PAGE INTENTIONALLY LEFT BLANK William C. Herz Director of Scientific Programs M E M O R A N D U M TO: Product Testing Recipient FROM: William C. Herz, Director, Scientific Programs SUBJECT: Potassium Nitrate Product Testing Dossier DATE: March 15, 2003 It is with great pleasure that The Fertilizer Institute ( TFI) announces the completion and distribution of the final product testing dossier for Potassium Nitrate ( CAS # 7757 79 1).

As you are aware, TFI sponsored this four   year program to develop and summarize screeninglevel hazard information for high production volume ( HPV) chemicals. The data elements generated represent a broad overview of human health and ecological parameters. These include a physical  chemical characterization, environmental fate, mammalian toxicity and ecotoxicity. A health and environmental safety data summary dossier was prepared for each of the 23 materials. It summarizes the available literature data, new testing data, category description and read across data as well as provides a conclusion regarding the inherent hazards of the material.

Upon receipt of this data a 90 calendar day regulatory trigger starts within which you must update your material safety data sheets ( MS DS). Upon first product shipment you must also notify your distributors and employers once the MS DS has been updated. These regulatory requirements are detailed in 29 CFR 1910.1200( g)( 5) and 29 CFR 1910.1200( g)( 6)( i). The requirements are found in the Occupational Safety and Health Administration " Hazard Communication Standard" ( 29 CFR 1910.1200).

Please note that by receipt of this data; you agree not to distribute or sell this data beyond your own company. PAGE INTENTIONALLY LEFT BLANK POTASSIUM NITRATE CAS # 7757 79 1 Prepared for:

THE FERTILIZER INSTITUTE January 27, 2003 THE WEINBERG GROUP INC. 1220 Nineteenth St, NW, Suite 300 Washington, DC 20036 2400 e mail science@ weinberggroup. com WASHINGTON NEW YORK SAN FRANCISCO BRUSSELS PARIS Potassium Nitrate CAS # 7757 79 1 PAGE INTENTIONALLY LEFT BLANK Potassium Nitrate CAS # 7757 79 1 TABLE OF CONTENTS Page EXECUTIVE OVERVIEW................................................................................................... 1 SIDS DATA PROFILE.......................................................................................................... 7 SIDS DATA SUMMARY..................................................................................................... 8 1. GENERAL INFORMATION.................................................................................... 10 2. PHYSICAL CHEMICAL DATA.............................................................................. 13 3. ENVIRONMENTAL FATE AND PATHWAYS..................................................... 17 4. ECOTOXICITY......................................................................................................... 20 5. TOXICITY................................................................................................................. 25 6. REFERENCES .......................................................................................................... 36 APPENDICES Appendix A SIDS Data Availability Summary Appendix B SIDS Data Summaries for the Nitrate Compounds Category: Ammonium Nitrate, Nitrogen Solutions ( primarily Urea Ammonia Nitrogen [ UAN]), Potassium Nitrate, Potassium Sodium Nitrate, and Sodium Nitrate ACRONYMS AND ABBREVIATIONS BCF Bioconcentration Factor bw Body Weight DAP Diammonium Phosphate DOT Department of Transportation FDA U. S. Food and Drug Administration g/ L Grams per Liter GLP Good Laboratory Practices GTSP Granular Triple Super Phosphate g/ mL Grams per Milliliter HSDB Hazardous Substance Data Bank IPCS International Programme for Chemical Safety KNO3 Potassium Nitrate Koc Organic Carbon Partition Coefficient Kow Octanol/ Water Partition Coefficient LC50 Median Lethal Concentration LD50 Median Lethal Dose LOAEL Lowest Observable Adverse Effect Level LOEC Lowest Observable Effect Concentration LOEL Lowest Observable Effect Level M Molar Potassium Nitrate CAS # 7757 79 1 MAP Monoammonium Phosphate mg/ kg Milligrams per Kilogram mg/ kg/ day Milligrams per Kilogram per Day mg/ L Milligrams per Liter MHb Methyl Hemoglobin mm Hg Millimeters of Mercury mmol/ L Millimoles per Liter NaNo3 Sodium Nitrate NFPA National Fire Prevention Association ( NH4) 2NO3 Ammonium Nitrate NIOSH National Institute for Occupational Safety and Health NO3 Nitrate NOAEL No Observable Adverse Effect Level NOEC No Observable Effect Concentration NOEL No Observable Effect Level OECD Organisation for Economic Co operation and Development Pa Pascal ppm Parts per Million SCAS Semi Continuous Activated Sludge SIDS Screening Information Data Set SSP Single Super Phosphate TLm Median Toxicity Level TLV Threshold Limit Value TFI The Fertilizer Institute UAN Urea Ammonia Nitrogen 1 Potassium Nitrate CAS # 7757 79 1 EXECUTIVE OVERVIEW I. Introduction The Fertilizer Institute, on behalf of its member companies, initiated a Product Testing Project to collect, review, summarize, and where necessary develop additional health and environmental safety data for 23 of its high production volume inorganic fertilizer materials. These data and summaries provide valuable information that can be used to update Material Safety Data Sheets, answer customers' questions, and support product stewardship efforts. The chemical industry is also participating in a voluntary program of comparable scope for high production volume organic chemicals. 1 The 23 fertilizer materials were divided into five categories ( i. e., ammonia compounds, nitrate compounds, phosphate compounds, salts and acids) based on their primary constituents as shown in Table 1. The use of categories is a recognized and accepted method that allows health and environmental safety data from one chemical in the category to be used to represent one or more other related chemicals in the category ( USEPA 1999). The key is to find similar, or at least predictable, patterns and trends among the chemicals in a category. In this way, data can be pooled, resources are optimized, and fewer animals are used in testing, all without losing the ability to evaluate the hazards and safety of the individual chemicals. Note that some of the materials fall into more than one category ( e. g., diammonium phosphate [ DAP] is in both the phosphate and ammonia categories).

Searches were conducted using on line databases, standard reference texts, and other published sources for toxicity, ecotoxicity, environmental fate, and physical chemical properties. The collected data were reviewed for quality and acceptability and then summarized according to the Organization for Economic Cooperation and Development ( OECD) Screening Information Data Set ( SIDS) dossier format ( OECD 1997). The OECD countries ( including the United States) have agreed on a set of tests and on types of data that are generally necessary to characterize the chemical behavior and potential hazards of chemicals released into the environment. The OECD SIDS dossier was chosen as a standard format for the TFI Product Testing Project in order that it would be scientifically defensible, broadly applicable and easily understandable to a wide range of stakeholders.

The following sections of this Executive Overview provide the rationale for development of the Nitrate Compounds category ( Section II); a synopsis of the available data related to the physicalchemical properties, environmental fate, ecotoxicity and toxicity of the nitrate compounds in this category ( Section III); and a conclusion regarding the adequacy of the data to sufficiently characterize the category and the need for additional testing ( Section IV).

The data for potassium nitrate are summarized in the Chemical Profile and Data Summary tables. Because the evaluation of data adequacy relies on a category approach, the Data Summary table references Appendix B when data are available for one or more of the other materials in the category for those data elements where no potassium nitrate data are available. Appendix B provides a summary of the data for all of the nitrate compounds in the category. The individual 1 HPV Chemical Challenge Program; USEPA 1999 ( http:// www. epa. gov/ opptintr/ chemrtk/ volchall. htm) 2 Potassium Nitrate CAS # 7757 79 1 studies for potassium nitrate itself are presented in subsequent pages of this document. Separate data summary documents are available for each of the nitrate compounds in the category.

II. Rationale for the Nitrate Compounds Category The nitrate compounds category for fertilizer materials includes ammonium nitrate, nitrogen solutions ( primarily Urea Ammonia Nitrogen [ UAN]), potassium nitrate, sodium nitrate, and potassium sodium nitrate. These compounds are structurally similar. In solution these compounds all dissociate into a common nitrate ion:

To this base, the compounds vary according to the simple cation present ( i. e., K+, Na+, NH4 +). The six compounds have similar and generally predictable patterns of behavior in the environment as well as toxicological properties. Nitrate itself is less toxicologically important than is nitrite. Nitrate is reduced to nitrite by the enzyme nitrate reductase which is found in plants, certain bacterial species, and mammalian gastric tissues ( Owens and Dubeski 1989). After ingestion nitrates are reduced to nitrites by bacteria in the lower intestine of the adult ( L'hirondel and L'hirondel 1998). In babies, it is this nitrite that can lead to a condition called methemoglobinemia (" blue baby syndrome") ( Burden 1961).

In addition to methemoglobinemia, some evidence indicates a possible formation of N nitroso compounds in foods and in tissues that contain excess nitrates/ nitrites ( Chow et al. 1980). Nnitroso compounds ( e. g., nitrosamines) are known to be potent mutagens/ carcinogens ( Lijinksy and Epstein 1970; Magee and Barnes 1967). However, the quantities of nitrosamines formed in mammals from nitrates in food are negligible and all of the epidemiological studies published since 1985 concluded that there is no positive correlation between nitrate intakes and the incidence of cancer ( Al Dabbagh et al. 1986; Forman et al. 1985; Leclerc et al. 1991; Lijinsky 1989; Lijinksy and Epstein 1970; Magee and Barnes 1967). In fact, some evidence suggests that nitrates in foods may actually play an anti carcinogenic role ( Lijinsky 1989).

In aquatic systems, the toxicity of the various nitrate materials is at least partially related to the cationic composition of the solution, although the available data suggest that aquatic toxicity is not a major concern ( Rubin and Elmaraghy 1977).

In terrestrial systems, nitrate absorbed by plants is reduced to nitrite by the enzyme nitrate reductase ( Owens and Dubeski 1989). The nitrite will be further reduced only when photosynthesis and carbohydrate synthesis are active ( Owens and Dubeski 1989). Under drought conditions, frost and shading, or deficiencies of other nutrients, each of which reduce photosynthesis and biosynthesis of protein, nitrate continues to be absorbed and may accumulate in plant tissue ( Owens and Dubeski 1989). Under most conditions, however, the nitrate ion will leach into the soil pore water and become indistinguishable from the natural nitrate already present. O N'

O O 3 Potassium Nitrate CAS # 7757 79 1 III. Summary of Data Available for the Nitrate Compounds Category Physical Chemical Data The density of nitrate compounds varies from 0.75 2.109 g/ mL. All nitrate compounds are highly soluble in water with solubility ranging from 357 1,920 g/ L at 20 25 ° C. Although few vapor pressure values are available, based on the fact that these compounds are solids, it may be concluded that they have low volatility. Very low octanol/ water partitioning coefficients indicate a low bioaccumulation potential.

Environmental Fate and Pathway Nitrate compounds biodegrade in the environment under certain conditions. Their high solubility and expected low volatility suggest that they are present mostly in aqueous solutions. While the cation may bind to clay particles in the soil, the nitrate anion may show significant leaching to ground water. Nitrate is subject to plant uptake and loss from the ecosystem in runoff waters or by denitrification.

Ecotoxicity The acute 96 hour LC50 values for fish range from 327 mg NO3/ L to greater than 9,300 mg NO3/ L. In addition, acute fish toxicity studies were conducted on nitrogen solutions ( UAN) and potassium sodium nitrate under Good Laboratory Practice ( GLP) conditions. The resultant LC50 values were greater than approximately 100 mg/ L, the highest concentrations tested. Acute studies with Daphnia magna resulted in EC50 values ranging from 300 to 2,614 mg NO3/ L. Chronic toxicity studies on aquatic invertebrates resulted in NOEC values of 300 mg/ L and TLm values of 327 880 mg NO3/ L. Algal toxicity studies resulted in EC50 values from 83 to 1,233 mg NO3/ L. The available ecotoxicity data indicate nitrate compounds have relatively low toxicity to terrestrial plants. Based on the standard Federal Insecticide Fungicide and Rodenticide Act ( FIFRA) acute toxicity ratings for fish and Daphnia ( below), the compounds in this category are considered practically non toxic.

