Occupational Risk Characterization Date completed: Feb 18, 2004 Prepared for:

Regulatory Management Branch II Antimicrobial Division Office of Pesticide Programs U. S. Environmental Protection Agency Arlington, VA 22202 Prepared by:

Jonathan Chen, Ph. D. Risk Assessment and Science Branch Antimicrobial Division Office of Pesticide Programs U. S. Environmental Protection Agency Arlington, VA 22202 TABLE OF CONTENTS BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.0 HAZARD ASSESSMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1 Adequacy of the Data Base . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2 Hazard Assessment of Inorganic Arsenic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.3 Hazard Assessment of Chromium ( VI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.4 FQPA Consideration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.0 EXPOSURE ASSESSMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 2.1 Identification of Potential Receptor Populations . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.1.1 Primary Occupational Handlers . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.1.2 Postapplication Occupational Receptors . . . . . . . . . . . . . . . . . . . 8 2.2 Identification of Potential Exposure Assumptions . . . . . . . . . . . . . . . . . . . . . . . . 9 3.0 RISK CHARACTERIZATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 3.1 Non carcinogenic Risk Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.2 Carcinogenic Risk Characterization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.2.1 Arsenic Carcinogenic Risk Characterization . . . . . . . . . . . . . . . 10 3.2.2 Chromium Carcinogenic Risk Characterization . . . . . . . . . . . . . 10 6.0 UNCERTAINTY ANALYSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 6.1 Uncertainties and Deficiencies in Hazard Assessment . . . . . . . . . . . . . . . . . . . . 19 6.1.1 Using Human Data Setting the Short term and Intermediate term Incidental Oral and Dermal Exposures End Points . . . . . . . . . . . . . . . . . 19 6.1.2 Dermal Absorption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 6.1.3 Arsenic Cancer Potency Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 6.2 Uncertainties and Deficiencies in Exposure Assessment . . . . . . . . . . . . . . . . . . 20 6.2.1 Data Gaps and Limitations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 7.0 CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 7.1 Primary Handler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 7.2 Postapplication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 8.0 REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 LIST OF TABLES Table 1. Acute Toxicity Summary of Arsenic Acid ( 75%) . . . . . . . . . . . . . . . . . . . . . . . . 3 Table 2. Toxicological Endpoints for Assessing Occupational Exposures/ Risks to Arsenic ( V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Table 3: Acute Toxicity Summary of the Chromium ( VI) . . . . . . . . . . . . . . . . . . . . . . . . . 6 Table 4. Toxicological Endpoints for Assessing Occupational Exposures/ Risks to Chromium ( VI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Table 5. Risk Characterization of Exposure Assessment to Primary Handler Short, Intermediate, and Long term B Non Cancer Risks to CCA . . . . . . . . . . . . . . . 11 Table 6. Risk Characterization of Exposure Assessment to Postapplication  Short, Intermediate, and Long term B Non Cancer Risks to CCA . . . . . . . . . . . . . . . 12 Table 7The Cancer Risks Associated with Exposure to Arsenic  Primary Application Handler 13 Table 8The Cancer Risks Associated with Exposure to Arsenic  Postapplication . . . . . . . . . . 14 Table 9The Cancer Risks Associated with Exposure to Chromium  Primary Handler . . . . . . . 15 Table 10 The Cancer Risks Associated with Exposure to Hexavalent chromium  Postapplication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Table 11 CCA Occupational Risk Assessment  Summary of Primary Handler Exposure Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Table 12 CCA Occupational Risk Assessment  Summary of Postapplication Exposure Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 1 BACKGROUND The purpose of risk characterization is to quantify the potential health risks to the potential receptors associated with exposure to the chemicals of concern. Inorganic Arsenical wood preservatives containing mixtures of arsenic, chromium and copper active ingredients are most commonly formulated as Chromated Copper Arsenate or CCA. The mixture prolongs the life of wood by preventing mold, fungi and insect attack. CCA is composed of a mixture of Arsenic (+ 5), Chromium (+ 6) and Copper (+ 2). The CCA is applied by forced into the wood under high pressure and is trapped in the intercellular spaces ( hence the name pressure treated wood). All non pressure treatments have been voluntarily cancelled by the registrants. The cancellation letter dated May 28, 2003, removed all non pressure treatments on EPA Reg. Nos. 3008 21, 75341 1 ( formerly 3008 8), and 75341 7 ( formerly 3008 68). There are no other CCA non pressure treatments.

Presented herein is the risk characterization of the " occupational" exposure and risk assessment for industrial workers involved in both pressure and non pressure wood treatments using Chromated Copper Arsenate. These risk estimates are calculated using the exposure parameters and exposure point concentrations developed in the Occupational Exposure and Risk Assessment Section and the toxicological endpoints reported in the Hazard Assessment Sections. The scope of EPA registered preservative chemicals covered by the term Chromated Copper Arsenate includes:

° Separate chromium ( Cr), copper ( Cu), and arsenic ( As) technical source, manufacturinguse products registered with the Agency for use in formulating inorganic arsenical preservative mixtures for the pressure treatment of wood; and ° Registered industrial end use product concentrates containing CCA chemical mixtures of Cr, Cu, and As intended for dilution with water to create work solutions for wood pressure treatments.

The current risk assessment is focusing on arsenic and chromium only. Cupric Oxide, the form of copper used in CCA treatment solutions, is not included as an active ingredient covered under this RED. Reregistration requirements for Cupric Oxide will be addressed separately in a RED document for Copper, and oxides, Case Number 4025, slated to be issued at a future date.

1.0 HAZARD ASSESSMENT 1.1 Adequacy of the Data Base The toxicological data base for the arsenic and chromium compounds found in inorganic arsenicals is adequate and will support reregistration eligibility for CCA and related wood preservative pesticides. The hazard assessment of inorganic arsenic and chromium are summarized in following sections. 2 1.2 Hazard Assessment of Inorganic Arsenic The acute toxicity summary of inorganic arsenic ( arsenic acid 7.5%) is summarized in Table 1. Humans are very sensitive to arsenic toxicity when compared with other experimental animals. Inorganic arsenic is acutely toxic, and ingestion of large doses leads to gastrointestinal symptoms, disturbances of cardiovascular and nervous system functions, and eventually death. The effects seen after short term arsenic exposure ( appearance of edema, gastrointestinal or upper respiratory symptoms) differ from those after longer exposure ( symptoms of skin and neuropathy). Some of the effects after short term exposure tended to subside gradually from the 5th day of the illness, despite continuous intakes of the poison. In contrast, symptoms of peripheral neuropathy appeared in some individuals even after the cessation of arsenical intakes On August 21, 2001, the OPP's Hazard Identification Assessment Review Committee ( HIARC) evaluated the toxicology data base of Inorganic Arsenic and established the toxicological endpoints for occupational exposure risk assessments. On October, 23 25 2001, the FIFRA Scientific Advisory Panel ( SAP) met and discussed some issues concerning the end points proposed by the HIARC. The conclusions related to inorganic arsenic are summarized in Table 2. 3 Table 1. Acute Toxicity Summary of Arsenic Acid ( 75%)

Guideline Reference No. Study Type MRID/ Data Accession No. Results Toxicity Category 81 1 ( OPPTS 870.1100) Acute Oral 404090 01 Mouse LD50 =

141 mg/ kg =  160 mg/ kg M+ F = 150 mg/ kg II 26356 Rat LD50 =

76 mg/ kg =  37 mg/ kg M+ F = 52 mg/ kg I 81 2 ( OPPTS 870.1200) Acute Dermal 26356 Rabbit LD50 =

1750 mg/ kg =  2300 mg/ kg II 81 3 ( OPPTS 870.1300) Acute Inhalation 404639 02 Mouse LC50 =

1.153 mg/ L =  0.79 mg/ L M+ F = 1.040 mg/ L II 81 4 ( OPPTS 870.2400) Primary Eye Irritation 26356 Rabbit 3/ 6 animals died by day 7. The 3 surviving animals were sacrificed on day 9 because of severe ocular irritation and corrosion. I 81 5 ( OPPTS 870.2500) Primary Skin Irritation 26356 Rabbit At 30 minutes, all animals showed moderate to severe erythema and slight to severe edema. All animals died prior to the 24 hour observation. I 81 6 ( OPPTS 870.2600) Dermal Sensitization 406462 01 Guinea Pig Not a Sensitizer 4 Table 2. Toxicological Endpoints for Assessing Occupational Exposures/ Risks to Arsenic ( V)

EXPOSURE SCENARIO DOSE ( mg/ kg/ day) ENDPOINT STUDY Acute Dietary This risk assessment is not required.

Chronic Dietary This risk assessment is not required.

