00011 89,000 Application to indoor hard surfaces Immersion, Flooding, Circulation 1.89 0.00196 lb ai/ gal 2 gallons 0.00012 81,000 Commercial, Institutional and Industrial Premises and Equipment ( Use Site Category III )

Low pressure handwand 0.681 0.0200 lb ai/ gal 2 gallons 0.00045 22,000 Mop 2.38 0.0200 lb ai/ gal 2 gallons 0.0016 6,300 Wipe 67.3 0.0200 lb ai/ gal 0.26 gallons 0.0058 1,700 Trigger pump sprayer 1.3 0.0200 lb ai/ gal 0.26 gallons 0.00011 89,000 Application to indoor hard surfaces Liquid pour 1.89 0.0043 lb ai/ gal 2 gallons 0.00027 37,000 Application to carpets Liquid pour 0.00346 0.102 lb ai/ gal 32 gallons 0.00019 53,000 Page 44 of 97 Table 6.2 Short , Intermediate and Long Term Inhalation Risks Associated with Occupational Handlers Exposure Scenario Method of Application Inhalation Unit Exposure ( mg/ lb a. i.) Application Rate Quantity Handled/ Treated per day Inhalation Daily Dose ( mg/ kg/ day) a Inhalation MOEb, c ( Target MOE = 100)

Medical Premises and Equipment ( Use Site Category V)

Application to hard surfaces Mop 2.38 0.0200 lb ai/ gal 45 gallons 0.036 280 Industrial Processes and Water Systems ( Use Site Category VIII)

Liquid pour 0.45 4.17 lb ai/ gal product 2.5 gallons 0.078 130 Initial Dose ( ST): 1.50E 03lb ai/ gal water 20,000 gallons 0.0022 ST = 4,600 Small process water systems: Recirculating cooling tower Metering pump 0.00432 Maintenance Dose ( IT): 1.50E 04lb ai/ gal water 20,000 gallons 0.00022 IT = 46,000 5.6 gallons 0.00048 ST = 21,000 Oil field operations  drilling mud and packing fluids Liquid pour 0.00346 1.50 lb ai/ gal product 2.8 gallons 0.00024 IT = 41,000 Swimming Pools ( Use Site Category X) d Heavy algae Dose ( ST):

0.000017 lb ai/ gal 200,000 gallons 0.00020 ST= 15,000 Application to swimming pools Liquid pour 0.00346 Maintenance Dose ( IT/ LT):

0.00000417 lb ai/ gal 200,000 gallons 0.000048 IT= 210,000 ST = short term, IT = intermediate term, LT = long term, N/ A= No data available a Daily dose ( mg/ kg/ day) = [ unit exposure ( mg/ lb a. i.) x absorption factor ( 1.0 for inhalation) x application rate x quantity treated / Body weight ( 60 kg for inhalation). b MOE = NOAEL ( mg/ kg/ day) / Absorbed Daily Dose [ Where NOAEL = 10 mg/ kg/ day for all inhalation exposure durations]. Target MOE = 100. c The MOEs refer to short term and intermediate term duration unless indicated otherwise. d. The swimming pool scenario also represents the decorative pond/ fountain scenario in the aquatic area use site category because the application rates are very similar.

6.2 Occupational Post application Exposures Except for the post application scenarios assessed for fogging and wood preservatives in Section 6.3, occupational post application exposures are assumed to be negligible.

Fogging ( Food Processing Plant and Hatchery) Post application inhalation exposures only were assessed for entry into a building ( hatchery and food processing plant) after a fogging application, because dermal post application is presumed to be negligible. The inhalation exposure assessment was conducted using the Multi Chamber Concentration and Exposure Model ( MCCEM v1.2). MCCEM estimates average and peak indoor air concentrations of chemicals released from products or materials in houses, apartments, townhouses, or other residences. Although the data libraries contained in MCCEM are limited to residential settings, the model can be used to assess other Page 45 of 97 indoor environments. MCCEM has the capability to estimate inhalation exposures to chemicals, calculated as single day doses, chronic average daily doses, or lifetime average daily doses. ( All dose estimates are potential doses; they do not account for actual absorption into the body.)

The product, EPA Reg # 10324 80 ( 3.3% ai) with a maximum application rate of 0.0065 lb ai/ gal, was assessed for fogging use in a food processing plant. The label states to fog one quart of the diluted product per 1,000 cubic feet. All labels which can be used for fogging in food processing areas indicate that all personnel must vacate the room during fogging and for a minimum of 2 hours after fogging. Therefore, exposure was calculated for a person entering the food processing plant 2 hours after all the applied fogger has been deployed.