EC/ LC50 ( mg/ L) Toxicity Description < 0.1 Very Highly Toxic 0.1 1 Highly Toxic 1 10 Moderately Toxic 10 100 Slightly Toxic > 100 Practically Non Toxic Mammalian Toxicity Acute toxicity The acute oral LD50 values for mammals were reported as 1,166 mg NO3/ kg bw ( potassium nitrate) and up to 5,200 mg/ kg bw for most of the remaining nitrate compounds. In addition, acute oral toxicity studies were conducted under GLP conditions for UAN and potassium sodium nitrate. Results of the acute oral toxicity studies for both materials confirmed that they were of 4 Potassium Nitrate CAS # 7757 79 1 low toxicity concern ( LD50 values > 2000 mg/ kg). An acute inhalation study using ammonium nitrate reported an LC50 of > 88.8 mg/ L, while a similar study with dogs reported an NOEC of 5 mg NO3/ m3 ( the only dose tested). Acute dermal studies were also conducted under GLP conditions. The resultant LD50s were > 5000 mg/ kg bw for both ammonium nitrate and potassium nitrate. Based on the standard FIFRA acute toxicity ratings for mammals ( below), the compounds in this category are considered to be of low to very low toxicity ( 40 CFR 156.62).

Toxicity Category I II III IV Toxicity Rating High Moderate Low Very Low Oral LD50   50 mg/ kg > 50 500 mg/ kg > 500 5000 mg/ kg > 5000 mg/ kg Dermal LC50   200 mg/ kg > 200 2000 mg/ kg > 2000 20,000 mg/ kg > 20,000 mg/ kg Inhalation LC50   0.2 mg/ L > 0.2 2 mg/ L > 2 20 mg/ L > 20 mg/ L Genotoxicity All nitrate compounds tested negative for mutagenicity using in vitro bacterial tests. Positive responses were observed at high doses ( 7.2 mg/ mL) in in vitro chromosome aberration studies with sodium nitrate only. In vivo assays were generally negative except for sodium nitrate at very high doses ( 706 mg NO3/ kg)..

Repeated dose and developmental toxicity Repeat dose studies on ammonium nitrate, potassium nitrate, and sodium nitrate indicate that materials in the nitrate category are of low acute toxicity. Developmental or teratogenic toxicity was not observed for any of the three nitrate materials for which data were available. A new repeat dose study on potassium nitrate has been conducted using the OECD Guideline 422 protocol under GLP conditions. This study provides data for three different endpoints: repeat dose toxicity, reproductive toxicity, and developmental toxicity. Results demonstrate no adverse effects on general toxicity, reproductive or developmental endpoints. The resultant NOAEL was 1,500 mg/ kg/ day.

IV. Conclusion for the Nitrate Compounds Category Substantial literature data were available for the fertilizer materials comprising the nitrate compounds category. The exceptions were nitrogen solutions ( UAN) and potassium sodium nitrate for which no specific data were available. However, UAN is an aqueous solution of ammonium nitrate and urea while potassium sodium nitrate is a simple blend of potassium nitrate and sodium nitrate. Extensive data are available for those base materials and are therefore applicable for characterization of the mixtures. In addition, aquatic and mammalian acute studies were conducted under GLP conditions to provide specific information on UAN and potassium sodium nitrate. Additional studies were also conducted under GLP conditions on 5 Potassium Nitrate CAS # 7757 79 1 ammonium nitrate and potassium nitrate to further characterize these key materials in the category. The existing data, and the results from the additional studies, adequately characterize the nitrate compounds category. Potassium Nitrate CAS # 7757 79 1 5 TABLE 1: CATEGORIES FOR PRODUCT TESTING PROJECT CATEGORY COMPOUND CAS NUMBER Ammonia Compounds Anhydrous ammonia Aqua ammonia Ammonium nitrate Ammonium sulfate Ammonium thiosulfate Nitrogen solutions ( UAN) Ammonium phosphate sulfate Diammonium phosphate ( DAP) Monoammonium phosphate ( MAP) Urea 7664 41 7 1336 21 6 6484 52 2 7783 20 2 7783 18 8 15978 77 5 12593 60 1 7783 28 0 7722 76 1 57 13 6 Nitrate Compounds Sodium nitrate Ammonium nitrate Potassium nitrate Potassium sodium nitrate Nitrogen solutions ( UAN) 7631 99 4 6484 52 2 7757 79 1 7757 79 1/ 7631 99 4 15978 77 5 Phosphate Compounds Diammonium phosphate ( DAP) Monoammonium phosphate ( MAP) Liquid polyphosphate Single superphosphate** Granular triple superphosphate** 7783 28 0 7722 76 1  8011 76 5 65996 95 4 Salts Potassium chloride Potassium magnesium sulfate Potassium nitrate Potassium sodium nitrate Potassium sulfate Calcium sulfate 7447 40 7 14168 73 1 7757 79 1 7757 79 1/ 7631 99 4 7778 80 5 7778 18 9 Acids Phosphoric acid Nitric acid Sulfuric acid 7664 38 2 7697 37 2 7664 93 9 * = Nitrogen solutions are primarily Urea Ammonia Nitrogen ( UAN; 15978 77 5) ** = Single superphosphate and granular triple superphosphate are combined into a single health and environmental safety data summary document.  = No CAS number readily available Potassium Nitrate CAS # 7757 79 1 6 V. REFERENCES CITED 40 CFR 156.62. Toxicity Category.

Al Dabbagh, S., Forman, D., Bryson, D., Stratton, I. and Doll, R. 1986. Mortality of nitrate fertilizer workers. British Journal of Industrial Medicine. 43: 507 515.

Burden, E. H. W. J. 1961. The toxicology of nitrates and nitrites with particular reference to the potability of water supplies. The Analyst. 86( 1024): 429 433.

Chow, C. K., Chen, C. J. and Gairola, C. 1980. Effect of nitrate and nitrite in drinking water in rats. Toxicology Letters. 6: 199 206.

Forman, D., Al Dabbagh, S. and Doll, R. 1985. Nitrates, nitrites and gastric cancer in Great Britain. Nature. 313( 6004): 620 625.

Leclerc, H., Vincent, P. and Vandevenne, P. 1991. Nitrates in drinking water and cancer. Bull. Acad. Natl. Med. 175( 4): 651 666.

L'hirondel, J., L'hirondel, J. L. 1998. Nitrates and Man: The Myth of Their Toxicity.

Lijinsky, W. and Epstein, S. S. 1970. Nitrosamines as environmental carcinogens. Nature 225( 227): 21 23.

Lijinsky, W. 1989. Environmental cancer risks   real and unreal. Environmental Research 50: 207 209.

Magee, P. N. and Barnes, J. M. 1967. Carcinogenic nitroso compounds. Adv. Cancer Res. 10: 163 264.

OECD. 1997. SIDS Manual. OECD Secretariat, 3rd Revision, July 1997.

Owens, F. N. and Dubeski, P. 1989. Nitrate toxicity in ruminants. ASAS Production & Management Symposium.

Rubin, A. J. and Elmaraghy, G. A. 1977. Studies on the toxicity of ammonia, nitrate and their mixtures to guppy fry. Water Research 11: 927 935.

USEPA. 1999. Development of Chemical Categories in the HPV Challenge Program. www. epa. gove/ chemrtk/ catdoc29. pdf. Potassium Nitrate CAS # 7757 79 1 7 SIDS DATA PROFILE Date: January 27, 2003 1.01 A. CAS No. 7757 79 1 1.01 C. CHEMICAL NAME ( OECD NAME) Potassium Nitrate 1.01 D CAS DESCRIPTOR Potassium Nitrate 1.01 G STRUCTURAL FORMULA KNO3 OTHER CHEMICAL IDENTITY INFORMATION Not applicable 1.5 QUANTITY 100,000  500,000 tonnes per annum 1.7 USE PATTERN Primarily used as a fertilizer. Also used in fireworks, fluxes, pickling of meats, manufacture of glass, matches and gunpowder, treating tobacco and tempering steel. 1.9 SOURCES AND LEVELS OF EXPOSURE Low human exposure is expected because potassium nitrate is manufactured in closed systems. Exposure to dusts is possible during fertilizer application. ISSUES FOR DISCUSSION The data for potassium nitrate should be evaluated in combination with the other materials in the nitrate category. Potassium Nitrate CAS # 7757 79 1 8 SIDS DATA SUMMARY Date: January 27, 2003 POTASSIUM NITRATE ( CAS NO. 7757 79 1) SPECIES PROTOCOL RESULTS PHYSICAL CHEMICAL DATA 2.1 Melting Point 344 ° C 2.2 Boiling Point 400 ° C at 760 mm Hg 2.3 Density 2.109 g/ mL at 16oC 2.4 Vapor Pressure EPISUITE V. 3.10 1.39x10 15 hPa at 25 ° C 2.5 Octanol/ Water Partition Coefficient EPISUITE V. 3.10  0.79 at 25 ° C 2.6A Water Solubility 357 g/ L at 25 ° C 2.6B pH value ~ 7 at 25oC 2.7 Flash Point Not applicable 2.8 Auto Flammability Not flammable 2.9 Flammability Not flammable 2.10 Explosive Properties May explode on contact with reducing agents and/ or impact. 2.11 Oxidizing Properties Strong oxidizer 2.12 Oxidation: Reduction Potential See Appendix B results* ENVIRONMENTAL FATE and PATHWAY 3.1.1 Photodegradation Does not photodegrade 3.1.2 Stability in Water Stable 3.1.3 Stability in Soil Stable 3.3.2 Distribution Fugacity Level III ( Mackay type) 8.34 x10 9% to air 45.3% to water 54.7% to soil 0.0755% to sediment 3.5 Biodegradation Biodegradable 3.7 Bioaccumulation Does not bioaccumulate ECOTOXICITY 4.1 Acute Toxicity to Fish Lepomis macrochirus 96 hrs LC50 = 1,839 mg NO3/ L 4.2 Acute Toxicity to Aquatic Invertebrates Daphnia magna 48 hrs TLm = 300 mg NO3/ L 4.3 Toxicity to Aquatic Plants ( Algae) See text 4.4 Toxicity to Bacteria See Appendix B results* 4.5.1 Chronic Toxicity to Fish See Appendix B results* 4.5.2 Chronic Toxicity to Aquatic Invertebrates Nereis grubei Neanthes arenaceodentata Dorvilliea articulata Capitella capita TLm = 327 mg NO3/ L TLm = 496 mg NO3/ L TLm = 880 mg NO3/ L TLm = 713 mg NO3/ L 4.6.2 Toxicity to Terrestrial Plants See text 4.6.3 Toxicity to Other Non Mammalian Terrestrial Species See Appendix B results*

* See Appendix B results for data on other chemicals in the nitrate category. Potassium Nitrate CAS # 7757 79 1 9 POTASSIUM NITRATE ( CAS NO. 7757 79 1) SPECIES PROTOCOL RESULTS TOXICITY 5.1.1 Acute Oral Toxicity Rat Rabbit Cow, sheep Goat LD50 = 3,750 mg/ kg/ bw LD50 = 1,166 mg NO3/ kg Lethal dose ( cow) = 75 140 mg NO3 N/ kg Lethal dose ( sheep) = 70 mg NO3 N/ kg LD100 = 1,000 1,500 mg/ kg 5.1.2 Acute Inhalation Toxicity See Appendix B results* 5.1.3 Acute Dermal Toxicity Rat LD50 > 5000 mg/ kg 5.1.4 Acute Toxicity, Other Routes See Appendix B results* 5.2.1 Skin Irritation/ Corrosion See Appendix B results* 5.2.2 Eye Irritation Corrosion See Appendix B results* 5.3 Skin Sensitization See Appendix B results* 5.4 Repeated Dose Toxicity Rat OECD 422 NOAEL = 1,500 mg/ kg/ day 5.5 Genetic Toxicity in vitro Bacterial reverse mutation assay Bacillus subtilis recombination assay Negative Negative 5.6 Genetic Toxicity in vivo Rat 10 weeks Negative 5.7 Carcinogenicity See Appendix B results* 5.8 Toxicity to Reproduction Rat OECD 422 NOAEL = 1,500 mg/ kg/ day Guinea pig One generation study NOAEL Parental = 10,000 ppm NOAEL F1 Offspring = 10,000 ppm Rat Two generation study NOAEL Parental = 2.5%