Incidental Short and Intermediate Term Oral LOAEL= 0.05 MOE = 30 Based on edema of the face, gastrointestinal, upper respiratory, skin, peripheral and neuropathy symptoms Franzblau et al.( 1989) and Mizuta et al. ( 1956)

Dermal Short and Intermediate Term ( a) ( b) LOAEL= 0.05 MOE = 30 Based on edema of the face, gastrointestinal, upper respiratory, skin, peripheral and neuropathy symptoms Franzblau et al.( 1989) and Mizuta et al. ( 1956)

Dermal Long Term ( a) ( b) NOAEL= 0.0008 MOE = 3 Based on hyperpigmentation, keratosis and possible vascular complications. Tseng et al. ( 1968) and Tseng ( 1977)

Inhalation Short and Intermediate Term( c) LOAEL= 0.05 MOE = 30 Based on edema of the face, gastrointestinal, upper respiratory, skin, peripheral and neuropathy symptoms Franzblau et al.( 1989) and Mizuta et al. ( 1956)

Inhalation, Long Term NOAEL= 0.0008 MOE = 3 Based on hyperpigmentation, keratosis and possible vascular complications. Tseng et al. ( 1968) and Tseng ( 1977)

Carcinogenicity  Inhalation ( Inhalation Risk) CSF = 15.1 ( d) ( mg/ kg/ day) 1 ( For general Population) Lung cancer Chronic epidemiological inhalation study on humans CSF = 5.0 ( e) ( mg/ kg/ day) 1 ( For 8 hour working day)

Carcinogenicity  Oral Ingestion ( Oral and Dermal Risks) CSF= 3.67 ( f) ( mg/ kg/ day) 1 Internal organ cancer ( liver, kidney, lung and bladder) and skin cancer Chronic epidemiological oral study on humans Note: ( a). MOE = Margin of Exposure; NOAEL = No observed adverse effect level; and LOAEL = Lowest observed adverse effect level. ( b). The dermal absorption factor = 6.4%. ( Note: The FIFRA Scientific Advisory Panel recommended use of a lower value of 2 3%. The occupational assessment in the risk assessment uses 6.4 percent dermal absorption because the handlers and workers are exposed to the arsenic residue from the aqueous solution during mixing, loading, and handling or are exposed to newly treated, or " wet' wood which has arsenic residues on the surface of the wood). ( c). For inhalation exposure, a default absorption factor of 100% is used. Route to route extrapolation is used to estimate the exposed dose. ( d). Inhalation unit risk ( IUR) is derived from a 24 hour exposure inhalation unit risk with a value of 4.3 x 10 3 ( µ g/ m3) 1. To convert the IUR to a cancer slope factor in units of ( mg/ kg/ day)  1 for the general population = IUR ( µ g/ m3) 1 x 1/ 70 kg x 20 m3/ day x 1 mg/ 1,000 µ g ( EPA, 1989). ( e). For workers working 8 hour per day, the inhalation cancer slope factor ( CSF) derived from the 24 hour IUR for general population, is adjusted for an 8 hour work day. CSF for 8 hr work day = general population CSF of 15.1 ( mg/ kg/ day) 1 x ( 8hrs/ 24 hrs) = 5.0 ( mg/ kg/ day) 1. ( e). CSFis derived from the risk assessment associated with inorganic in drinking water are presented in 2000. The 2001 National Research Council ( NRC) update made specific recommendation with respect to the overall cancer risk estimates. The Agency is currently considering these recommendations and their potential impact on the cancer potency estimate. Based on the Agency's considerations of these recommendations, the current proposed cancer potency number may change in the final version of this risk assessment. 5 1.3 Hazard Assessment of Chromium ( VI) The acute toxicity of Chromium ( VI) is summarized in Table 3. In acute toxicity animal studies, administration of chromium ( VI) ( as chromic acid) by the oral, dermal, and inhalation routes resulted in significant acute toxicity as measured by lethality. The measured oral LD50 in rats was reported as 52 mg/ kg, the dermal LD50 as 57 mg/ kg, and the inhalation LC50 as 0.217 mg/ L, placing chromium ( VI) in Toxicity Category I for acute lethality. Human reports of death after ingestion of chromium show lethality at similar dose levels ( ATSDR, 1998). Chromium ( VI) is a significant eye and skin irritant, and severe allergic reactions consisting of redness and swelling of the skin have also been noted in exposed animals and humans.

Subchronic oral toxicity studies in experimental animals have demonstrated hematologic and hepatic effects from repeated oral exposure to Cr( VI) ( NTP, 1996). Oral ingestion of Cr( VI) compounds in experimental animals also results in significant developmental toxicity Trivedi et al ( 1989) observed reported decreased fetal weight, increased resorption, absence of uterine implantation, and increased abnormalities ( tail kinking, delay ossification of the cranium) in mice exposed to 250, 500, and 1,000 ppm potassium dichromate daily through drinking water during the entire gestational period. Other investigators have also reported developmental effects ( Junaid et al., 1996; Kanojia, et al., 1996). Cr ( VI) is known to be carcinogenic in humans by the inhalation rout of exposure (( U. S. EPA 2000), and some data suggest that orally ingested hexavalent chromium may also be carcinogenic by this route, although further investigation is necessary ( Costa, 1997).

On August 28, 2001, the OPP's Hazard Identification Assessment Review Committee ( HIARC) evaluated the toxicology data base of Cr( VI) and established the toxicological endpoints for occupational exposure risk assessments. On October, 23 25 2001, the antimicrobial Division, Office of Pesticide Programs presented a series of issues to the FIFRA Scientific Advisory Panel ( SAP) which included questions on the validity of the toxicological endpoints for Cr( VI). The endpoints selected for Cr( VI) for use in CCA occupational risk assessment as a result of the HIARC meeting and the FIFRA SAP meeting are summarized in Table X  4. To address of concern for potential skin irritation and allergic potential for Cr( VI) from occupational exposure, and in accordance with OPP policy, it was concluded that precautionary label statements should be included on the CCA wood preservative treatment solutions used in pressure treatment facility.

1.4 FQPA Consideration No FQPA concerns will be addressed in assessing risks associated with occupational exposure scenarios.

2.0 EXPOSURE ASSESSMENT The purpose of the exposure assessment is to estimate the nature and magnitude of potential chemical intakes for various receptors. Detailed exposure assessment associated with occupational exposure to CCA is addressed in the Occupational Exposure and Risk Assessment Section. Table 3: Acute Toxicity Summary of the Chromium ( VI) 6 Guideline Study Type [ Substance] MRID/ Literature Results Toxicity Category 81 1 ( OPPTS 870.1100) Acute Oral/ Rat [ Chromic Acid, 100% a. i.] 434294 01 LD50 =

56 mg/ kg =  48 mg/ kg M+ F = 52 mg/ kg I 81 2 ( OPPTS 870.1200) Acute Dermal/ Rabbit [ Chromic Acid, 100% a. i.] 434294 02 LD50 =

> 48 mg/ kg =  48 mg/ kg M+ F = 57 mg/ kg I 81 3 ( OPPTS 870.1300) Acute Inhalation/ Rat [ Chromic Acid, 100% a. i.] 434294 03 LC50 =

0.263 mg/ L =  0.167 mg/ L M+ F = 0.217 mg/ L I 81 4 ( OPPTS 870.2400) Primary Eye Irritation [ Various Cr( VI) compounds] Literature Waiver Corrosive I 81 5 ( OPPTS 870.2500) Primary Dermal Irritation [ Various Cr( VI) compounds] Literature Waiver Corrosive I 81 6 ( OPPTS 870.2600) Dermal Sensitization / Guinea Pig [ Various Cr( VI) compounds] Literature Strong sensitizer 7 Table 4. Toxicological Endpoints for Assessing Occupational Exposures/ Risks to Chromium ( VI)

EXPOSURE SCENARIO DOSE ( mg/ kg/ day) ENDPOINT STUDY Acute Dietary This risk assessment is not required.

Chronic Dietary This risk assessment is not required.

Incidental Shortand Intermediate Term Oral ( a) NOAEL= 0.5of chromic acid [ 0.12 of Cr( VI)]

MOE = 100 based on the increased incidence of maternal mortality and decreased body weight gain at LOAEL of 2.0 [ 0.48 of Cr ( VI)] Developmental/ Rabbit Tyl, 1991 Dermal Exposure ( b)

( All Durations) Because dermal irritation and dermal sensitization are the primary concern through the dermal exposure route, no toxicological end point is selected for use in assessing dermal exposure risks to chromium.

Inhalation Exposure ( All Durations) ( a) LOAEL= 0.002 mg/ m3; ( or 2.3 x 10 4 mg/ kg/ day) MOE = 100 nose and throat symptoms observed at the 0.002 mg/ m3 level Linberg and Hedenstierna, 1983.

Carcinogenicity  Inhalation ( Inhalation Risk) CSF= 40.6 ( c)( mg/ kg/ day) 1 ( For general Population) Lung tumors IRIS CSF= 13.5 ( d)( mg/ kg/ day) 1 ( For 8 hour working day)

Note: ( a). MOE = Margin of Exposure; NOAEL = No observed adverse effect level; and LOAEL = Lowest observed adverse effect level. ( b). The dermal absorption factor for Cr( VI) = 1.3% for handler dermal contact with chromated arsenical pesticides. ( c) The 24 hours inhalation unit risk is 1.16 x 10 2 ( µ g/ m3) 1 which can also be expressed as 0.0116 m3/

g. To convert the air concentration to a dose to yield units of kg day/ mg or ( mg/ kg/ day) 1 the unit risk is expressed mathematically as 0.0116 m3/

g x day/ 20 m3 x 1000

g/ mg x 70 kg = 40.6 ( mg/ kg/ day) 1 ( EPA, 1989). ( d) For workers working 8 hour per day, the inhalation cancer slope factor ( CSF) derived from the 24 hour CSF for the general population, is adjusted for an 8 hour work day . CSF for 8 hr work day = general population CSF of 40.6 ( mg/ kg/ day) 1 x ( 8hrs/ 24 hrs) = 13.5 ( mg/ kg/ day) 1. 8 2.1 Identification of Potential Receptor Populations The exposure scenarios developed for this RED Chapter are representative of potential occupational exposures to the chemicals of concern over short term ( 1 day to 1 month), intermediate term ( 1 6 months), and long term ( > 6 months) exposure durations. Potential occupational exposures were identified for both the handlers and postapplication activities.