The product, EPA Reg # 10324 108 ( 13.02% ai) with a maximum application rate of 0.181 lb ai/ gal, was assessed for fogging use in hatcheries and incubators. After fogging, the label states that the building should be well ventilated and not to enter until 2 hours after fogging, unless wearing a self contained respirator and long pants/ long sleeves. The remaining labels for fogging use in hatchery rooms and incubator indicate re entry intervals of 0 to 2 hours. Therefore, exposure was calculated for a person entering the building immediately after all the applied fogger has been deployed and 2 hours after all the applied fogger has been deployed Assumptions used to calculate inputs for MCCEM and the calculated exposure values are presented in Table 6.3 for food processing plants and in Table 6.4 for hatcheries. The following assumptions were made:

  The area being fogged is a one chamber barn with dimensions of 300 ft x 50 ft x10 ft ( AD standard assumption).   For the food processing plant, the air exchange rate is 0.18 per hour ( MCCEM default based on a residential home). For a hatchery, the air exchange rate is 4 per hour based on the rate for a poultry barn ( Jacobson, 2005).   Fogging occurs instantaneously, so that the entire mass of product is mixed homogeneously with the indoor air as soon as fogging commences.   It is assumed that all of the aerosols are inhalable and/ or respirable.

Table 6.3. Short and Intermediate Term Inhalation Risks Associated with Post application Exposure to DDAC After Fogging a Food Processing Plant Parametera Value Rationale Dimensions 300x50x10 ft, 15,000 ft2 floor area, 150,000 ft3 ( 4,248 m3) volume EPA Assumption Air Changes per Hour ( ACH)* 0.18/ hr EPA Assumption Activity Pattern* 8 hr average concentration starting at expiration of 2 hr REI Based on product =

s re entry interval ( 10324 80) Concentration of Fogging Liquid 0.0065 lb ai/ gal Product Label ( See Table 6.1) Use rate 1 quart/ 1,000 ft3 Product label Amount applied to room 0.0258 g ai/ m3 ( Use rate) x ( Concentration) Body Weight 60 kg EPA Assumption Page 46 of 97 Table 6.3. Short and Intermediate Term Inhalation Risks Associated with Post application Exposure to DDAC After Fogging a Food Processing Plant Parametera Value Rationale Inhalation Rate 1.0 m3/ hr NAFTA Light Activity for Adults ( USEPA, 1997) MCCEM Output Average Concentration over 8 hrs ( mg/ m3) 2 hr re entry: 9.74 Average of MCCEM calculated air concentrations from Hour 2 to Hour 10 for 2 hr REI 8 hr Dose ( mg/ kg/ day) 2 hr re entry: 1.30 Average Conc. * 8 hrs * Inhal. Rate / BW 8 hr short term MOE 2 hr re entry: 7 NOAEL ( 10 mg/ kg/ day) / Dose * Used as MCCEM input. Default values from MCCEM were used for all inputs not listed in the table above Table 6.4. Short and Intermediate Term Inhalation Risks Associated with Post application Exposure to DDAC After Fogging a Hatchery Parameter Value Rationale Barn Dimensions* 300x50x10 ft, 15,000 ft2 floor area, 150,000 ft3 ( 4,248 m3) volume EPA Assumption Air Changes per Hour ( ACH)* 4/ hr Jacobson, 2005 Activity Pattern* 8 hr average concentration starting at expiration of 0 hr re entry interval and 2 hr re entry interval Based on product =

s re entry interval Application Rate of Fogging Liquid 0.181 lb ai/ gal. ( Note: Max rate 0.22 lb ai/ gal) Product Label ( See Table 6.1)

Use rate 0.42 gal/ 4,000 ft3 Product label states to fog 1 min/ 4,000 ft3. Output of 0.42 gal/ min from http:// bugsource. com/ mistermax. html Mass applied to barn 0.301 g ai/ m3 ( application rate) x ( use rate) Body Weight 60 kg EPA Assumption Inhalation Rate 1.0 m3/ hr NAFTA Light Activity for Adults ( USEPA, 1997) MCCEM Output Average Concentration over 8 hrs ( mg/ m3) 0 hr Re entry: 0.62 2 hr Re entry: 0.0114 Average of MCCEM calculated air concentrations from Hour 0 to Hour 8 for 0 hr re entry and Hour 2 to Hour 10 for 2 hr re entry 8 hr Dose ( mg/ kg/ day) 0 hr Re entry: 0.083 2 hr Re entry: 0.0015 Average Conc. * 8 hrs * Inhal. Rate / BW 8 hr short term MOE 0 hr Re entry: 120 2 hr Re entry: 6,600 NOAEL ( 10 mg/ kg/ day) / Dose A detailed report is presented in Appendix D, including hourly air concentrations. Based on MCCEM output, 8 hr MOE values were calculated. The MOE for fogging in the food processing plant ( 2 hr re entry interval) was below the target MOE of 100 ( MOE = 8). For fogging in hatcheries, the 8 hr MOE immediately following release and after a 2 hr reentry were above the target MOE of 100 ( MOE = 120 and 6,600, respectively). Because the 8 hr MOE for entering a hatchery immediately after fogging is below 1,000, the Agency may request a confirmatory inhalation toxicity study. The risks of concern for the food processing plant are attributed to the low air changes per hour assumed ( i. e., 0.18 ACH) in the assessment. For the poultry barn, ventilation rate was obtained from Jacobson ( 2005). The Page 47 of 97 assessment for food processing plants could be refined if a more accurate ventilation rate could be obtained.