5.9 Developmental Toxicity/ Teratogenicity Rat OECD 422 NOAEL = 1,500 mg/ kg/ day Mouse oral; 10 day exposure NOAEL > 400 mg/ kg bw 5.11 Human Experience See text 1.8 Occupational Exposure Limits TLV as inert dust 15 mg/ m3 * See Appendix B results for data on other chemicals in the nitrate category. Potassium Nitrate CAS # 7757 79 1 10 1. GENERAL INFORMATION 1.01 SUBSTANCE INFORMATION A. CAS number 7757 79 1 B. Name ( IUPAC name) Potassium nitrate C. Name ( OECD name) Potassium nitrate D. CAS Descriptor Not applicable E. EINECS Number 231 818 8 F. Molecular Formula KNO3 G. Structural Formula KNO3 SMILES: O( N(= O)= O) K H. Substance Group Not applicable I. Substance Remark None J. Molecular Weight 101.1 1.02 OECD INFORMATION A. Sponsor Country Not applicable B. Lead Organization Not applicable C. Name of Responder Name: Mr. William C. Herz, Director of Scientific Programs Address/ Phones: The Fertilizer Institute Union Center Plaza 820 First Street, NE, Suite 430 Washington, DC 20002 USA Tel: ( 202) 962 0490 Fax: ( 202) 962 0577 Potassium Nitrate CAS # 7757 79 1 11 1.1 GENERAL SUBSTANCE INFORMATION A. Type of Substance element [ ]; inorganic [ X]; natural substance [ ]; organic [ ]; organometallic [ ]; petroleum product [ ]

B. Physical State ( at 20 ° C and 1.013 hPa)

gaseous [ ]; liquid [ ]; solid [ X]

1.2 SYNONYMS Nitrate of potash Potassium salt nitric acid Saltpeter Nitric acid, potassium salt 1.3 IMPURITIES None identified 1.4 ADDITIVES None identified 1.5 QUANTITY Remarks: 500,000 to 1,000,000 tonnes per annum. References: European Commission. 2000. International Uniform Chemical Information Database. Year 2000 CD ROM Edition.

1.6 LABELING AND CLASSIFICATION DOT Labeling Hazard Class: 5.1 NFPA Rating Health: 1 ( minimal hazard) Fire: 0 ( no hazard) Reactivity: 3 ( severe hazard) Specific: oxidizer References: 1) Mallinckrodt Baker, Inc. 1999. Material Safety Data Sheet No. P5950: Potassium Nitrate. Last revision November 17, 1999. 2) NIOSH, IPCS, International Chemical Safety Cards (# 0184). Potassium Nitrate. Potassium Nitrate CAS # 7757 79 1 12 1.7 USE PATTERN A. General Type of Use: Category:

( a) main Wide dispersive use industrial Agriculture use Fertilizer ( b) main Non dispersive use industrial Personal and domestic use use Fireworks, fluxes, pickling of meats, manufacture of glass, matches, gunpowder, and blasting powders, treating tobacco, tempering steel Remarks: About 86% for fertilizer, 6% in heat transfer salts, 4% in glass and ceramics, 2% in matches and pyrotechnics (= 1975). Reference: Hazardous Substances Data Bank ( HSDB). 1999. Potassium Nitrate. National Library of Medicine, Bethesda, MD.

B. Uses in Consumer Products No consumer product uses.

1.8 OCCUPATIONAL EXPOSURE LIMIT VALUE Exposure limit value Type: OSHA PEL Value: 15 mg/ m3 total dust; 5 mg/ m3 respirable fraction. Remark: No specific limit has been set, however, the federal OSHA PEL for particulates not otherwise regulated applies to all fertilizer dusts. Regulated limits may vary in local jurisdictions.

1.9 SOURCES OF EXPOSURE Remarks: Potassium nitrate can be absorbed into the body by inhalation of its aerosol and by ingestion, although significant human and environmental exposures during manufacture are unlikely if the process is well managed. Engineering controls such as mechanical ventilation, process or personnel enclosure, control of process conditions, and process modifications significantly reduce exposure. Local exhaust ( ventilation) control as close to the point of generation is both the most economical and safest method to minimize personnel exposure to airborne concentrations. Personal protective Potassium Nitrate CAS # 7757 79 1 13 equipment includes neoprene or nitrile gloves, dusk masks or fume hoods as appropriate, chemical safety goggles, and impervious apron, sleeves and boots. Field exposure to workers is possible when handling and using on farms as a fertilizer. However, fertilizers are applied by mechanical spreaders, which reduces contact exposure. Environmental releases are controlled at the manufacturing plant. Gaseous emissions are low due to use of scrubbers and liquid effluent is recovered as much as possible. Exposure to environmental receptors is dependent on the amount used as fertilizer on fields, the climatic conditions, and the hydrological conditions of the area of application. Nitrate materials are common in the environment and are essential nutrients for both plants and animals.

1.10 ADDITIONAL REMARKS Options for disposal Remarks: Potassium nitrate must be disposed of in accordance with federal, state and local environmental control regulations. Generally it is sufficient to mix the material with wet sand, transfer to a container and arrange removal by a disposal company. References: BDH, INC. 2000. Material safety Data Sheet: Potassium Nitrate. Last revision September 28, 2000.

2. PHYSICAL CHEMICAL DATA 2.1 MELTING POINT Value: 334 ° C Decomposition: Yes [ ] No [ ] Ambiguous [ X] Sublimation: Yes [ ] No [ ] Ambiguous [ X] Method: Not specified GLP: Yes [ ] No [ ] ? [ X] References: Lide, D. R. CRC Handbook of Chemistry and Physics. 78th Ed. 1998. New York, Lewis Publishers 2.2 BOILING POINT Value: 400 ° C Pressure: at 760 mm Hg Decomposition: Yes [ X] No [ ] Ambiguous [ ] Potassium Nitrate CAS # 7757 79 1 14 Method: Not specified GLP: Yes [ ] No [ ] ? [ X] References: 1) International Chemical Safety Cards: 0184, Third Series, Commission of the European Communities, 1991. 2) Lide, D. R. CRC Handbook of Chemistry and Physics. 78th ed. 1998. New York, Lewis Publishers.

2.3 DENSITY ( Relative Density)

Type: Bulk density [ ]; Density [ X]; Relative Density [ ] Value: 2.109 g/ mL Temperature: 16 ° C Method: Not specified GLP: Yes [ ] No [ ] ? [ X] References: Lide, D. R. CRC Handbook of Chemistry and Physics. 78th ed. 1998. New York, Lewis Publishers.

2.4 VAPOR PRESSURE Value: 1.39x10 15 hPa Temperature: 25 ° C Method: Calculated [ X]; measured [ ] GLP: Yes [ ] No [ X] ? [ ] Remarks: Estimated using EPISUITE V. 3.10. References: USEPA. 2000. EPISUITE Estimation Software. V. 3.10. US Environmental Protection Agency.

2.5 PARTITION COEFFICIENT logPow Log Pow:  0.79 Temperature: 25 ° C Method: Calculated [ X]; measured [ ] GLP: Yes [ ] No [ X] ? [ ] Remarks: Estimated using EPISUITE V. 3.10. References: USEPA. 2000. EPISUITE Estimation Software. V. 3.10. US Environmental Protection Agency.

2.6 WATER SOLUBILITY A. Solubility ( a) Value: 357 g/ L ( water) Temperature: 25 ° C Potassium Nitrate CAS # 7757 79 1 15 Description: Miscible [ ]; Of very high solubility [ ]; Of high solubility [ X]; Soluble [ ]; Slightly soluble [ ] Of low solubility [ ]; Of very low solubility [ ]; Not soluble [ ] Method: Not specified GLP: Yes [ ] No [ ] ? [ X] Remarks: Soluble in glycerol; insoluble in alcohol. References: Budavari, S. 1996. Merck Index. Whitehouse Station: Merck Research Laboratories.

( b) Value: 133 g/ L at 0oC 2470 g/ L at 100oC Description: Miscible [ ]; Of very high solubility [ X]; Of high solubility [ ]; Soluble [ ]; Slightly soluble [ ] Of low solubility [ ]; Of very low solubility [ ]; Not soluble [ ] Method: Not specified GLP: Yes [ ] No [ ] ? [ X] References: Lide, D. R. 1998. CRC Handbook of Chemistry and Physics. 178th Ed. New York, Lewis Publishers.

B. pH Value pH Value: ~ 7 Concentration: Not specified Temperature: 25 ° C Method: Not specified GLP: Yes [ ] No [ ] ? [ X] References: Budavari, S. 1996. Merck Index. Whitehouse Station: Merck Research Laboratories.

2.7 FLASH POINT ( liquids)

Remarks: Not applicable.

2.8 AUTO FLAMMABILITY ( solid/ gases)

Remarks: Not flammable. Potassium Nitrate CAS # 7757 79 1 16 2.9 FLAMMABILITY Results: Extremely flammable [ ]; Extremely flammable   liquified gas [ ]; Highly flammable [ ]; Flammable [ ]; Non flammable [ X]; Spontaneously flammable in air [ ]; Contact with water liberates highly flammable gases [ ] Method: Not specified GLP: Yes [ ] No [ ] ? [ X] Remarks: According to the National Fire Protection Agency ( NFPA), potassium nitrate has a flammability of 0, which includes any material that will not burn. However, potassium nitrate can yield gaseous oxides of nitrogen when involved in fire. References: NFPA. 1986. Protection Guide for Hazardous Materials. 9th Ed.

2.10 EXPLOSIVE PROPERTIES Results: Explosive under influence of a flame [ ]; More sensitive to friction than m dinitrobenzene [ ]; More sensitive to shock than m dinitrobenzene [ ]; Not explosive [ ]; Other [ X] Method: Not specified GLP: Yes [ ] No [ ] ? [ X] Remarks: There is a risk of fire or explosion on contact with reducing agents and/ or impact. References: NIOSH, IPCS, International Chemical Safety Cards. Potassium Nitrate: No. 0184.

2.11 OXIDIZING PROPERTIES Remarks: On contact with hot surfaces this substance decomposes forming nitrogen oxides, which increases fire hazard. The substance is a strong oxidant and reacts at high temperatures with combustible and reducing materials. It is incompatible with heavy metals, phosphites, strong acids, aluminum, aluminum oxide and acetic anhydride, causing fire and explosion hazard. References: 1) BDH, INC. 2000. Material safety Data Sheet: Potassium Nitrate. Last revision September 28, 2000. 2) Mallinckrodt Baker, Inc. 1999. Material Safety Data Sheet No. P5950: Potassium Nitrate. Last revision November 17, 1999. 3) NIOSH, IPCS, International Chemical Safety Cards: No. 0184. Potassium Nitrate CAS # 7757 79 1 17 2.12 OXIDATION: REDUCTION POTENTIAL Remarks: No data available.

3. ENVIRONMENTAL FATE AND PATHWAYS 3.1 STABILITY 3.1.1 PHOTODEGRADATION Test substance: Potassium nitrate ( KNO3) Remarks: Does not photodegrade. References: European Commission. 2000. Potassium Nitrate. International Uniform Chemical Information Database. Year 2000 CD ROM Edition.