2.1.1 Primary Occupational Handlers The CCA is applied by forcing into the wood under high pressure and is trapped in the intercellular spaces ( hence the name pressure treated wood). In this risk assessment, the potential occupational workers involved in the application of the product will be addressed.

For wood treatment plant workers involved with pressure treatments, one potential exposure scenario is identified.

° Potential Exposure Scenario 1  Worker applying diluted chromated arsenical liquid treatment solutions at a pressure treatment plant using an automated/ closed delivery system. In this risk assessment, the risk associated with both Treatment Operator ( TO) and Treatment Assistant ( TA) will be assessed. These worker activities involve applying the product using an automated/ closed delivery system to mechanically pump a 1 2% CCA C treatment solution from the " work tank" to the pressure treatment cylinder ( i. e., retort) to pressure treat a charge of wood. Exposure may occur to treatment operators and treatment assistants while handling leads and charge chains, opening and closing retort doors, as well as cleaning and maintenance of systems. Treatment operators operate and monitored application system valves and controls, they sometimes opened and closed cylinder doors, and they supervise the insertion and removal of charges ( loads of dried, debarked poles or untreated ties) of poles from the treatment cylinders 2.1.2 Postapplication Occupational Receptors Postapplication exposure occurs following the application of a pesticide product. In the wood pressure treatment plants, postapplication occurs when job functions require that there be contact with freshly treated wood and pressure treatment machinery ( e. g., retort door) or pipes, or when occupying treatment areas directly after pesticide applications. A study by the Chemical Manufacturer's Association ( CMA) entitled the " Assessment of Potential Inhalation and Dermal Exposure Associated with Pressure Treatment of Wood with Arsenical Products" ( MRID 455021 01) was submitted to EPA as part of the reregistration requirements. In this report, six different potential postapplication occupational receptors are identified.

° Loader Operator  Worker scenario pertains to a formulating facility or wood pressure treatment facility. Worker operates self propelled vehicles that are used to 9 load wood products onto and off of trams, and to move charges into and out of treatment cylinders and to and from load out areas. Worker may perform certain out of cab tasks such as collect tank samples, perform test boring and lab analysis of treatment solutions of wood.

° Test Borer  Worker scenario pertains to a wood pressure treatment facility. Worker takes pole cores to test for CCA penetration. May also test concentration of lots of CCA, and perform other QC laboratory duties.

° Tram Setter  Worker positions trams for loading, places wood spacers on trams where needed to elevate wood to be treated. Does all lead and chain handling for that site. Removes and shreds all bands from treated stacks of lumber. Sweeps and pressure washes pad areas. Picks up and disposes of treated wood waste. May also perform various labor and cleanup duties in drip pad area.

° Supervisor  Supervisor duties were not fully described in the study report.

° Tally Man  Main duties include counting and inspection of incoming and outgoing truckloads of wood products, and supervision of loading and unloading of lumber trucks at drip pad and elsewhere. May also perform some treatment related duties, such as end marking of treated items or chaining of charges for treatment. His office was located immediately adjacent to the drip pad.

° Stacker Operator  Worker operates a lumber stacking device, which arranges treated boards in stacks for banding and shipment to customers, and removes wood spacer sticks from bundles of treated boards. This worker manually positions ends of all treated boards moving through devices so they are evenly positioned.

2.2 Identification of Potential Exposure Assumptions In order to calculate the exposure of chemicals as a result of exposure to the chemicals of concern ( CCA) and to estimate the associated potential health risks, a number of exposure parameters must first be quantified. In this risk assessment, the exposure estimates for both the primary occupational handlers ( wood treatment plant workers involved with pressure treatments), and the postapplication exposure are using the results of the " Assessment of Potential Inhalation and Dermal Exposure Associated with Pressure Treatment of Wood with Arsenical Products" ( MRID 455021 01) submitted by the American Chemistry Council ( ACC, 2001).

3.0 RISK CHARACTERIZATION The risk characterization ( both non carcinogenic and carcinogenic risks) associated with occupational handler and postapplication exposure to the chemicals of concern ( inorganic arsenic and chromium) in CCA are presented.

3.1 Non carcinogenic Risk Characterization 10 Based on the discussions in the hazard assessment and exposure assessment, the total daily exposure and Margin of Exposure ( MOE) for each potential exposure receptor and potential exposure routes are calculated. The non carcinogenic risk characterizations of exposure assessment for the primary exposure scenarios for both arsenic and hexavalent chromium are summarized in Table 5. The non carcinogenic risk characterizations of exposure assessment for the postapplication potential exposure receptors for both arsenic and hexavalent chromium are summarized in Table 6. In general, if the MOE is greater than the specified target MOE, the risk is considered not of concern. Otherwise, when the MOE is less than the specified uncertainty factor, exposure to the specific chemical through the potential exposure route is considered to indicate a potential health concern. In both Tables 5 and 6, the exposure scenarios with the calculated MOE in the cells marked with (

) pose a risk of concern. Since no inhalation studies are available, the OPP's Hazard Identification Assessment Review Committee ( HIARC) selected the same studies as for the dermal risk assessments. For arsenic risk assessment, the HIARC recommended that the dose from both dermal and inhalation exposure be combined and then be compared to the oral LOAEL of 0.05 mg/ kg/ day for short and intermediate term exposure and the oral NOAEL of 0.0008 mg/ kg/ day for long term exposure to evaluate the total risk concern. However, because the dermal exposure is higher than the inhalation exposure, there is minimum increase in the combined risk.

3.2 Carcinogenic Risk Characterization The carcinogenic concerns for occupational exposure to both inorganic arsenic and hexavalent chromium are presented. In general, if the calculated cancer risk is greater than 1x 10 6, the associated exposure scenario is posing a cancer risk of concern. Otherwise, if the calculated cancer is less than 1x 10 6 , the associated exposure scenario is not of concern.

3.2.1 Arsenic Carcinogenic Risk Characterization The dermal and inhalation cancer risks associated with inorganic arsenic for primary exposure scenarios are calculated and summarized in Table 7. The dermal and inhalation cancer risks associated with inorganic arsenic for postapplication exposure receptors are calculated and summarized in Table 8. The cells marked with (

) stand for the exposure scenario pose a risk concern.

3.2.2 Chromium Carcinogenic Risk Characterization There is no carcinogenic concern for dermal exposure to hexavalent chromium. The potential cancer risks associated with inhalation exposure to the hexavalent chromium in CCA are calculated and summarized in Table 9 and 10 The exposure scenarios for handler and postapplication activities are all of concern ( i. e., handler risks are 1.8 x 10 4 and 1.6 x 10 4 ; postapplication risks ranged from 1.6 x 10 4 to 2.0 x 10 4). However, it is important to note that all inhalation monitoring samples were below the limit of detection ( i. e., cancer risks are based on ½ LOD). The analytical technique used to determine the amount of Cr+ 6 in the sample was inadequate. 11 Table 5. Risk Characterization of Exposure Assessment to Primary Handler Short, Intermediate, and Long term   Non Cancer Risks to CCA Exposure Scenario ( Scen. #) Chemical of Concern Dermal Inhalation Dermal + Inhalation Short

and Intermediateterm MOEa Long term MOEb Short,

and Intermediateterm MOEc Long term MOEd Short,

and Intermediateterm MOEc Long term MOEd ( 1) Applying Liquid Formulations at Pressure Treatment Plants using an Automatic/ Closed Delivery System ( Operating and Closing the Retort)

Treatment Operator ( TO) Arsenic ( As) 16 (

)

( Target MOE 30) 0.3 (

)

( Target MOE 3) 467 ( Target MOE 30) 7 ( Target MOE 3) 16 (

)

( Target MOE 30) 0.3 (

)

( Target MOE 3)

Hexavalent chromium ( Cr) NA NA 7 (

)

( Target MOE 100) 7 (

)

( Target MOE 100)

( 1) Applying Liquid Formulations at Pressure Treatment Plants using an Automatic/ Closed Delivery System ( Operating and Closing the Retort)

Treatment Assistant ( TA) Arsenic ( As) 48 ( Target MOE 30) 0.8 ( Target MOE 3) 769 ( Target MOE 30) 12 ( Target MOE 3) 45 ( Target MOE 30) 0.7 ( Target MOE 3)

Hexavalent chromium ( Cr) NA NA 7 (

)

( Target MOE100) 7 (

)

( Target MOE 100)

Footnotes:

a Short and Intermediate term dermal MOE = dermal NOAEL / Short and Intermediate term dermal daily dose ( mg/ kg/ day). Where As LOAEL = 0.05 mg/ kg/ day.

b Long term MOE = dermal NOAEL/ Long term dermal daily dose ( mg/ kg/ day). Where As NOAEL = 0.0008 mg/ kg/ day.

c Short, Intermediate term inhalation MOE = inhalation NOAEL / Short, Intermediate term inhalation dose ( mg/ kg/ day). Where As LOAEL = 0.05 mg/ kg/ day, and Cr NOAEL = 6.9 x 10 5 mg/ kg/ day ( derived from a LOAEL = 2.4 x10 4 mg/ m3).

d Long term inhalation MOE = inhalation NOAEL or LOAEL / long term inhalation dose. Where As NOAEL = 0.0008 mg/ kg/ day and Cr NOAEL = 6.9 x 10 5 mg/ kg/ day ( derived from a LOAEL = 2.4 x10 4 mg/ m3).

e MOE = inhalation NOAEL or LOAEL / long term inhalation dose. Where As NOAEL = 0.0008 mg/ kg/ day and Cr NOAEL = 6.9 x 10 5 mg/ kg/ day ( derived from a LOAEL = 2.4 x10 4 mg/ m3).