6.3 Wood Preservation DDAC is used in products that are intended to preserve wood through both nonpressure treatment methods and pressure treatment methods. The exposure scenarios assessed in this document for the representative wood preservation uses selected by AD are shown in Table 6.1. Section 6.3.1 presents the exposure analysis for the handler and post application scenarios for non pressure treatment scenarios and Section 6.3.2 presents the exposure analysis for the handler and post application scenarios for pressure treatment scenarios.

Dermal irritation exposures from post application activities in the wood preservation treatment facility will be mitigated using default personal protective equipment requirements based on the toxicity of the end use product. Therefore, only inhalation exposures and risks are presented.

6.3.1 Non Pressure Treatment Scenarios ( Handler and Post application)

The proprietary study, " Measurement and Assessment of Dermal and Inhalation Exposures to Didecyl Dimethyl Ammonium Chloride ( DDAC) Used in the Protection of Cut Lumber ( Phase III)" ( Bestari et al., 1999, MRID 455243 04) identified various worker functions/ positions for individuals that handle DDAC containing wood preservatives for nonpressure treatment application methods and for individuals that could then come into contact with the preserved wood. The worker functions/ positions identified in the DDAC study are presented below.

Handler:   Blender/ spray operators are workers that add the wood preservative into a blender/ sprayer system for composite wood via closed liquid pumping.   Diptank Operators can be in reference to wood being lowered into the treating solution through an automated process ( i. e., elevator diptank, forklift diptank). This scenario can also occur in a smaller scale treatment facility in which the worker can manually dip the wood into the treatment solution.   Chemical operators for a spray box system consist of chemical operators, chemical assistants, chemical supervisors, and chemical captains. These individuals maintain a chemical supply balance along with flushing and cleaning spray nozzles.

Post application:   Graders, positioned right after the spray box, grade dry lumber by hand ( i. e. detect faults). In the DDAC study, graders graded wet lumber; therefore, the exposures to graders using DDAC are worst case scenarios.   Millwrights repair all conveyer chains and general up keep of the mill.   Clean up crews perform general cleaning duties at the mill.   Trim saw operators operate the hula trim saw and consist of operators and strappers. In the DDAC study, hula trim saw operators handled dry lumber.   Construction workers install treated plywood, oriented strand board, medium density fiberboard, and others. Page 48 of 97 The blender/ spray operator position was assessed using CMA unit exposure data and the remaining handler and post application positions were assessed using data from the DDAC study ( Bestari et al., 1999).

Blender/ Spray Operators The inhalation exposures and risks to the composite wood blender/ spray operators were assessed using Equations 1 through 3 in Section 1.2. The surrogate unit exposures were taken from the CMA study ( USEPA, 1999b). Specifically, the liquid pump preservative unit exposures were used in this assessment. The inhalation unit exposure is 0.000403 mg/ lb ai. These values are based on two replicates. The quantity of the wood being treated was derived from other wood preservative estimates ( USEPA, 2004) for the amount of wood slurry treated because no chemical specific data were available for DDAC. It was assumed that batches of wood slurry are treated in 10,000 gallon tanks, and that eight batches of wood slurry are treated per day ( one per hour for an 8 hr work shift). Additionally, it was assumed that each batch requires 3,000 gallons of preservatives and the remainder volume of the tank consists of wood slurry ( 7,000 gallons of wood slurry per batch). Since wood chips have a density of approximately 380 kg/ m3 ( SIMetric, 2005), the total amount of wood slurry treated per day would be 178,000 lbs ( 8 batches/ day x 7,000 gallons/ batch x 0.003785 m3/ gallon x 380 kg/ m3 x 2.2 lb/ kg). The assumptions used for batch sizes and the quantity of preservative needed are consistent with an assessment performed previously by the EPA ( USEPA 2003). The DDAC assessment was conducted using an application rate of 3% ai solution.