3.1.2 STABILITY IN WATER Type: Abiotic ( hydrolysis) [ X]; biotic ( sediment) [ ] Method: Not specified GLP: Yes [ ] No [ ] ? [ X] Test substance: Potassium nitrate ( KNO3) Remarks: Potassium nitrate solubilized in water is completely dissociated into potassium and nitrate ions. In pure water both ions are stable at normal temperatures. In natural waters the ions can participate in absorption and ion exchange processes and the nitrate ion is under anaerobic conditions both chemical degradable and biodegradable. References: European Commission. 2000. Potassium Nitrate. International Uniform Chemical Information Database. Year 2000 CD ROM Edition.

3.1.3 STABILITY IN SOIL Type: Field trial [ ]; Laboratory [ ]; Other [ X] Method: Not specified GLP: Yes [ ] No [ ] ? [ X] Test substance: Potassium nitrate ( KNO3) Remarks: In completely dry soil, potassium nitrate is probably stable at all normal temperatures. As water content in the soil increases, potassium nitrate will easily solubilize in the soil solution and dissociate completely into its ions. Both ions can participate in absorption and ion Potassium Nitrate CAS # 7757 79 1 18 exchange processes. Under anaerobic conditions, the nitrate ion is chemically and biologically degradable. References: European Commission. 2000. Potassium Nitrate. International Uniform Chemical Information Database. Year 2000 CD ROM Edition.

3.2 MONITORING DATA ( ENVIRONMENTAL)

Type of measurement: Background [ X]; At contaminated site [ ]; Other [ ] Media: All Remarks: Potassium nitrate is not measured in the environment because it cannot be distinguished from other nitrates present. However, nitrate occurs in all compartments of the environment ( air, water, soil, sediments, and biota) and comes from many different sources as a result of both natural processes and man made processes. Only a very small part of nitrates occurring in the general environment will normally originate from potassium nitrate. References: European Commission. 2000. Potassium Nitrate. International Uniform Chemical Information Database. Year 2000 CD ROM Edition.

3.2 TRANSPORT AND DISTRIBUTION BETWEEN ENVIRONMENTAL COMPARTMENTS INCLUDING ESTIMATED ENVIRONMENTAL CONCENTRATIONS AND DISTRIBUTION PATHWAYS 3.3.1 TRANSPORT Remarks: No data available.

3.3.2 THEORETICAL DISTRIBUTION ( FUGACITY CALCULATION)

Method: Fugacity level I [ ]; Fugacity level II [ ]; Fugacity level III ( Mackay type) [ X]; Fugacity level IV [ ]; Other ( calculation) [ ]; Other ( measurement) [ ] Mass Distribution by Environmental Compartment: Air 8.34 x 10 9% Water 45.3% Soil 54.7% Sediment 0.0755% References: USEPA. 2000. EPISUITE Estimation Software. V. 3.10. US Environmental Protection Agency. Potassium Nitrate CAS # 7757 79 1 19 3.4 IDENTIFICATION OF MAIN MODE OF DEGRADABILITY IN ACTUAL USE Remarks: The majority of the potassium nitrate used as fertilizer is removed from the growing media by the crops. For any excess, the main mode of degradation is biodegradation or chemical degradation of the nitrate. References: European Commission. 2000. Potassium Nitrate. International Uniform Chemical Information Database. Year 2000 CD ROM Edition.

3.5 BIODEGRADATION ( a) Remarks: Biodegradation of nitrate can occur under anaerobic conditions, both under natural conditions and as a controlled process in many wastewater treatment plants, resulting in degradation products like nitrate, oxide of nitrogen, elemental nitrogen, or ammonia. References: European Commission. 2000. Potassium Nitrate. International Uniform Chemical Information Database. Year 2000 CD ROM Edition.

( b) Type: Aerobic [ ]; Anaerobic [ ]; Estimated [ X] Results: Readily biodeg. [ ]; Inherently biodeg. [ X]; Under test condition no biodegradation observed [ ]; Other [ ] Method: Estimated using EPISUITE V. 3.10 GLP: Yes [ ] No [ X] ? [ ] Test substance: Potassium nitrate ( KNO3) Remarks: The probability of rapid biodegradation according to the linear model and non linear model is 0.6994 and 0.8282, respectively. According to the primary survey model, biodegradation of the parent compound takes days to weeks. The ultimate survey model estimated complete biodegradation takes weeks. References: USEPA. 2000. EPISUITE Estimation Software. V. 3.10. US Environmental Protection Agency.

3.6 BOD5, COD OR RATIO BOD5/ COD Remarks: No data available. Potassium Nitrate CAS # 7757 79 1 20 3.7 BIOACCUMULATION Remarks: The EPISUITE V. 3.10 program estimated a log BCF of 0.5 ( BCF = 3.162) based on an estimated log Kow of 0.21. In general, the measurement of BCF is not applicable for highly water soluble compounds like potassium nitrate.

3.8 ADDITIONAL REMARKS Soil organic carbon partition coefficient: Koc = 14.3 Remarks: Estimated using EPISUITE V. 3.10. References: USEPA. 2000. EPISUITE Estimation Software. V. 3.10. US Environmental Protection Agency.

4. ECOTOXICITY 4.1 ACUTE/ PROLONGED TOXICITY TO FISH ( a) Type of test: Static [ X]; Semi static [ ]; Flow through [ ]; Other ( e. g. field test) [ ] Open system [ X]; Closed system [ ] Species: Lepomis macrochirus ( bluegill) Exposure period: 96 hours Results: LC50( 96 h) = 3,000 mg KNO3/ L ( 1,839 mg NO3/ L) Analytical monitoring: Yes [ ]; No [ X]; ? [ ] Method: Five gallon jars were placed in a constant temperature bath ( 20oC). Ten fish were placed in each container and tests were run in duplicate for every concentration. Concentration ranged from 2,100 to 4,200 mg KNO3/ L. A control group was maintained with every series of test. The pH for the various concentrations ranged from 7.47 to 8.55. GLP: Yes [ ] No [ ] ? [ X] Test substance: Analytical or reagent grade potassium nitrate ( KNO3). Remarks: No fish died at 2,100 mg KNO3/ L. At 2,400 mg KNO3/ L, the average survival rate was 80% at 96 h. At 4,200 mg KNO3/ L and 96 hours, there was 100% mortality. References: Trama, F. B., 1954. The acute toxicity of some common salts of sodium, potassium and calcium to the common bluegill. Proc. Acad. Nat. Sci. Philadelphia. 106: 185 205. Potassium Nitrate CAS # 7757 79 1 21 ( b) Type of test: Static [ X]; Semi static [ ]; Flow through [ ]; Other ( e. g. field test) [ ] Open system [ X]; Closed system [ ] Species: Gambusia affinis ( mosquito fish) Exposure period: 96 hours Results: TLm = 162 mg/ L Analytical monitoring: Yes [ ]; No [ X]; ? [ ] Method: Not specified GLP: Yes [ ] No [ ] ? [ X] Test substance: Potassium nitrate ( KNO3) Remarks: The main subject of this study was to study the toxicity of pure chemicals ( potentially occurring in refinery wastes) in turbid waters ( turbidity caused by sub soil clay). References: Wallen, I. E., Greer, W. C., and Lasater, R. 1957. Stream pollution. Toxicity to Gambusia affinis of certain pure chemicals in turbid waters. Sewage and Industrial Wastes 29( 6): 695 711.

( c) Type of test: Static [ X]; Semi static [ ]; Flow through [ ]; Other ( e. g. field test) [ ] Open system [ X]; Closed system [ ] Species: Poecilia reticulata ( guppy) Exposure period: 96 hours Results: LC50 = 191 mg N/ L ( 1378 mg KNO3/ L; 845 mg NO3/ L) Analytical monitoring: Yes [ ]; No [ X]; ? [ ] Method: Fry were exposed to a series of concentrations of potassium nitrate using aged tap water kept at 25oC. Tests were conducted in 5 gallon aquaria holding 10 or 20 fish, 6 11 mm in length. Mortality and other observations were made at 24, 48, 72 and 96 hours. GLP: Yes [ ] No [ ] ? [ X] Test substance: Potassium nitrate ( KNO3) Remarks: Additional studies with ammonia alone and mixtures of ammonia and potassium nitrate indicated that the toxicities were simply additive except at very low ammonia to nitrate ratios. References: Rubin, A. J. and Elmaraghy, G. A. 1977. Studies on toxicity of ammonia, nitrate and their mixtures to guppy fry. Water Res. 11( 10): 927 935.

4.2 ACUTE TOXICITY TO AQUATIC INVERTEBRATES A. Daphnia ( a) Type of test: Static [ X]; Semi static [ ]; flow through [ ]; Other ( e. g. field test) [ ] Open system [ X]; Closed system [ ] Species: Daphnia magna Potassium Nitrate CAS # 7757 79 1 22 Exposure period: 48 hours Results: TLm = 490 mg/ L ( 300 mg NO3/ L) Analytical monitoring: Yes [ ]; No [ X]; ? [ ] Method: As per Anderson, B. G., Andrews, T. F., Chandler, D. G., and Jahoda, W. J. 1948. The evaluation of aquatic invertebrates as assay organisms for the determination of toxicity of industrial wastes. Report from Ohio State University Research Foundation to the American Petroleum Institute, New York. GLP: Yes [ ] No [ X] ? [ ] Test substance: Potassium nitrate ( KNO3) Remarks: Dilution water was glass wool filtered University Lake water. Although 48 hour studies are standard for D. magna, 96 hour results were also reported. 96 h TLm of 39 mg/ L was found when University Lake water was used. However, a 96 h TLm of 900 mg/ L was found if the supporting media is " standard reference water". References: Dowden, B. F. and Bennett, H. J. 1965. Toxicity of selected chemicals to certain animals. Journal Water Pollution Control Federation 37( 9): 1308 1316.

4.3 TOXICITY TO AQUATIC PLANTS, e. g. algae ( a) Species: Diatoms ( 10 species) Endpoint: Biomass [ ]; Growth rate [ X]; Other [ ] Exposure period: 10 days Results: Relative rates ( as % chlorophyll a) were:

Nitrate concentration ( mmol/ L) Species 0.1 0.68 3.38 6.75 16.9 Navicula arenaria 80 95 100 107 94 Nitzschia c. f. dissipata 84 94 100 83 67 Nitzschia dubiformis 67 84 100 100 34 Nitzschia closterium 54 65 65 85 100 Amphiprora c. f. paludosa 71 89 86 100 39 Stauroneis constricta 52 92 98 102 100 Navicula cryptocephala 61 82 73 100 84 Navicula salinarum 65 73 89 100 86 Gyrosigma spencerii 76 100 100 91 70 Nitzschia sigma 92 75 100 98 58 Analytical monitoring: Yes [ ]; No [ X]; ? [ ] Method: Ten cultures of benthic diatoms were isolated from field samples from Eems Dollard Estuary ( The Netherlands). The growth rate was determined as % chlorophyll a in diatoms grown in an artificial sea water medium containing increasing amounts of potassium nitrate. GLP: Yes [ ] No [ X] ? [ ] Potassium Nitrate CAS # 7757 79 1 23 Test substance: Potassium nitrate ( KNO3) Remarks: Most of the species grew well at nitrate concentrations up to 16.9 mmol/ L. Nitrate was clearly inhibitory to Nitzschia dubiformis and Amphiprora c. f. paludosa only at the highest test concentration. References: Admiral, W. 1977. Tolerance of estuarine benthic diatoms to high concentrations of ammonia, nitrite ion, nitrate ion and orthophosphate. Marine Biology 43: 307 315.