NA Not applicable NOTE: Recommended Dermal MOE for Arsenic: short and intermediate term = 30; long term = 3.

Recommended Inhalation MOE for Arsenic: short and intermediate term = 30, long term = 3.

Recommended Inhalation MOE for Chromium VI: Short, intermediate and long term = 100 The exposure scenario with the calculated MOE in the cell marked with (

) pose a risk concern. 12 Table 6. Risk Characterization of Exposure Assessment to Postapplication  Short, Intermediate, and Long term   Non Cancer Risks to CCA Exposure Scenario ( Scen. #) Chemical of Concern Dermal Inhalation Dermal + Inhalation Short

and Intermediateterm MOEa Long term MOEb Short,

and Intermediateterm MOEc Long term MOEd Short,

and Intermediateterm MOEc Long term MOEd ( 1) Loader Operator Arsenic ( As) 21 (

) 0.3 (

) 581 9 20 (

) 0.3 (

)

Chromium ( Cr) NA NA 6 (

) 6 (

)

( 2) Test Borer Arsenic ( As) 263 4 1471 24 223 4 Chromium ( Cr) NA NA NA NA

( 3) Tram Setter Arsenic ( As) 8 (

) 0.1 (

) 195 3 8 (

) 0.1 (

)

Chromium ( Cr) NA NA 6 (

) 6 (

)

( 4) Supervisor Arsenic ( As) 16 (

) 0.3 (

) 325 5 15 (

) 0.3 (

)

Chromium ( Cr) NA NA 6 6 (

)

( 5) Tally Man Arsenic ( As) 18 (

) 0.3 (

) 1136 18 18 (

) 0.3 Chromium ( Cr) NA NA NA NA NA NA ( 6) Stacker Operator Arsenic ( As) 38 0.6 (

) 1515 24 38 0.6 (

)

Chromium ( Cr) NA NA 6 (

) 6 (

)

Footnotes:

a Short and Intermediate term dermal MOE = dermal NOAEL / Short and Intermediate term dermal daily dose ( mg/ kg/ day). Where As LOAEL = 0.05 mg/ kg/ day.

b Long term MOE = dermal NOAEL/ Long term dermal daily dose ( mg/ kg/ day). Where As NOAEL = 0.0008 mg/ kg/ day.

c Short, Intermediate term inhalation MOE = inhalation NOAEL / Short, Intermediate term inhalation dose ( mg/ kg/ day). Where As LOAEL = 0.05 mg/ kg/ day, and Cr NOAEL = 6.9 x 10 5 mg/ kg/ day ( derived from a LOAEL = 2.4 x10 4 mg/ m3).

d Long term inhalation MOE = inhalation NOAEL or LOAEL / long term inhalation dose. Where As NOAEL = 0.0008 mg/ kg/ day and Cr NOAEL = 6.9 x 10 5 mg/ kg/ day ( derived from a LOAEL = 2.4 x10 4 mg/ m3).

NA Not applicable NOTE: Recommended Dermal MOE for Arsenic: short and intermediate term = 30; long term = 3.

Recommended Inhalation MOE for Arsenic: short and intermediate term = 30, long term = 3.

Recommended Inhalation MOE for Chromium VI: Short, intermediate and long term = 100.

The exposure scenario with the calculated MOE in the cell marked with (

) pose a risk concern. 13 Table 7 The Cancer Risks Associated with Exposure to Arsenic  Primary Application Handler Exposure Scenario ( Scen. #) Route of Exposure Cancer Slope Factor ( CSF) ( per mg/ kg/ day) Lifetime Average Daily Dose ( mg/ kg/ day) Cancer Risks ( a)

( 1) Treatment Operator ( TO) Dermal 3.67 ( b) 1.12E 3 4.1E 3 (

)

Inhalation 5.0 ( c) 3.9E 5 1.9E 4 (

)

( 1) Treatment Assistant ( TA) Dermal 3.67 ( b) 3.8E 4 1.4E 3 (

)

Inhalation 5.0 ( c) 2.4E 5 1.2E 4 (

)

Note: ( a). Cancer Risk = Slope Factor x Lifetime Average daily Dose ( LADD). The exposure scenario with the calculated cancer risk in the cell marked with (

) pose a risk concern. ( b). CSF is derived from the risk assessment associated with inorganic in drinking water are presented in 2000. The 2001 National Research Council ( NRC) update made specific recommendation with respect to the overall cancer risk estimates. The Agency is currently considering these recommendations and their potential impact on the cancer potency estimate. Based on the Agency's considerations of these recommendations, the current proposed cancer potency number may change in the final version of this risk assessment. ( c). For workers working 8 hour per day, the inhalation potency factor is derived from the 24 hour inhalation potency factor for general population. CSF = 15.1 ( mg/ kg/ day) 1 x ( 8hrs/ 24 hrs) = 5.0 ( mg/ kg/ day) 1. 14 Table 8 The Cancer Risks Associated with Exposure to Arsenic  Postapplication Exposure Scenario ( Scen. #) Route of Exposure Cancer Slope Factor ( Q*) ( per mg/ kg/ day) Lifetime Average Daily Dose ( mg/ kg/ day) Cancer Risks ( a)

( 1) Loader Operator ( LO) Dermal 3.67 ( b) 8.9E 4 3.3E 3 (

)

Inhalation 5.0 ( c) 3.1E 5 1.5E 4 (

)

( 2) Test Border ( TB) Dermal 3.67 ( b) 6.8E 5 2.5E 4 (

)

Inhalation 5.0 ( c) 1.2E 5 6.0E 5 ( 3) Tram Setter ( TS) Dermal 3.67 ( b) 2.3E 3 8.4E 3 (

)

Inhalation 5.0 ( c) 9.4E 5 4.7E 4 (

)

( 4) Supervisor ( S) Dermal 3.67 ( b) 1.1E 3 4.1E 3 (

)

Inhalation 5.0 ( c) 5.6E 5 2.8E 4 (

)

( 5) Tally Man ( TM) Dermal 3.67 ( b) 1.0E 3 3.8E 3 (

)

Inhalation 5.0 ( c) 1.6E 5 8.0E 5 ( 6) Stacker Operator ( SO) Dermal 3.67 ( b) 4.8E 4 1.8E 3 (

)

Inhalation 5.0 ( c) 1.2E 5 6.0E 5 Note: ( a). Cancer Risk = Slope Factor x Lifetime Average daily Dose ( LADD). The exposure scenario with the calculated cancer risk in the cell marked with (

) pose a risk concern. ( b). CSF is derived from the risk assessment associated with inorganic in drinking water are presented in 2000. The 2001 National Research Council ( NRC) update made specific recommendation with respect to the overall cancer risk estimates. The Agency is currently considering these recommendations and their potential impact on the cancer potency estimate. Based on the Agency's considerations of these recommendations, the current proposed cancer potency number may change in the final version of this risk assessment. ( c). For workers working 8 hour per day, the inhalation potency factor is derived from the 24 hour inhalation potency factor for general population. CSF = 15.1 ( mg/ kg/ day) 1 x ( 8hrs/ 24 hrs) = 5.0 ( mg/ kg/ day) 1. 15 Table 9 The Cancer Risks Associated with Exposure to Chromium  Primary Handler Exposure Scenario ( Scen. #) Route of Exposure Cancer Slope Factor ( Q*) ( per mg/ kg/ day) Lifetime Average Daily Dose ( mg/ kg/ day) Cancer Risks ( a)

( 1) Treatment Operator ( TO) Dermal NA NA NA Inhalation 13.5( b) 1.3E 5 1.8E 4 (

)

( 1) Treatment Assistant ( TA) Dermal NA NA NA Inhalation 13.5( b) 1.2E 5 1.6E 4 (

)

Note: ( a). Cancer Risk = Slope Factor x Lifetime Average daily Dose ( LADD). The exposure scenario with the calculated cancer risk in the cell marked with (

) pose a risk concern. ( b). For workers working 8 hour per day, the inhalation potency factor is derived from the 24 hour inhalation potency factor for general population. CSF = 40.6 ( mg/ kg/ day) 1 x ( 8hrs/ 24 hrs) = 13.5 ( mg/ kg/ day) 1. 16 Table 10 The Cancer Risks Associated with Exposure to Hexavalent chromium  Postapplication Exposure Scenario ( Scen. #) Route of Exposure Cancer Slope Factor ( Q*) ( per mg/ kg/ day) Lifetime Average Daily Dose ( mg/ kg/ day) Cancer Risks ( a)