( b) Species: Potamogeton lucens Endpoint: Biomass [ ]; Growth rate [ ]; Other [ X] ( leafy injury) Exposure period: 20 days Results: The aquatic macrophyte shows no injury to leaves of either intact plants or detached branches after 20 days in test water containing 108 ppm KNO3 ( 15 ppm N). Analytical monitoring: Yes [ ]; No [ ]; ? [ X] Method: Not specified GLP: Yes [ ] No [ ] ? [ X] Test substance: Potassium nitrate ( KNO3) References: Litau, M. and Lehrer, Y. 1978. The effect of ammonium in water on Potamogeton lucens. Aquatic Botany 5: 127 138.

4.4 TOXICITY TO BACTERIA Remarks: No data available.

4.5 CHRONIC TOXICITY TO AQUATIC ORGANISMS 4.5.1 CHRONIC TOXICITY TO FISH Remarks: No data available.

4.5.2 CHRONIC TOXICITY TO AQUATIC INVERTEBRATES ( a) Type of test: Static [ ]; Semi static [ ]; Flow through [ ]; Other ( e. g. field test) [ ] Open system [ ]; Closed system [ ] Species: Nereis grubei, Neanthes arenaceodentata, Dorvilliea articulata, Capitella capita Endpoint: Mortality [ X]; Reproduction rate [ ]; Other [ ] Exposure period: 28 days Potassium Nitrate CAS # 7757 79 1 24 Results: TLm ( N. grubei) = 534 mg KNO3/ L ( 327 mg NO3/ L) TLm ( N. arenaceodentata) = 809 mg KNO3/ L ( 496 mg NO3/ L) TLm ( D. articulata) = 1,436 mg KNO3/ L ( 880 mg NO3/ L) TLm ( C. capita) = 1,163 mg KNO3/ L ( 713 mg NO3/ L) Analytical monitoring: Yes [ ]; No [ X]; ? [ ] Method: Not specified GLP: Yes [ ] No [ X] ? [ ] Test substance: Potassium nitrate ( KNO3) References: Reisk, D. J. 1970. The effect of varying concentrations of nutrients, chlorinity and dissolved oxygen in Polychaetous annelis. Water Research 4( 11): 721 745.

( b) Type of test: Static [ ]; Semi static [ ]; Flow through [ ]; Other ( e. g. field test) [ ] Open system [ ]; Closed system [ ] Species: Hydra attenuata Endpoint: Mortality [ ]; Reproduction rate [ X]; Other [ ] Exposure period: 12 days Results: At 81.5 mg KNO3/ L ( 50 mg NO3/ L) and 245 ( 150 mg NO3/ L) mg KNO3/ L the growth rate was similar or slightly superior to that of the controls. At 408 mg KNO3/ L the rate of growth was considerably retarded, but clubbing of tentacles was not observed. Potassium nitrate was found to be the least toxic of the three nitrates ( KNO3, NaNO3, ( NH4) 2NO3) tested with a NOEL between 245 and 408 mg KNO3/ L. The cation exerted a considerable influence on the toxicity of the nitrate solutions tested. Analytical monitoring: Yes [ ]; No [ X]; ? [ ] Method: Not specified GLP: Yes [ ] No [ X] ? [ ] Test substance: Potassium nitrate ( KNO3) Remarks: Reproduction rate measured as numbers of Hydra at a given time. References: European Commission. 2000. Potassium Nitrate. International Uniform Chemical Information Database. Year 2000 CD ROM Edition.

4.6 TOXICITY TO TERRESTRIAL ORGANISMS 4.6.1 TOXICITY TO SOIL DWELLING ORGANISMS Remarks: No data available. Potassium Nitrate CAS # 7757 79 1 25 4.6.2 TOXICITY TO TERRESTRIAL PLANTS Remarks: Nitrate absorbed by plants is reduced to nitrite by the enzyme nitrate reductase. This enzyme is found in plants, certain bacterial species, and mammalian gastric tissue. The nitrite will be further reduced only when photosynthesis and carbohydrate synthesis are active. Under drought conditions, frost and shading, or deficiencies of other nutrients, each of which reduce photosynthesis and biosynthesis of protein, nitrate continues to be absorbed and may accumulate in plant tissue. References: Owens, F. N. and Dubeski, P. 1989. Nitrate toxicity in ruminants. ASAS Production and Management Symposium.

4.6.3 TOXICITY TO OTHER NON MAMMALIAN TERRESTRIAL SPECIES ( INCLUDING AVIAN)

Remarks: No data available.

4.7 BIOLOGICAL EFFECTS MONITORING ( INCLUDING BIOMAGNIFICATION)

Remarks: Potassium nitrate provides nutrients to animals and plants and does not biomagnify.

4.8 BIOTRANSFORMATION AND KINETICS Remarks: The transformation of nitrate compounds is well known.

5. TOXICITY 5.1 ACUTE TOXICITY 5.1.1 ACUTE ORAL TOXICITY ( a) Type: LD0 [ ]; LD100 [ ]; LD50 [ X]; LDL0 [ ]; Other [ ] Species/ strain: Rat Value: 3,750 mg/ kg bw. Method: Not specified GLP: Yes [ ] No [ ] ? [ X] Test substance: Potassium nitrate ( KNO3) Potassium Nitrate CAS # 7757 79 1 26 References: Nippon Yakurigaku Zasshi. 1983. 81: 469 ( cited in RTECS and European Commission 1996).

( b) Type: LD0 [ ]; LD100 [ ]; LD50 [ X]; LDL0 [ ]; Other [ ] Species/ strain: Rabbit Value: 1,166 mg NO3/ kg Method: Not specified GLP: Yes [ ] No [ ] ? [ X] Test substance: Potassium nitrate ( KNO3) References: Dollahite, R. 1974. Southwest Vet. 27: 246. ( cited in Budavari 1996 and Hazardous Substances Data Bank ( HSDB). 1999. Potassium Nitrate. National Library of Medicine, Bethesda, MD.).

( c) Type: LD0 [ ]; LD100 [ X]; LD50 [ ]; LDL0 [ ]; Other [ ] Species/ strain: Cow, sheep, pig Value: Lethal dose ( cow) = 75 140 mg NO3 N/ kg Lethal dose ( sheep) = 70 mg NO3 N/ kg Method: various GLP: Yes [ ] No [ ] ? [ ] Test substance: Potassium nitrate ( KNO3) Remarks: Heavy mortality has been recorded among pigs consuming 290 to 495 ppm NO3 N. References: Burden, E. H. W. J. 1961. The toxicology of nitrates and nitrites with particular reference to the potability of water supplies. The Analyst. 86( 1024): 429 433.

( d) Type: LD0 [ ]; LD100 [ X]; LD50 [ ]; LDL0 [ ]; Other [ ] Species/ strain: Goat Value: 1,000   1,500 mg/ kg bw. Method: Potassium nitrate was given in large quantities ( 1.0 1.2 g/ kg) to goats in order to study the in vivo mechanism of acute nitrate poisoning. GLP: Yes [ ] No [ ] ? [ X] Test substance: Potassium nitrate ( KNO3) Remarks: The fatal dose was estimated to be 1.0 1.5 g/ kg. The mean time for death to occur after the administration was 14 hours 4 minutes and was not dose related. MHb gradually increased after administration in all subjects and reached a maximum ( 62.6%) just prior to death. In the surviving goats, MHb gradually increased after administration, reached a maximum, and then gradually decreased and disappeared. Nitrate in the rumen juice showed a maximum value ( 560 3,847 ppm) after the first administration. Higher levels were detected in the groups receiving larger doses, and then part of the nitrate in the rumen juice was reduced to nitrite. It increased slightly preceding MHb. Potassium Nitrate CAS # 7757 79 1 27 In the dead animals it reached a maximum ( 190.3 ppm) just before death. It was noted that the influence of ammonia poisoning had to be considered in goats among the above described NH3 N in which more than 50 mg/ dL was detected. Nitrate and nitrite quickly absorbed into the blood and excreted into the urine. Many of the goats maintained high levels of nitrate during the experiment. The behavior of nitrite in the blood and urine varied with MHb, though the amount detected was very small ( 18.6 ppm). The blood oxygen pressure showed a very high negative correlation with MHb. In the dead goats in the PO2 declined following the increase of MHb showing minimum level ( 12.8 mm Hg) just before death. The main cause of death by acute nitrate poisoning is concluded to be oxygen shortage. References: Horio, M. 1982. Experimental clinico physiological studies on the poisoning of nitrate in ruminants. 1. Changes in methaemoglobin formation and some medicochemical properties of goats after administration of potassium nitrate. Bulletin. Nippon Veterinary Zootechnical College 0( 31): 75 87. ( cited in European Commission 1996).

5.1.2 ACUTE INHALATION TOXICITY Remarks: No data available.

5.1.3 ACUTE DERMAL TOXICITY Type: LD0 [ ]; LD100 [ ]; LD50 [ X ]; LDL0 [ ]; Other [ ] Species/ strain: Sprague Dawley rat, albino Value: > 5,000 mg/ kg Method: OECD 402, 1987. Limit test ( 5 males/ 5 females). Potassium nitrate was applied to the shaved intact skin on the backs of each rat and covered with a gauze pad. After 24 hours the pads were removed and the area gently washed with water. GLP: Yes [ X ] No [ ] ? [ ] Test substance: Potassium nitrate ( white granules) Remarks: Prior to application, the test substance was ground in a coffee mill and moistened to achieve a dry paste by preparing an 85% w/ w mixture. All animals survived, gained weight and appeared active and healthy throughout the test. No signs of toxicity were observed. References: Merkel, D. J. 2000. Acute dermal toxicity study in ratslimit test. Product Safety Labs study number 9742. Potassium Nitrate CAS # 7757 79 1 28 5.1.4 ACUTE TOXICITY BY OTHER ROUTES OF ADMINISTRATION Remarks: No data available.