( 1) Loader Operator ( LO) Dermal NA NA

Inhalation 13.5 ( b) 1.5E 5 2.0E 4 (

)

( 2) Test Border ( TB) Dermal NA NA

Inhalation 13.5 ( b) NA NA ( 3) Tram Setter ( TS) Dermal NA NA

Inhalation 13.5 ( b) 1.5E 5 2.0E 4 (

)

( 4) Supervisor ( S) Dermal NA NA

Inhalation 13.5 ( b) 1.5E 5 2.0E 4 (

)

( 5) Tally Man ( TM) Dermal NA NA

Inhalation 13.5 ( b) NA NA ( 6) Stacker Operator ( SO) Dermal NA NA

Inhalation 13.5 ( b) 1.2E 5 1.6E 4 (

)

Note: ( a). Cancer Risk = Slope Factor x Lifetime Average daily Dose ( LADD). The exposure scenario with the calculated cancer risk in the cell marked with (

) pose a risk concern. ( b). For workers working 8 hour per day, the inhalation potency factor is derived from the 24 hour inhalation potency factor for general population. CSF = 40.6 ( mg/ kg/ day) 1 x ( 8hrs/ 24 hrs) = 13.5 ( mg/ kg/ day) 1. 17 Table 11 CCA Occupational Risk Assessment  Summary of Primary Handler Exposure Scenarios Cells Marked with (

) Stand for the exposure Scenario Pose a Risk Concern Potential Receptor ( Receptor #) Chemical of Concern Non Carcinogenic Cancer Dermal Inhalation Dermal + Inhalation Dermal Inhalation Short, and Intermediateterm Long term Short, and Intermediateterm Long term Short, and Intermediateterm Long term ( 1) Applying Liquid Formulations at Pressure Treatment Plants using an Automatic/ Closed Delivery System ( Opening and Closing the Retort)  Treatment Operator ( TO) Arsenic ( As) 16 (

)

( Target MOE 30) 0.3 (

)

( Target MOE 3) 467 ( Target MOE 30) 7 ( Target MOE 3) 16 (

)

( Target MOE 30) 0.3 (

)

( Target MOE 3) 4.1E 3 (

) 1.9E 4 (

)

Chromium ( Cr) NA NA 7 (

)

( Target MOE 100) 7 (

)

( Target MOE 100)   NA 1.8E 4 (

)

( 1) Applying Liquid Formulations at Pressure Treatment Plants using an Automatic/ Closed Delivery System ( Opening and Closing the Retort)  Treatment assistant ( TA) Arsenic ( As) 48 ( Target MOE 30) 0.8 ( Target MOE 3) 769 ( Target MOE 30) 12 ( Target MOE 3) 45 ( Target MOE 30) 0.7 ( Target MOE 3) 1.4E 3 (

) 1.2E 4 (

)

Chromium ( Cr) NA NA 7 (

)

( Target MOE 100) 7 (

)

( Target MOE 100)   NA 1.6E 4 (

)

Note: a). IA = HIARC concluded that the skin irritation and the skin allergenicity effects are the primary concern for Cr( VI) through the dermal exposure route. For the, risk concern of the dermal contact of Cr( VI) associated with worker scenarios should be addressed through precautionary labeling statements.

b). NA = Not Applicable. 18 Table 12 CCA Occupational Risk Assessment  Summary of Postapplication Exposure Scenarios Cells Marked with (

) Stand for the exposure Scenario Pose a Risk Concern Potential Receptor ( Receptor #) Chemical of Concern Non Carcinogenic Cancer Dermal Inhalation Inhalation Dermal Inhalation Short, and Intermediate term Long term Short, and Intermediateterm Long term Short, and Intermediateterm Long term ( 1) Loader Operator Arsenic ( As) 21 (

) 0.3 (

) 581 9 20 (

) 0.3 (

) 3.3E 3 (

) 1.5E 4 (

)

Chromium ( Cr) NA NA 6 (

) 6 (

)    ( c) 2.0E 4 (

)

( 2) Test Borer Arsenic ( As) 263 4 1471 24 223 4 2.5E 4 (

) 6.0E 5 Chromium ( Cr) NA NA NA NA    NA ( 3) Tram Setter Arsenic ( As) 8 (

) 0.1 (

) 195 3 8 (

) 0.1 (

) 8.4E 3 (

) 4.7E 4 (

)

Chromium ( Cr) NA NA 6 (

) 6 (

)    2.0E 4 (

)

( 4) Supervisor Arsenic ( As) 16 (

) 0.3 (

) 325 5 15 (

) 0.3 (

) 4.1E 3 (

) 2.8E 4 (

)

Chromium ( Cr) NA NA 6 6    2.0E 4 (

)

( 5) Tally Man Arsenic ( As) 18 0.3 (

) 1136 18 18 (

) 0.3 (

) 3.8E 4 (

) 8.0E 5 Chromium ( Cr) NA NA NA NA NA NA  NA ( 6) Stacker Operator Arsenic ( As) 38 0.6 (

) 1515 24 38 0.6 (

) 1.8E 3 (

) 6.0E 5 Chromium ( Cr) NA NA 6 (

) 6 (

)    1.6E 4 (

)

Note: a). Recommended Dermal and Inhalation MOE for Arsenic: short and intermediate term = 30; long term = 3;

Recommended Inhalation MOE for Chromium VI: Short, intermediate and long term = 100.

b). NA = Not Applicable.

c). HIARC concluded that the skin irritation and the skin allergenicity effects are the primary concern for Cr( VI) through the dermal exposure route. For the, risk concern of the dermal contact of Cr( VI) associated with worker scenarios should be addressed through precautionary labeling statements. 19 6.0 UNCERTAINTY ANALYSIS 6.1 Uncertainties and Deficiencies in Hazard Assessment There are uncertainties inherent in each hazard assessment procedure. However, there are some uncertainties specific to this risk assessment. Since no inhalation toxicity on studies are available for non cancer endpoints, oral toxicity endpoints have been selected for this risk assessment and will be discussed in this Section.

6.1.1 Using Human Data Setting the Short term and Intermediate term Incidental Oral and Dermal Exposures End Points The lowest observed adverse effect level ( LOAEL) selected for short and intermediate term dermal exposures for arsenic was 0.05 mg/ kg/ day was based on toxic effects including edema of the face; gastrointestinal, upper respiratory, skin, peripheral and neuropathy symptoms. The LOAEL comes from the work of Franzblau et al. ( 1989) and Mizuta et al. ( 1956) who examined oral exposure to individuals exposed during a reported poisoning incident involving the presence of arsenic [ probably calcium arsenate] contained in soy sauce. Both HIARC ( 2001) and SAP ( 2001) considered this is an appropriate toxicological endpoint and a margin of exposure of 30 from this LOAEL is recommended for non cancer health effects, this approach may either over or underestimate the risk. Although some panel members in the SAP ( 2001) suggested a target MOE of 10 should be enough for this risk assessment., a value of 30 has been selected.

6.1.2 Dermal Absorption In evaluating the exposure of inorganic arsenic through the dermal exposure route, 6.4% dermal absorption is used in the dermal risk assessment. The value of 6.4% dermal absorption was suggested by HIARC ( 2001) and was selected based on the use of non human primates exposure to inorganic arsenic in aqueous solution for derivation of this value and the fact that this was a well conducted study. It is observed in the study that a higher dose on the skin resulted in lower dermal absorption as noted above, but the data suggests sufficient variability in the absorption such that use of the 6.4% dermal absorption value is sufficiently but not overly conservative. The SAP ( 2001) was suggesting using dermal absorption value of 2 3% for dermal absorption of inorganic arsenic in the soil or wood surface residue. However, because only worker exposure scenarios are involved in this risk assessment, the dermal absorption value of 6.4% for arsenic in water was used in this risk assessment. Using of the dermal absorption value of 6.4% may overor underestimate the risk. 20 6.1.3 Arsenic Cancer Potency Factors The oral cancer potency factor of 3.67 per mg/ kg/ day is derived from the risk assessment associated with inorganic arsenic in drinking water. Following the EPA's presentation of the risk assessment in 2000, EPA asked the National Research Council ( NRC) to meet again to: ( 1) review EPA's characterization of potential human health risks from ingestion of inorganic arsenic in drinking water; ( 2) review the available data on the carcinogenic and non carcinogenic effects of inorganic arsenic; ( 3) review the data on the metabolism, kinetics and mechanism( s)/ mode( s) of action of inorganic arsenic; and ( 4) identify research needs to fill data gaps. In 2001 NRC published an update to the 1999 NRC report and concluded that ( 1). Arsenic induced bladder and lung cancers still should be the focus of arsenic related cancer risk assessment; ( 2) the southwestern Taiwan data are still the most appropriate for arsenic related cancer risk assessment; and ( 3) present modes of action data are not sufficient to depart from the default assumption of linearity. However, the 2001 NRC update made specific recommendations with respect to the overall cancer risk estimate. The Agency is currently considering these recommendations and their potential impact on the cancer potency estimate. Based on the Agency's considerations of these recommendations, the current proposed cancer potency number may change in the final version of this risk assessment.