5.2 CORROSIVENESS/ IRRITATION 5.2.1 SKIN IRRITATION/ CORROSION Remarks: No data available.

5.2.2 EYE IRRITATION/ CORROSION Remarks: No data available.

5.3 SKIN SENSITIZATION Remarks: No data available.

5.4 REPEATED DOSE TOXICITY Species: Rat Sex/ Strain: Male/ Female Crl: CD( SD) IGS BR Route of Administration: Gavage Exposure Period: Animals on the study were divided between two subgroups ( toxicity and reproductive subgroups). The exposure period for males and females in the toxicity subgroup was 28 days. The exposure period for reproductive subgroup males was at most 28 days. The exposure period for reproductive subgroup females was at most 53 days ( 14 days pre mating, 14 days mating, and gestational and lactational periods up to lactation day 4). Frequency of Treatment: Daily Doses: 0, 250, 750, and 1,500 mg/ kg/ day ( Doses were selected based on parameters assessed in a range finding study at concentrations up to 1,000 mg/ kg/ day) NOAEL: 1,500 mg/ kg/ day ( general toxicity) 1,500 mg/ kg/ day ( reproduction/ developmental toxicity) LOAEL: No adverse effects were seen on general toxicity endpoints. No adverse effects were seen on reproduction/ developmental toxicity endpoints GLP: Yes Method: Toxicity subgroup: Animals comprising the toxicity subgroup ( 5 males and 5 females per dose group) were administered KNO3 for 28 days ( 7 days/ week) via Potassium Nitrate CAS # 7757 79 1 29 gavage administration. Among toxicity subgroup animals, functional observations ( sensory reactivity, grip strength, motor activity) were conducted during the final days of treatment. Bleeds for hematology and blood chemistry were conducted on Day 28 of treatment. Organ weights were recorded at termination and major organs and tissues ( and any other abnormalities observed at necropsy) were processed for microscopic examination. Reproductive subgroup: Male rats ( 5 males) in the reproductive subgroup were administered KNO3 for 28 days via oral gavage. Female rats ( 10 females) in the reproductive subgroup were administered KNO3 for a period encompassing approximately 53 continuous days via oral gavage: 14 days of initial treatment, plus a maximum of 14 days of cohabitation to ensure mating, and 25 days to litter and rear their young until Day 4 of age. Histology for reproductive subgroup animals was restricted to retained reproductive organs ( and any other abnormalities observed at necropsy). Result: Toxicity subgroup: There were no treatment related deaths and no signs of overt clinical toxicity. There were no effects on body weight, food consumption, or food efficiency. Functional observational battery ( FOB) and motor activity tests identified no treatment related changes in behavior, function, or motor activity. A slight increase in blood urea nitrogen was observed in male and female rats at 1,500 mg/ kg/ day and in female rats at 750 mg/ kg/ day. Although outside the range of the historical control, the absence of other indicators of renal dysfunction ( e. g., creatinine) discounted the clinical significance of this endpoint. Minimal changes in electrolyte levels in male rats ( e. g., 10% decrease in potassium, 4% decrease in calcium, and 22% increase in phosphorus) and female rats ( 3% decrease in chloride, 4% decrease in magnesium) were observed at 1,500 mg/ kg/ day. These changes were within the range of historical control and were not considered to be of biological significance. No treatment related histopathological changes were reported. Reproductive subgroup: There were no treatmentrelated deaths and no signs of overt clinical toxicity. There were no effects on body weight, food consumption, or food efficiency. Mating performance and fertility were unaffected by treatment. All animals mated within 4 days. There were no treatment related effects on gestation length, gestation index, litter size, offspring survival indices, sex ration, offspring bodyweight, or macropathology for offspring. Test Substance: Potassium Nitrate ( KNO3) Potassium Nitrate CAS # 7757 79 1 30 Reference: Product Safety Laboratories. 2002. Potassium Nitrate: Combined Repeated Dose Toxicity Study With the Reproduction/ Developmental Toxicity Screening Test ( Oral Gavage Study in Rats). Study Number 11686.

5.5 GENETIC TOXICITY IN VITRO A. Bacterial Test ( a) Type: Bacterial reverse mutation assay ( Ames test) System of testing: S. typhimurium strains TA 98, TA 100, TA 1535, TA 1537, and TA 1538. Standard plate incorporation assay was performed. Concentration: 0.0033 to 10 mg per plate Metabolic activation: With [ ]; Without [ ]; With and Without [ X] Results: Cytotoxicity conc: With metabolic activation: not stated Without metabolic activation: not stated Precipitation conc: not stated Genotoxic effects: + ?  With metabolic activation: [ ] [ ] [ X] Without metabolic activation: [ ] [ ] [ X] Method: GLP: Yes [ ] No [ ] ? [ X] Test substance: Potassium nitrate ( KNO3) References: Prival, M. J., Simmon, V. F., and Mortelmans, K. E. 1991. Bacterial mutagenicity testing of 49 food ingredients gives very few positive results. Mutation Research 260: 321 329.

( b) Type: Bacillus subtilis recombination assay System of testing: H17 ( Rec+) and M45 ( Rec) strains Concentration: 0.005 to 0.5 M Metabolic activation: With [ ]; Without [ X]; With and Without [ ] Results: Cytotoxicity conc: Not stated Precipitation conc: Not stated Genotoxic effects: + ?  Without metabolic activation: [ ] [ ] [ X] Method: Not specified GLP: Yes [ ] No [ ] ? [ X] Test substance: Potassium nitrate ( KNO3) References: Kanematsu, N., Hara, M., and Kada, T. 1980. Rec assay and mutagenicity studies on metal compounds. Mutation Research 77: 109 116. Potassium Nitrate CAS # 7757 79 1 31 B. Non bacterial in vitro test Type: Mammalian cell gene mutation assay System of testing: Chinese hamster fibroplast Concentration: 1.0 mg/ L Metabolic activation: With [ ]; Without [ X]; With and Without [ ] Results: Cytotoxicity conc: > 1.0 mg/ L Precipitation conc: Not stated. Genotoxic effects: + ?  Without metabolic activation: [ ] [ ] [ X] Method: Not specified ( 1984) GLP: Yes [ ] No [ ] ? [ X] Test substance: Potassium nitrate ( KNO3) References: Ishidate, M., Sofuni, T., Yoshikawa, K., Nohmi, T., Savada, M., and Matsuka, A. 1984. Primary mutagenicity screening of food additives currently used in Japan. Fd. Chem. Toxic. 22( 8): 623 636.

5.6 GENETIC TOXICITY IN VIVO Type: Dominant lethal assay Species/ strain: Sprague Dawley rat Sex: Female [ ]; Male [ X]; Male/ Female [ ]; No Data [ ] Route of Administration: Oral feed Exposure period: 10 weeks Doses: not stated Results: Body weight gains did not show a clear dose response effect. The weight gains ranged from 3 to 13% above control values. The dominant lethal test produced no consistent responses to suggest that potassium nitrate is mutagenic to rats. Genotoxic effects: + ?  [ ] [ ] [ X] Method: Not specified ( 1979) GLP: Yes [ ] No [ ] ? [ X] Test substance: Potassium nitrate ( KNO3) References: Study of Mutagenic Effects of Potassium Nitrate by the Dominant Lethal Test in Rats. 1979. Government Reports Announcements and Index. Issue 26.

5.7 CARCINOGENICITY Remarks: There has been some evidence that indicates a possible formation of N nitroso compounds in foods and in tissues that contain excess nitrates/ nitrites. N nitroso compounds are known to be potent mutagens/ carcinogens. The bacteria in saliva break Potassium Nitrate CAS # 7757 79 1 32 down nitrates to harmless nitrous acid. Certain foods such as fish are rich in amine, which reacts with nitrous acid to produce nitrosamines. However, evidence suggests that the quantities of nitrosamines formed in the organism from nitrates in food are negligible; 500,000 times less than the no effect dose. All of the epidemiological studies published since 1985 concluded that there is no positive correlation between nitrate intakes and the incidence of cancer. In fact, some evidence suggests that nitrates in foods may actually play an anti carcinogenic role. References: 1) Al Dabbagh, S., Forman, D., Bryson, D., Stratton, I. and Doll, R. 1986. Mortality of nitrate fertilizer workers. British Journal of Industrial Medicine. 43: 507 515. 2) Chow, C. K., Chen, C. J. and Gairola, C. 1980. Effect of nitrate and nitrite in drinking water in rats. Toxicology Letters. 6: 199 206. 3) Forman, D., Al Dabbagh, S. and Doll, R. 1985. Nitrates, nitrites and gastric cancer in Great Britain. Nature. 313( 6004): 620 625. 4) Leclerc, H., Vincent, P. and Vandevenne, P. 1991. Nitrates in drinking water and cancer. Bull. Acad. Natl. Med. 175( 4): 651 666. 5) Lijinsky, W. 1989. Environmental cancer risks   real and unreal. Environmental Research 50: 207 209. 6) Lijinsky, W. and Epstein, S. S. 1970. Nitrosamines as environmental carcinogens. Nature 225( 227): 21 23. 7) Magee, P. N. and Barnes, J. M. 1967. Carcinogenic nitroso compounds. Adv. Cancer Res. 10: 163 264.

5.8 TOXICITY TO REPRODUCTION ( a) Remarks: See the summary in Section 5.4 for details of an OECD Guideline 422 combined repeat dose/ reproductive/ developmental toxicity study conducted in 2002.

( b) Type: Fertility [ X]; One generation study [ ]; Two generation study [ ]; Other [ ] Species/ strain: Guinea pig Sex: Female [ X]; Male [ ]; Male/ Female [ ]; No Data [ ] Route of Administration: Ingestion via drinking water Exposure period: 143   204 days Frequency of treatment: daily Post exposure observation period: none Potassium Nitrate CAS # 7757 79 1 33 Duration of the test Up to 204 days Doses: 300, 2500, 10,000 and 30,000 ppm Control group: Yes [ X]; No [ ]; No Data [ ] Concurrent no treatment [ X]; Concurrent vehicle [ ]; Historical [ ] NOAEL Parental: 10,000 ppm NOAEL F1 Offspring: 10,000 ppm Results: Reproduction was not appreciably affected by KNO3 at levels up to 10,000 ppm in drinking water. However, at 30,000 ppm reproductive performance was poor. At 30,000 ppm, one female died and had 4 mummified fetuses in utero. Method: Potassium nitrate was given in the water at concentrations of 300, 2,500, 10,000, and 30,000 ppm. Forty six female guinea pigs were used. No more than 5 guinea pigs were in any cage, and at least 1 was a male. The lowest treatment group had 6 individuals while the other treatment groups had 3 individuals. The control group had 4 individuals. GLP: Yes [ ] No [ X] ? [ ] Test substance: Potassium nitrate ( KNO3) Remarks: Concurrent studies with potassium nitrite ( KNO2) indicated more serious effects on reproduction at concentrations of 5,000 and 10,000 ppm KNO2 in drinking water. Effects included lack of live births and aborted or mummified fetuses. References: Sleight, S. D. and Atallah, O. A. 1968. Reproduction in the guinea pig as affected by chronic administration of potassium nitrate and potassium nitrite. Toxicology and Applied Pharmacology. 12: 179 185.

( c) Type: Fertility [ ]; One generation study [ ]; Two generation study [ X]; Other [ ] Species/ strain: Wistar rat Sex: Female [ X]; Male [ ]; Male/ Female [ ]; No Data [ ] Route of Administration: Oral ( diet) Exposure period: Two generations Frequency of treatment: Daily during second trimester Doses: 0.1, 0.5 and 2.5 % Control group: Yes [ X]; No [ ]; No Data [ ] Concurrent no treatment [ X]; Concurrent vehicle [ ]; Historical [ ] NOAEL Parental: 2.5% NOAEL F1 Offspring: No gross fetal malformations were observed at term except in the 2.5% group. NOAEL F2 Offspring: At term ( F2), slight fetal toxicity, including some types of anomalies, was observed in the 2.5% potassium nitrate group, but the other groups were almost normal. Results: No differences were observed between treated F1 thirteen week old neonates and controls. After normal Potassium Nitrate CAS # 7757 79 1 34 delivery of F2 offspring, growth development of the neonates was no different from controls. Method: Pregnant rats were fed a diet containing 2.5, 0.5, or 0.1% of potassium nitrate during the second trimester. After normal delivery in half of the offspring from the dams receiving potassium nitrate, the neonates were observed until the thirteenth week. The female offspring ( F1) were mated with the F1 males of the same group and fed the same diet during the second trimester. GLP: Yes [ ] No [ ] ? [ X] Test substance: Potassium nitrate ( KNO3) Remarks: The data suggest, that a dose of 2.5% potassium nitrate, which corresponds to 4 g in daily intake for humans, was slightly toxic to the F2 generation in rats. References: Kanoh, S. and Ema, M. 1978. Studies on the fetal toxicity of potassium nitrate in two generations of rats. Teratology. 18: 148.

5.9 DEVELOPMENTAL TOXICITY/ TERATOGENICITY ( a) Remarks: See the summary in Section 5.4 for details of an OECD Guideline 422 combined repeat dose/ reproductive/ developmental toxicity study conducted in 2002.