6.2 Uncertainties and Deficiencies in Exposure Assessment 6.2.1 Data Gaps and Limitations In the course of the occupational exposure chapter development for this RED, chemical specific handler data submitted by industry and identified from pertinent literature sources were reviewed for use in developing exposure estimates for worker populations. Certain studies are presented in this section as an overview of the available data, however only data from the ACC Worker Exposure Study ( MRID 455021 01) ( ACC, 2001) were used in developing appropriate occupational scenarios for wood treatment plant workers involved with pressure treatments. These data were deemed the most appropriate.

Hexavalent chromium inhalation exposure data were not available for postapplication exposure for scenarios for Tram setter ( TS) and Tally Man ( TM).

7.0 CONCLUSIONS In conclusion, all the scenarios for non carcinogenic and/ or carcinogenic risks are summarized in Tables 11 and 12 7.1 Primary Handler The results of the handler exposure and risk assessment indicate that short, intermediate, and long term risks for dermal and inhalation exposures exceed the level of concern for arsenic for some of the handler scenarios. For arsenic, a margin of exposure ( MOE) of 30 or more for shortand intermediate term dermal risk is considered not to be of concern and an MOE of 3 or more is considered not to be of concern for long term risks. The calculated MOE for both treatment operator ( TO) and treatment assistant ( TA) for dermal and combined ( dermal + inhalation) 21 exposure of arsenic are all below the target MOE for both short, intermediate and long term scenarios. Therefore, the results of the risk assessment indicate that the exposure of arsenic through dermal route posed risks of concern to primary handlers.

The MOEs for the inhalation exposure scenarios presented in the risk assessment do not exceed the Agency's level of concern for both short, and intermediate term and long term inhalation exposures to arsenic ( i. e., MOEs < 30) . Therefore, for inhalation only, exposure through arsenic only does not pose risk of concern to primary handler scenarios. However, the combined risk ( inhalation + dermal) still pose risk concern for both TA and TO.

The MOEs for the inhalation exposure scenarios presented in the risk assessment exceed the Agency's level of concern long term inhalation exposures to hexavalent chromium ( i. e. MOEs < 100) for both TO and TA, Exposure to hexavalent chromium pose short term, intermediateterm and long term exposure health concern. However, to chrome pose unacceptable risk to both TA and TO.

In addition, dermal and inhalation exposure to arsenic pose a cancer risk concern for all primary handler scenarios ( risk exceed the level of concern = 1E 04). Inhalation exposure to chrome also pose a cancer risk concern to both TA and TO. It is important to know that all inhalation monitoring samples were below the limit of detection( i. e., cancer risks are based on ½ LOD). The analytical technique used to determine the amount of Cr+ 6 in the sample was inadequate.

7.2 Postapplication Many of the MOEs for the dermal exposure scenarios presented in the risk assessment exceed the Agency's level of concern for short, intermediate and long term dermal exposures to arsenic.

The risks for the inhalation exposure scenarios presented in the risk assessment do exceed the Agency's level of concern for short, and intermediate inhalation exposures to arsenic ( i. e., MOEs< 100) based on the toxicological information for arsenic.

The risks for the inhalation exposure scenarios presented in the risk assessment exceed the Agency's level of concern for short, intermediate and long term inhalation exposures to chromium ( i. e. MOEs < 30) for some of the postapplication scenarios based on the toxicological information for Chromium ( VI).

The cancer risks assessment associated with dermal exposure to arsenic pose risk concern for all postapplication worker scenarios. Inhalation exposure would pose cancer risk concern for Loader Operator , Tram Setter, Supervisor and Staker Operator, but not to Test Borer and Tally man. All inhalation monitoring samples were below the limit of detection, but because the analytical technique used to determine the amount of Cr+ 6 in the sample was inadequate. In the cancer risk calculation, by using ½ LOD, inhalation exposure pose cancer risk concerns for all postapplication scenarios. 22 8.0 REFERENCES American Chemistry Council ( ACC), 2001. Arsenical Wood Preservatives Task Force. Assessment of Potential Inhalation and Dermal Exposure Associated with Pressure Treatment of Wood with Arsenical Products. MRID 455021 01. September 24, 2001.

National Research Council. 1999. Arsenic in Drinking Water. National Academy Press, NW.

PHED Surrogate Exposure Guide. 1998. Estimates of Worker Exposure from the Pesticide Handler Exposure Database. Version 1.1. August 1998.

U. S. EPA, 1984. " Wood Preservative Pesticides: Creosote, Pentachlorophenol, Inorganic Arsenicals. Position Document 4." Registration Division. Office of Pesticides and Toxic Substances. Washington, D. C. July, 1984.

U. S. EPA, 1989. Risk Assessment Guidance for Superfund. Volume I. Human Health Evaluation Manual ( Part A). Interim Final. Office of Emergency and Remedial Response. Washington, D. C. EPA/ 540/ 1 89/ 002.

U. S. EPA, 1997. Exposure Factors Handbook. Volume I III. Office of Research and Development. Washington, D. C. EPA/ 600/ P 05/ 002Fa.

U. S. EPA, 1998. Series 875 Occupational and Residential Exposure Test Guidelines, Group BPostapplication Exposure Monitoring Test Guidelines, Version 5.4. Office of Pesticide Programs, Health Effects Division. February 1998.

U. S. EPA, 2002. Inorganic Arsenic  Report of the Hazard Identification Assessment Review Committee; Inorganic Chromium  Report of the Hazard Identification Assessment Review Committee. J. Chen, S. Malish, and T. McMahon. April 15, 2002.

U. S. EPA, 2000. National Primary Drinking water Regulations; Arsenic and Clarifications to Regulations; Arsenic and Clarifications to Compliance and New Source Contaminants Monitoring Proposed Rule. 40 CFR Parts 141 and 142.


[Federal Register: April 25, 2008 (Volume 73, Number 81)]
[Notices]
[Page 22372-22373]
[DOCID:fr25ap08-59]

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ENVIRONMENTAL PROTECTION AGENCY

[FRL-8558-2; Docket ID No. EPA-HQ-ORD-2008-0245]

Draft Toxicological Review of Ethylene Glycol mono-Butyl Ether
(EGBE): In Support of the Summary Information in the Integrated Risk
Information System (IRIS)

AGENCY: Environmental Protection Agency (EPA).

ACTION: Notice of public comment period.

-----------------------------------------------------------------------

SUMMARY: The EPA is announcing a public comment period for the external
review draft document entitled, ``Toxicological Review of Ethylene
Glycol mono-Butyl Ether (EGBE): In Support of Summary Information on
the Integrated Risk Information System (IRIS)'' (EPA/635/R-08/006A).
EPA intends to consider comments and recommendations from the public
and the expert panel meeting, which will be scheduled at a later date
and announced in the Federal Register, when EPA finalizes the draft
document. The public comment period will provide opportunities for all
interested parties to comment on the document. EPA intends to forward
public comments, submitted in accordance with this notice, to the
external peer-review panel prior to the workshop for their
consideration.
    EPA is releasing this draft document solely for the purpose of pre-
dissemination public review under applicable information quality
guidelines. This document has not been formally disseminated by EPA. It
does not represent and should not be

construed to represent any Agency policy or determination.
    The draft document is available via the Internet on NCEA's home
page under the Recent Additions and the Data and Publications menus at
http://www.epa.gov/ncea. When finalizing the draft document, EPA
intends to consider any public comments that EPA receives in accordance
with this notice.

DATES: The public comment period begins April 25, 2008, and ends June
24, 2008. Technical comments should be in writing and must be received
by EPA by June 24, 2008. EPA intends to submit comments from the public
received by this date for consideration by the external peer-review
panel.

ADDRESSES: The draft ``Toxicological Review of Ethylene Glycol mono-
Butyl Ether (EGBE): In Support of the Summary Information on the
Integrated Risk Information System (IRIS)'' is available via the
Internet on the National Center for Environmental Assessment's (NCEA)
home page under the Recent Additions and the Data and Publications
menus at http://www.epa.gov/ncea. A limited number of paper copies are
available by contacting the Information Management Team, NCEA;
telephone:<PHONE_NUMBER>; facsimile:<PHONE_NUMBER>. If you are requesting
a paper copy, please provide your name, mailing address, and the
document title.
    Comments may be submitted electronically via www.regulations.gov,
by mail, by facsimile, or by hand delivery/courier. Please follow the
detailed instructions as provided in the SUPPLEMENTARY INFORMATION
section of this notice.

FOR FURTHER INFORMATION CONTACT: For information on the public comment
period, contact the Office of Environmental Information Docket;
telephone:<PHONE_NUMBER>; facsimile:<PHONE_NUMBER>; or e-mail:
<EMAIL_ADDRESS>    If you have questions about the document, contact, Angela Howard,
Chemical Manager, National Center for Environmental Assessment;
telephone:<PHONE_NUMBER>; facsimile:<PHONE_NUMBER>; e-mail:
<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION:

I. Summary of Information about the Integrated Risk Information System
(IRIS)

    IRIS is a database that contains potential adverse human health
effects information that may result from chronic (or lifetime) exposure
to specific chemical substances found in the environment. The database
(available on the Internet at http://www.epa.gov/iris) contains
qualitative and quantitative health effects information for more than
500 chemical substances that may be used to support the first two steps
(hazard identification and dose-response evaluation) of a risk
assessment process. When supported by available data, the database
provides oral reference doses (RfDs) and inhalation reference
concentrations (RfCs) for chronic health effects, and oral slope
factors and inhalation unit risks for carcinogenic effects. Combined
with specific exposure information, government and private entities can
use IRIS data to help characterize public health risks of chemical
substances in a site-specific situation and thereby support risk
management decisions designed to protect public health.