( b) Species/ strain: CD 1 mouse Sex: Female [ X]; Male [ ]; Male/ Female [ ]; No Data [ ] Route of Administration: Oral intubation Duration of the test: 17 days Exposure period: 10 days Doses: 0.4, 2.0, 100, 400 mg/ kg Control group: Yes [ X]; No [ ]; No Data [ ] Concurrent no treatment [ X]; Concurrent vehicle [ ] NOEL Maternal Toxicity: 400 mg/ kg bw. NOEL teratogenicity: 400 mg/ kg bw. Results: At the dose level of 400 mg/ kg no significant differences between test and control animals could be seen with respect to survival, number of pregnancies, number of abortions, resorptions, dead fetuses, or average fetus weight. Method: Not specified GLP: Yes [ ] No [ ] ? [ X] Test substance: Potassium nitrate ( KNO3) Remarks: Potassium nitrate is widely used as a food additive. References: Food and Drug Administration ( FDA). 1972. Teratologic Evaluation of FDA 71 81 ( Potassium Nitrate) in Mice, Rats, Hamsters and Rabbits. Final Report. FDA 71 260. Potassium Nitrate CAS # 7757 79 1 35 5.10 OTHER RELEVANT INFORMATION ( a) Type: Toxicity of intestinal cells Species/ strain: Male B6C3F1 mice ( 10 12 weeks old) Value: See remarks Method: Potassium nitrate solution was administered by oral intubation in acute doses ( 50, 100, 200, or 400 mg/ kg body weight). Groups of 4 or more animals were killed by cervical dislocation at various post dosing periods ( 1, 2, 3, 4, 5, 6, 8, 10, and 12 hours). GLP: Yes [ ] No [ ] ? [ X] Test substance: Potassium nitrate ( KNO3) Remarks: The highest incidence of apoptotic cell death occurred at the 5th 6th cell positions from the base of the crypt and at 6 hours after treatment. This study is consistent with findings that many cytotoxic agents are able to induce apoptotic cell death in murine intestinal crypts. References: Grudzinski, I. P. and Law, F. C. P. 1998. Induction of cell death in the intestinal crypt of mice following oral administration of nitrate and nitrite. Bull. Environ. Contam. Toxicol. 60: 185 193.

( b) Type: Toxicity to livestock Remarks: Several studies have evaluated the effects of nitrate on cattle and sheep. Severe nitrate poisoning ( including mortality) can occur in cattle if feed contains greater than 1.5% potassium nitrate on a dry basis. Sublethal effects ( illness, loss of milk, off feed, abortion) can occur if the ration contains 0.5   1.5% KNO3. Below 0.5% appears safe if plenty of carbohydrates are included in the ration. In sheep, 2500 mg/ kg bw. given intravenously caused dehydration, deuresir, and high KNO3 concentration in urine, but no methaemoglobinemia. " Nitrate" poisoning in livestock is actually due to the reduction of nitrate to nitrite and subsequent absorption of nitrite into the blood stream. Reference: European Commission. 2000. Potassium Nitrate. International Uniform Chemical Information Database. Year 2000 CD ROM Edition.

5.11 EXPERIENCE WITH HUMAN EXPOSURE ( a) Results: The normal fatal dose of potassium nitrate for an adult is between 15 and 35 g, although death has been reported after taking as little as 3.5 g. Potassium Nitrate CAS # 7757 79 1 36 Remarks: Symptoms of acute potassium nitrate poisoning occur in the following order: pain in the epigastrium; purging, often with blood; convulsions of the face muscles; weak irregular pulse; difficult respiration; cold extremities followed by collapse. Reference: 1) Burden, E. H. W. J. 1961. The toxicology of nitrates and nitrites with particular reference to the potability of water supplies. The Analyst. 86( 1024): 429 433. 2) Taylor's Principals and Practice of Medical Jurisprudence. 11th Ed. Vol. 2. 1957.

( b) Remarks: Several instances of adverse human effects due to excessive exposure to potassium nitrate have been recorded. Generally these effects are related to the occurrence of methaemoglobinaemia. Nitrates generally can produce methaemoglobinaemia when they are transformed into nitrites under the influence of bacterial proliferation or of a reductase held in plants. Cases of methaemoglobinaemia have been noted after an overdose of KNO3 and of bismuth subnitrate. References: European Commission. 2000. Potassium Nitrate. International Uniform Chemical Information Database. Year 2000 CD ROM Edition.

6. REFERENCES Admiral, W. 1977. Tolerance of estuarine benthic diatoms to high concentrations of ammonia, nitrite ion, nitrate ion and orthophosphate. Marine Biology 43: 307 315.

Al Dabbagh, S., Forman, D., Bryson, D., Stratton, I. and Doll, R. 1986. Mortality of nitrate fertilizer workers. British Journal of Industrial Medicine. 43: 507 515.

BDH, Inc. 2000. Material Safety Data Sheet: Potassium Nitrate. Last revision September 28, 2000.

Budavari, S. 1996. Merck Index. Whitehouse Station: Merck Research Laboratories.

Burden, E. H. W. J. 1961. The toxicology of nitrates and nitrites with particular reference to the potability of water supplies. The Analyst. 86( 1024): 429 433.

Chow, C. K., Chen, C. J. and Gairola, C. 1980. Effect of nitrate and nitrite in drinking water in rats. Toxicology Letters. 6: 199 206.

Dollahite, R. 1974. Southwest Vet. 27: 246. ( cited in Budavari 1996).

Dowden, B. F. and Bennett, H. J. 1965. Toxicity of selected chemicals to certain animals. Journal Water Pollution Control Federation 37( 9): 1308 1316. Potassium Nitrate CAS # 7757 79 1 37 European Commission. 2000. Potassium Nitrate. International Uniform Chemical Information Database. Year 2000 CD ROM Edition.

Food and Drug Administration ( FDA). 1972. Teratologic Evaluation of FDA 71 81 ( Potassium Nitrate) in Mice, Rats, Hamsters and Rabbits. Final Report. FDA 71 260. ( cited in European Commission 1996).

Forman, D., Al Dabbagh, S. and Doll, R. 1985. Nitrates, nitrites and gastric cancer in Great Britain. Nature. 313( 6004): 620 625.

Grudzinski, I. P. and Law, F. C. P. 1998. Induction of cell death in the intestinal crypt of mice following oral administration of nitrate and nitrite. Bull. Environ. Contam. Toxicol. 60: 185 193.

Hazardous Substances Data Bank ( HSDB). 1999. Potassium Nitrate. National Library of Medicine, Bethesda, MD.

Horio, M. 1982. Experimental clinico physiological studies on the poisoning of nitrate in ruminants. 1. Changes in methaemoglobin formation and some medicochemical properties of goats after administration of potassium nitrate. Bulletin Nippon Veterinary Zootechnical College 0( 31): 75 87. ( cited in European Commission 1996).

Ishidate, M., Sofuni, T., Yoshikawa, K., Nohmi, T., Savada, M., and Matsuka, A. 1984. Primary mutagenicity screening of food additives currently used in Japan. Fd. Chem. Toxic. 22( 8): 623 636. ( cited in European Commission 1996).

International Chemical Safety Cards: 0184, Third Series, Commission of the European Communities, 1991.

Kanematsu, N., Hara, M., and Kada, T. 1980. Rec assay and mutagenicity studies on metal compounds. Mutation Research 77: 109 116. ( cited in European Commission 1996).

Kanoh, S. and Ema, M. 1978. Studies on the fetal toxicity of potassium nitrate in two generations of rats. Teratology. 18: 148.

Leclerc, H., Vincent, P. and Vandevenne, P. 1991. Nitrates in drinking water and cancer. Bull. Acad. Natl. Med. 175( 4): 651 666.

Lide, D. R. CRC Handbook of Chemistry and Physics. 78th ed. 1998. New York, Lewis Publishers.

Lijinsky, W. 1989. Environmental cancer risks   real and unreal. Environmental Research 50: 207 209.

Lijinsky, W. and Epstein, S. S. 1970. Nitrosamines as environmental carcinogens. Nature 225( 227): 21 23.

Litau, M. and Lehrer, Y. 1978. The effect of ammonium in water on Potamogeton lucens. Aquatic Botany 5: 127 138. ( cited in European Commission 1996). Potassium Nitrate CAS # 7757 79 1 38 Magee, P. N. and Barnes, J. M. 1967. Carcinogenic nitroso compounds. Adv. Cancer Res. 10: 163 264.

Mallinckrodt Baker, Inc. 1999. Material Safety Data Sheet No. P5950: Potassium Nitrate. Last revision November 17, 1999.

Merkel, D. J. 2000. Acute dermal toxicity study in rats limit test. Product Safety Labs study number 9742.

NFPA. 1986. Protection Guide for Hazardous Materials. 9th Ed. ( cited in European Commission 1996).

NIOSH, IPCS, International Chemical Safety Cards (# 0184). Potassium Nitrate.

Nippon Yakuriqaku Zasshi. 1983. 81: 469 ( cited in RTECS and European Commission 1996).

Owens, F. N. and Dubeski, P. 1989. Nitrate toxicity in ruminants. ASAS Production and Management Symposium.

Prival, M. J., Simmon, V. F., and Mortelmans, K. E. 1991. Bacterial mutagenicity testing of 49 food ingredients gives very few positive results. Mutation Research 260: 321 329. ( cited in European Commission 1996).

Product Safety Laboratories. 2002. Potassium Nitrate: Combined Repeated Dose Toxicity Study With the Reproduction/ Developmental Toxicity Screening Test ( Oral Gavage Study in Rats). Study Number 11686.

Reisk, D. J. 1970. The effect of varying concentrations of nutrients, chlorinity and dissolved oxygen in Polychaetous annelis. Water Research 4( 11): 721 745. ( cited in European Commission 1996).

Rubin, A. J. and Elmaraghy, G. A. 1977. Studies on toxicity of ammonia, nitrate and their mixtures to guppy fry. Water Res. 11( 10): 927 935.

Sleight, S. D. and Atallah, O. A. 1968. Reproduction in the guinea pig as affected by chronic administration of potassium nitrate and potassium nitrite. Toxicology and Applied Pharmacology. 12: 179 185.

Study of Mutagenic Effects of Potassium Nitrate by the Dominant Lethal Test in Rats. 1979. Government Reports Announcements and Index. Issue 26. ( cited in European Commission 1996).

Taylor's Principals and Practice of Medical Jurisprudence. 11th Ed. Vol. 2. 1957.

Trama, F. B. 1954. The acute toxicity of some common salts of sodium, potassium and calcium to the common bluegill. Proc. Acad. Nat. Sci. Philadelphia. 106: 185 205.

USEPA. 2000. EPISUITE Estimation Software. V. 3.10. US Environmental Protection Agency. Potassium Nitrate CAS # 7757 79 1 39 Wallen, I. E., Greer, W. C., and Lasater, R. 1957. Stream pollution. Toxicity to Gambusia affinis of certain pure chemicals in turbid waters. Sewage and Industrial Wastes 29( 6): 695 711. ( cited in European Commission 1996). Potassium Nitrate CAS # 7757 79 1 APPENDIX A   SIDS Data Availability Summary Potassium Nitrate CAS # 7757 79 1 Explanation of Appendix A Appendix A is a SIDS Data Summary table that provides an overview of availability and quality of the data used in this Health and Environmental Safety Data Summary for Potassium Nitrate. Y ( Yes) and N ( No) designations indicate whether data are available that meet the criteria for each column. The columns are described as:

Information: Data exist that were useful for describing the data element. These data may be from standard laboratory tests or from generally recognized published sources or professional experience.

OECD Study: The data were developed using standard OECD or essentially similar ( e. g., EPA harmonized protocols) guidelines.

GLP: The data were developed under standard Good Laboratory Practice provisions. These generally represent the highest quality data.

Other Study: Studies were conducted that could not be definitively identified as following OECD or GLP protocols. These studies were included when they were determined to be of adequate quality and provided relevant information to the characterization of the compound.

Estimation Method: In some cases, data may be estimated using established structure activity relationships. These methods are common for physical chemical parameters such as octanolwater partition coefficients and water solubility.

Acceptable: This column indicates whether the data are deemed acceptable by standard acceptability criteria and professional judgment. Only the data meeting adequacy standards are included in this summary document.