II. How to Submit Technical Comments to the Docket at http://
www.regulations.gov

    Submit your comments, identified by Docket ID No. EPA-HQ-ORD-2008-
0245 by one of the following methods:
     http://www.regulations.gov: Follow the on-line
instructions for submitting comments.
     E-mail<EMAIL_ADDRESS>     Fax:<PHONE_NUMBER>.
     Mail: Office of Environmental Information (OEI) Docket
(Mail Code: 2822T), U.S. Environmental Protection Agency, 1200
Pennsylvania Ave., NW., Washington, DC 20460. The phone number is 202-
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     Hand Delivery: The OEI Docket is located in the EPA
Headquarters Docket Center, EPA West Building, Room 3334, 1301
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    If you provide comments by mail or hand delivery, please submit one
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    Instructions: Direct your comments to Docket ID No. EPA-HQ-ORD-
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EPA's policy to include all comments it receives in the public docket
without change and to make the comments available online at http://
www.regulations.gov, including any personal information provided,
unless a comment includes information claimed to be Confidential
Business Information (CBI) or other information whose disclosure is
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and included as part of the comment that is placed in the public docket
and made available on the Internet. If you submit an electronic
comment, EPA recommends that you include your name and other contact
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and cannot contact you for clarification, EPA may not be able to
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EPA Docket Center homepage at http://www.epa.gov/epahome/dockets.htm.
    Docket: All documents in the docket are listed in the http://
www.regulations.gov index. Although listed in the index, some
information is not publicly available, e.g., CBI or other information
whose disclosure is restricted by statute. Certain other material, such
as copyrighted material, will be publicly available only in hard copy.
Publicly available docket materials are available either electronically
in http://www.regulations.gov or in hard copy at the OEI Docket in the
EPA Headquarters Docket Center.

    Dated: April 16, 2008.
Peter W. Preuss,
Director, National Center for Environmental Assessment.
[FR Doc. E8-9088 Filed 4-24-08; 8:45 am]

BILLING CODE 6560-50-P


[Federal Register Volume 78, Number 175 (Tuesday, September 10, 2013)]
[Notices]
[Page 55250]
[FR Doc No: 2013-21959]

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DEPARTMENT OF ENERGY

Federal Energy Regulatory Commission

[Docket No. ER13-2304-000]

TEC Energy Inc.; Supplemental Notice That Initial Market-Based
Rate Filing Includes Request for Blanket Section 204 Authorization

    This is a supplemental notice in the above-referenced proceeding,
of TEC Energy Inc.'s application for market-based rate authority, with
an accompanying rate schedule, noting that such application includes a
request for blanket authorization, under 18 CFR part 34, of future
issuances of securities and assumptions of liability.
    Any person desiring to intervene or to protest should file with the
Federal Energy Regulatory Commission, 888 First Street, NE.,
Washington, DC 20426, in accordance with Rules 211 and 214 of the
Commission's Rules of Practice and Procedure (18 CFR 385.211 and
385.214). Anyone filing a motion to intervene or protest must serve a
copy of that document on the Applicant.
    Notice is hereby given that the deadline for filing protests with
regard to the applicant's request for blanket authorization, under 18
CFR part 34, of future issuances of securities and assumptions of
liability is September 23, 2013.
    The Commission encourages electronic submission of protests and
interventions in lieu of paper, using the FERC Online links at http://www.ferc.gov. To facilitate electronic service, persons with Internet
access who will eFile a document and/or be listed as a contact for an
intervenor must create and validate an eRegistration account using the
eRegistration link. Select the eFiling link to log on and submit the
intervention or protests.
    Persons unable to file electronically should submit an original and
5 copies of the intervention or protest to the Federal Energy
Regulatory Commission, 888 First Street NE., Washington, DC 20426.
    The filings in the above-referenced proceeding(s) are accessible in
the Commission's eLibrary system by clicking on the appropriate link in
the above list. They are also available for review in the Commission's
Public Reference Room in Washington, DC. There is an eSubscription link
on the Web site that enables subscribers to receive email notification
when a document is added to a subscribed docket(s). For assistance with
any FERC Online service, please email<EMAIL_ADDRESS>or
call<PHONE_NUMBER> (toll free). For TTY, call<PHONE_NUMBER>.

    Dated: September 3, 2013
Nathaniel J. Davis, Sr.,
Deputy Secretary.
[FR Doc. 2013-21959 Filed 9-9-13; 8:45 am]
BILLING CODE 6717-01-P


[Federal Register Volume 77, Number 43 (Monday, March 5, 2012)]
[Rules and Regulations]
[Page 12991]
[FR Doc No: 2012-5290]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2011-1420; Directorate Identifier 2011-CE-035-AD;
Amendment 39-16905; AD 2011-27-04]
RIN 2120-AA64

Airworthiness Directives; Hawker Beechcraft Corporation Airplanes
Equipped With a Certain Supplemental Type Certificate (STC)

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Final rule; correction.

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SUMMARY: The FAA is correcting an airworthiness directive (AD) that
published in the Federal Register. That AD applies to all Hawker
Beechcraft Corporation Models 95-C55, D55, E55, 58, and 58A airplanes
equipped with a certain STC. The description of the affected STCs in
the first sentence of the SUPPLEMENTARY INFORMATION, Discussion
section, is incorrect. This document corrects that error. In all other
respects, the original document remains the same.

DATES: This final rule is effective March 5, 2012. The effective date
for AD 2011-27-04 (76 FR 81790, December 29, 2011) remains December 29,
2011.

ADDRESSES: You may examine the AD docket on the Internet at http://www.regulations.gov; or in person at the Docket Management Facility
between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays. The AD docket contains this AD, the regulatory evaluation,
any comments received, and other information. The address for the
Docket Office (phone:<PHONE_NUMBER>) is Document Management Facility,
U.S. Department of Transportation, Docket Operations, M-30, West
Building Ground Floor, Room W12-140, 1200 New Jersey Avenue SE.,
Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: Eric B. Potter, Aerospace Engineer,
Atlanta Aircraft Certification Office, FAA, 1701 Columbia Avenue,
College Park, Georgia 30337; phone:<PHONE_NUMBER>; fax: (404) 474-
5606; email<EMAIL_ADDRESS>
SUPPLEMENTARY INFORMATION: Airworthiness Directive 2011-27-04,
amendment 39-16905 (76 FR 81790, December 29, 2011), currently requires
assuring the airspeed indicator(s) and/or airspeed limitations
placard(s) have the correct minimum control speed (VMC)
markings for all Hawker Beechcraft Corporation Models 95-C55, D55, E55,
58, and 58A airplanes equipped with a certain STC.
    As published, the description of the affected STCs in the first
sentence of the SUPPLEMENTARY INFORMATION, Discussion section, is
incorrect.
    No other part of the preamble or regulatory information has been
changed; therefore, only the changed portion of the preamble to the
final rule is being published in the Federal Register.
    The effective date of this AD remains December 29, 2011.

Correction of Non-Regulatory Text

    In the Federal Register of December 29, 2011, AD 2011-27-04;
Amendment 39-16905 is corrected as follows:
    On page 81790, in the third column, on line 2 under the heading
SUPPLEMENTARY INFORMATION, Discussion, correct ``, we found that STC
SA1762SO (installation of vortex generators) and STC SA4016NM (Foxstar
Baron modification of winglets and different engines and propellers)
were installed.'' to read ``, we found that STC SA1762SO (Foxstar Baron
modification of winglets and different engines and propellers) and STC
SA4016NM (installation of vortex generators) were installed.''

    Issued in Kansas City, Missouri, on February 23, 2012.
John Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 2012-5290 Filed 3-2-12; 8:45 am]
BILLING CODE 4910-13-P


Memorandum
      To:	316(b) Record
      From:	316(b) Team, Engineering and Analysis Division, U.S. Environmental Protection Agency
      Date:	May 15, 2014
      Re:	Applicability Threshold of the Existing Facilities Rule
The cost information presented below is for the existing unit provision of the final rule, to facilitate comparison with the propose rule, where existing and new unit costs were not added together and reported as such. When costs of the new unit provision are added, the total cost of the final rule becomes $275 million. See the Technical Development Document (TDD) (DCN 12-0005) and the Economic Analysis (EA) (DCN 12-0002) for detailed analyses.
1. There are substantial environmental benefits that result from having the rule apply to facilities below 50 mgd.
    Facilities with DIF below 50 mgd are twice as likely to have no controls in place for impingement or entrainment as are those facilities with DIF greater than 50 mgd.
    A higher threshold ignores the site-specific impacts of these lower flow intakes and forgoes the site-specific benefits of reducing the impacts, including non-monetized benefits that are not accounted for in the benefits analysis because they are difficult to monetize (e.g., ecosystem benefits).
    More than 63 percent of facilities with DIF below 50 mgd are co-located with other intakes on fresh water rivers; cumulative impacts are not accounted for in the quantified or monetized benefits analysis for this rule. (See TDD Chapter 5)
    At least 19 percent of all facilities below 50 mgd and located on rivers (38 known facilities with data) withdraw a significant volume of the source water (DIF is more than 5 percent of the mean annual flow of the fresh water sources on which they are located). (See TDD Chapter 5) Using the same analysis methods applied in TDD Chapter 5, EPA also determined that 14 percent of the 110 known facilities below 20 mgd with data located on rivers have an intake designed to withdraw more than 5 percent of the mean annual flow of the source water.

1. The rule is not costly to lower flow facilities and there is no appreciable difference in the cost effectiveness of the rule for facilities that are 2 mgd to less than 50 mgd and those 50 mgd and above.
    The cost effectiveness of the rule with a threshold of 2 mgd is $0.418 per age-one equivalent loss (A1E) and at a threshold of 50 mgd, the cost effectiveness is $0.410 per A1E for existing units.  See Table 1.
    Of the total $272 million cost of the rule for existing units at 1,065 facilities, $20 million (7 percent) will be incurred by the 471 facilities below 50 mgd, and $252 million (93 percent) will be incurred by the 593 facilities at or above 50 mgd. In other words, the 44 percent of facilities below 50 mgd are estimated to incur only 7 percent of the costs, while 56 percent of the facilities at or above 50 mgd are estimated to incur 93 percent of the costs (for existing units).
    The total cost of the rule with a threshold of 2 mgd is negligible for the electric power industry, accounting for less than 0.1 percent of annual electricity sector revenues, which exceed $126 billion.
    Costs for lower flow facilities are so small that the average annual household utility bill would not measurably decrease by changing the threshold from 2 to 50 mgd.

1. A higher threshold provides no significant small business advantage.
      *       If the goal is to protect small manufacturing businesses, a low flow threshold of 50 mgd is far too blunt a tool.  See Table 2.
              o       Small businesses account for only 17% of facilities between 2 and 50 mgd (79 of 471).  Small businesses account for 10% of facilities above 50 mgd (57 of 593); of these, just 6 are manufacturers.  Thus, most of the small manufacturers (61 of 67) are below 50 mgd.
              o       The converse - that the 471 firms between 2 and 50 mgd are mostly small manufacturers (61) - is not true.  The most prevalent type of firm under 50 mgd is a large manufacturer (313), the second most prevalent is a large electric generator (79), followed by small manufacturers (61) and small generators (18).
      *       Even the Small Business Panel from the Phase III rulemaking (manufacturers and low flow electric generators) did not select a 50 mgd threshold.
              o       The panel found that "an effective way to substantially reduce potential impacts on small businesses would be to set an applicability threshold of 20 mgd" and recommended analyzing thresholds between 20 and 50 mgd.
              o       At that time, EPA was considering requirements that covered entrainment as well as impingement, making for a more expensive rule.
      *       For the final rule, EPA finds that no small entities that own manufacturers facilities have a cost-to-revenue ratio of 3 percent, and only three to four small entities have a cost-to-revenue ratio exceeding 1 percent; further, this analysis assumes zero cost pass-through to the consumer. The results of EPA's analysis of the impacts on small businesses lead the agency to certify no significant economic impacts on a substantial number of small entities (no SISNOSE).

2. Rule costs are already less than either of EPA's preferred options at proposal; Proposal Option 1 and the least costly, Proposal Option 4.
    The final rule`s total cost of $272 million (existing units) is $127 million less than EPA's preferred option at proposal (Proposal Option 1) because of added flexibilities and elimination of a single numeric Impingement Mortality performance standard.  The final rule also costs $55 million less than Proposal Option 4, which included a 50 mgd threshold at a total cost of $327 million, for existing units (see Table 13-4 of the Economic and Benefits Analysis for Proposed Section 316(b) Existing Facilities Rule (DCN 10-0002)).

1. Even if lower flow facilities were exempted from the rule's impingement requirements, they would still be subject to BPJ permitting for 316(b) requirements.
    In a recent review of permits (DCN 12-2932), EPA found more frequent use of BPJ permitting than in an earlier review (DCN 10-6623). Permits in 8 of the 18 States EPA reviewed more recently contain no 316(b) requirements. However, permits in the remaining 10 States do include 316(b) requirements with varying levels of information submission requirements and associated administrative burden and cost.
    EPA did not account for the costs that permitting authorities and facilities otherwise incur for BPJ-based permit activity, as currently occurs in the absence of a national 316(b) regulation. To the extent that permitting authorities and facilities are incurring these costs, those costs should be analyzed as an avoided cost of the final rule.  Any baseline BPJ costs imply that the costs reported in the Economic Analysis (EA) of the regulation are overstated.
       EPA's cost estimates do not account for BPJ costs, following EPA's 2010 Guidelines for Preparing Economic Analyses.  The guidance there is to estimate the costs of the rule (or options analyzed) as the difference between costs in the world with the rule (or option) and the world without the rule (or option). When analyzing an option that is BPJ for facilities below 50 mgd, both the world with the option and the world without the option include BPJ permitting.  Therefore, the difference in costs is zero.
    Exempting lower-flow facilities would not mean zero permitting or compliance costs because these facilities would be issued permits with BPJ-based 316(b) requirements. For example, based on the Phase II ICR ($395k to $679k per facility initial application, $7k annual reporting and monitoring), submission of basic characterization studies and permit application materials upon which site-specific impingement requirements would be based, cost the 531 facilities with a DIF less than 50 mgd from $59.8 million to $99.3 million per year in aggregate ($2012).
    Raising the threshold would increase the number of individual BPJ permits, which can increase uncertainty, complexity and the amount of time required for permitting. The burden on State permitting authorities would also be higher for BPJ-based permits compared to permits developed under national requirements.
    Realizing the $23 million cost "savings" associated with a 50 mgd threshold is predicated on the outcome of BPJ permitting being "no additional controls" at all these facilities, even though the rule contains specific requirements for facilities above 50 mgd that could be easily applied.

1. A 2 mgd threshold was adopted in Phase I.
    The Phase I 316(b) New Facilities rule states, "All cooling water intake flow results in the potential for impingement and Entrainment," and, "The 2 MGD threshold was chosen because this threshold addresses 99.7 percent of the total flow and 62 percent of all in-scope facilities. EPA estimates that 58 percent of the manufacturers, 70 percent of the non-utilities, and 100 percent of the utilities will be regulated at the 2 MGD threshold."

1. Small flow facilities already have closed-cycle.
    Most facilities are in the below 50 mgd category because they already have closed-cycle cooling. The permit application process is highly streamlined for closed-cycle.
    51 percent of facilities with DIF below 50 mgd have closed-cycle cooling.
    30 percent of manufacturers with DIF below 50 mgd have closed-cycle cooling.

            Table 1  -  Comparison of 2 versus 50 mgd Thresholds[1]

Greater than 2 mgd
Greater than or equal to 50 mgd
Number of facilities
1,065
593
Number of facilities owned by small entities[5]
136
57
DIF as percent of total DIF[2]
100% (408,286 mgd)
97%
AIF as percent of total AIF[3]
100% (237,832 mgd)
98%
Total Option Costs (existing units)
$272 million
$252 million
Quantified benefits[4]
652 million A1E
614 million A1E
Cost effectiveness (existing units)
$0.418A1E
$0.410/A1E

[1]The numbers presented in this table are aggregate national numbers and do not indicate the extent of site-specific impacts.
[2]DIF (design intake flow) -- the maximum instantaneous rate of flow of water the cooling water intake system is capable of withdrawing from a source waterbody.
[3] AIF (actual intake flow) -- the average volume of water withdrawn on an annual basis by the cooling water intake structures over the past three years.
[4]A1E (age-one equivalent losses) -- the number of individual organisms of different ages impinged and entrained by facility intakes, standardized to equivalent numbers of one-year-old fish.
5 Small entity as defined under the Small Business Administration size standards. See Chapter 10 of the EA for more details.

Table 2  -  Counts of All Facilities by DIF Flow and Parent Entity Size[1][,2,3]

                             Size of Parent Entity
                              Electric Generators
                                 Manufacturers
                                     Total
                DIF Greater than Two MGD but Less than 50 MGD
                                     Small
                                      18
                                      61
                                      79
                                     Large
                                      79
                                     313
                                     392
                                     Total
                                      97
                                     374
                                     471
                           DIF of 50 MGD or Greater
                                     Small
                                      51
                                      6
                                      57
                                     Large
                                      396
                                     141
                                     537
                                     Total
                                      447
                                     146
                                     593
                           DIF Greater than Two MGD
                                     Small
                                      69
                                      67
                                     136
                                     Large
                                      475
                                     454
                                     929
                                     Total
                                      544
                                     521
                                    1,065
1 This table reports counts of facilities owned by entities that EPA classified either small or large based on Small Business Administration (SBA) entity size criteria.
[2] DIF (design intake flow) -- the maximum instantaneous rate of flow of water the cooling water intake system is capable of withdrawing from a source waterbody.
[3] Individual values may not sum to totals due to independent rounding.