SIDS Testing Recommended: This column indicates whether additional testing is recommended based on an evaluation of the available data summarized in this document. It is generally not necessary to fill all of the apparent data gaps in order to adequately characterize the inherent hazard of chemicals. Information from other data elements and from other chemicals in the category, along with professional judgment, are useful in the final determination of the need for further testing. Potassium Nitrate CAS # 7757 79 1 SIDS DATA AVAILABILITY SUMMARY DATE: January 27, 2003 Potassium Nitrate CAS No: 7757 79 1 Information OECD Study GLP Other Study Estimated Method Acceptable SIDS Testing Recommended STUDY Y/ N Y/ N Y/ N Y/ N Y/ N Y/ N Y/ N PHYSICAL CHEMICAL DATA 2.1 Melting Point Y N N Y N Y N 2.2 Boiling Point Y N N Y N Y N 2.3 Density Y N N Y N Y N 2.4 Vapor Pressure Y N N N Y Y N 2.5 Partition Coefficient Y N N N Y Y N 2.6 Water Solubility Y N N Y N Y N pH and pKa Values Y N N Y N Y N 2.8 Auto Flammability Y N N N N Y N 2.9 Flammability Y N N N N Y N 2.10 Explosive Properties Y N N N N Y N 2.11 Oxidizing Properties Y N N N N Y N 2.12 Oxidation: Reduction Potential N N N N N  N OTHER P/ C STUDIES RECEIVED Y N N Y Y Y N ENVIRONMENTAL FATE and PATHWAY 3.1.1 Photodegradation Y N N N N Y N 3.1.2 Stability in Water Y N N Y N Y N 3.1.3 Stability in Soil N N N N N  N 3.2 Monitoring Data Y N N N N Y N 3.3.1 Transport N N N N N  N 3.3.2 Distribution Y N N N Y Y N 3.5 Biodegradation Y N N N Y Y N 3.7 Bioaccumulation Y N N N Y Y N OTHER ENV FATE STUDIES RECEIVED Y N N Y Y Y N ECOTOXICITY 4.1 Acute Toxicity to Fish Y N N Y N Y N 4.2 Acute Toxicity to Daphnia Y N N Y N Y N 4.3 Toxicity to Algae Y N N Y N Y N 4.5.1 Chronic Toxicity to Fish N N N N N  N 4.5.2 Chronic Toxicity to Aquatic Invertebrates Y N N Y N Y N 4.6.1 Toxicity to Soil Dwelling Organisms N N N N N  N 4.6.2 Toxicity to Terrestrial Plants Y N N Y N Y N 4.6.3 Toxicity to Birds N N N N N  N OTHER ECOTOXICITY STUDIES RECEIVED N N N N N  N Potassium Nitrate CAS # 7757 79 1 Potassium Nitrate CAS No: 7757 79 1 Information OECD Study GLP Other Study Estimated Method Acceptable SIDS Testing Recommended STUDY Y/ N Y/ N Y/ N Y/ N Y/ N Y/ N Y/ N TOXICITY 5.1.1 Acute Oral Y N N Y N Y N 5.1.2 Acute Inhalation N N N N N  N 5.1.3 Acute Dermal Y N N Y N Y N 5.2 Skin and Eye Irritation N N N N N  N 5.3 Skin Sensitization N N N N N  N 5.4 Repeated Dose Y Y Y N N Y N 5.5 Genetic Toxicity in vitro . Gene mutation Y N N Y N Y N . Chromosomal aberration Y N N Y N Y N 5.6 Genetic Toxicity in vivo Y N N Y N Y N 5.7 Carcinogenicity Y N N N Y Y N 5.8 Reproduction Toxicity Y Y Y Y N Y N 5.9 Development/ Teratogenicity Y Y Y Y N Y N 5.11 Human Experience Y N N Y N Y N OTHER TOXICITY STUDIES RECEIVED Y N N Y N Y N Potassium Nitrate CAS # 7757 79 1 APPENDIX B   SIDS Data Summaries for the Nitrate Compounds Category: Ammonium Nitrate, Nitrogen Solutions ( UAN), Potassium Nitrate, Potassium Sodium Nitrate, and Sodium Nitrate SIDS DATA SUMMARIES FOR NITRATES CATEGORY Date: January 27, 2003 Potassium Nitrate CAS # 7757 79 1 Ammonium Nitrate Nitrogen Solution ( UAN)

DATA ELEMENTS SPECIES PROTOCOL RESULTS SPECIES PROTOCOL RESULTS PHYSICAL CHEMICAL DATA 2.1 Melting Point 169.6oC 2.2 Boiling Point 210oC 2.3 Density 1.725 g/ mL at 25oC 2.4 Vapor Pressure 15 hPa at 20oC 2.5 Octanol/ Water Partition Coefficient OECD 107  3.1 at 25oC 2.6A Water Solubility 1,920 g/ L at 20oC 2.6B pH and pKa values pH = 5.43 in aqueous solution 2.7 Flash Point Not applicable 2.8 Auto Flammability Not flammable 2.9 Flammability Not flammable 2.10 Explosive Properties May explode under high temperature or strong shocks 2.11 Oxidizing Properties Strong oxidizer SIDS DATA SUMMARIES FOR NITRATES CATEGORY Date: January 27, 2003 Potassium Nitrate CAS # 7757 79 1 Ammonium Nitrate Nitrogen Solution ( UAN)

DATA ELEMENTS SPECIES PROTOCOL RESULTS SPECIES PROTOCOL RESULTS ENVIRONMENTAL FATE and PATHWAY 3.1.1 Photodegradation Does not photodegrade 3.12 Stability in Water Stable 3.1.3 Stability in Soil Binds to clay particles 3.3 Transport and Distribution 3.3.2 Distribution Calculated,

Fugacity Level III 0.251% to air 45.4% to water 54.2% to soil 0.0757% to sediment 3.5 Biodegradation Readily biodegraded 3.7 Bioaccumulation Does not bioaccumulate SIDS DATA SUMMARIES FOR NITRATES CATEGORY Date: January 27, 2003 Potassium Nitrate CAS # 7757 79 1 Ammonium Nitrate Nitrogen Solution ( UAN)

DATA ELEMENTS SPECIES PROTOCOL RESULTS SPECIES PROTOCOL RESULTS ECOTOXICITY 4.1 Acute toxicity to Fish Cyprinus carpio L. 48 hrs LC50 = 1.15   1.72 mg unionized NH3/ L Oncorhynchus mykiss 96 hrs LC50 > 103 mg/ L Chinook salmon, rainbow trout, bluegill 96 hrs LC50 = 420   1,360 mg NO3/ L Pimephalas promelas 96 hrs LC50 between 100 and 500 mg/ L 4.2 Acute Toxicity to Aquatic Invertebrates Daphnia magna EC50 = 555 mg/ L 4.3 Toxicity to Aquatic Plants ( Algae) Scenedesmus quadricauda EC50 = 83 mg/ L 4.5.2 Chronic Toxicity to Aquatic Invertebrates Bullia digitalis Up to 7 days NOEC = 300 mg/ L 4.6.1 Toxicity to Soil Dwelling Organisms 4.6.2 Toxicity to Terrestrial Plants 4.6.3 Toxicity to Other Non Mammalian Terrestrial Species SIDS DATA SUMMARIES FOR NITRATES CATEGORY Date: January 27, 2003 Potassium Nitrate CAS # 7757 79 1 Ammonium Nitrate Nitrogen Solution ( UAN)

DATA ELEMENTS SPECIES PROTOCOL RESULTS SPECIES PROTOCOL RESULTS TOXICITY 5.1.1 Acute Oral Toxicity Rat OECD 401 LD50 = 2,800 mg/ kg bw Rat OECD 425 LD50 > 2,000 mg/ kg bw Rat OECD 401 LD50 = 2,462 mg/ kg bw Rat OECD 401 LD50 = 2,950 mg/ kg bw Rat LD50 = 4,500 mg/ kg bw 5.1.2 Acute Inhalation Rat 4 hrs LC50 > 88.8 mg/ L 5.1.3 Acute Dermal Toxicity Rat OECD 402 LC50 > 5,000 mg/ kg 5.1.4 Acute Toxicity,

Other Routes White rat Injected; 3 hrs Minimum lethal dose = 0.065 mg NH4NO3   N 5.2.1 Skin Irritation/

Corrosion Rabbit Moderately irritating Rabbit Not irritating 5.2.2 Eye Irritation/ corrosion 5.3 Skin Sensitization 5.4 Repeated Dose Rat Inhalation; 2 weeks NOAEL = 185 mg/ m3 Rat Inhalation; 4 weeks NOAEL = 1 mg/ m3 5.5 Genetic Toxicity in vitro . Gene mutation Salmonella typhimurium Bacterial reverse mutation assay Negative . Chromosomal aberration 5.6 Genetic Toxicity in vivo 5.7 Carcinogenicity SIDS DATA SUMMARIES FOR NITRATES CATEGORY Date: January 27, 2003 Potassium Nitrate CAS # 7757 79 1 Ammonium Nitrate Nitrogen Solution ( UAN)

DATA ELEMENTS SPECIES PROTOCOL RESULTS SPECIES PROTOCOL RESULTS 5.8 Toxicity to Reproduction 5.9 Development Toxicity/ Teratogenicity Rat NOAEL > 57 mg/ kg/ day 51.0 Additional Information No sensory irritation 5.11 Human Experience See text 1.8 Occupational Exposure Limits TLV as inert dust 15 mg/ m3 SIDS DATA SUMMARIES FOR NITRATES CATEGORY Date: January 27, 2003 Potassium Nitrate CAS # 7757 79 1 Potassium Nitrate Potassium Sodium Nitrate Sodium Nitrate DATA ELEMENTS SPECIES PROTOCOL RESULTS SPECIES PROTOCOL RESULTS SPECIES PROTOCOL RESULTS PHYSICAL CHEMICAL DATA 2.1 Melting Point 344oC 308oC; 307oC 2.2 Boiling Point 400oC at 760 mm Hg 380oC at 760 mm Hg 2.3 Density 2.109 g/ mL at 16oC 2.26 g/ cm3 at 20oC 2.4 Vapor Pressure EPISUITE V. 3.10 1.39x10 15 hPa at 25oC Not expected to volatilize 2.5 Octanol/ Water Partition Coefficient EPISUITE V. 3.10  0.79 at 25oC OECD 107  3.8 at 25oC 2.6A Water Solubility 357 g/ L at 25oC 874 g/ L at 20oC 2.6B pH and pKa values pH ~ 7 at 25oC pH = 7 in aqueous solution 2.7 Flash Point Not applicable Not applicable 2.8 Auto Flammability Not flammable Does not burn 2.9 Flammability Not flammable Not flammable 2.10 Explosive Properties May explode on contact with reducing agents and/ or impact. May explode at high temperatures or contact with reducing agents 2.11 Oxidizing Properties Strong oxidizer Strong oxidizer SIDS DATA SUMMARIES FOR NITRATES CATEGORY Date: January 27, 2003 Potassium Nitrate CAS # 7757 79 1 Potassium Nitrate Potassium Sodium Nitrate Sodium Nitrate DATA ELEMENTS SPECIES PROTOCOL RESULTS SPECIES PROTOCOL RESULTS SPECIES PROTOCOL RESULTS ENVIRONMENTAL FATE and PATHWAY 3.1.1 Photodegradation Does not photodegrade Does not photodegrade Does not photodegrade 3.1.2 Stability in Water Stable Stable 3.1.3 Stability in Soil Stable Binds to clay particles 3.3.2 Distribution Fugacity Level III ( Mackay type) 8.34x10 9 % to air 45.3% to water 54.7% to soil 0.0755% to sediment Fugacity Level III ( Mackay type) 0.001% to air 45.3% to water 54.7% to soil 0.076% to sediment 3.5 Biodegradation Biodegradable Biodegradable 3.7 Bioaccumulation Does not bioaccumulate Does not bioaccumulate SIDS DATA SUMMARIES FOR NITRATES CATEGORY Date: January 27, 2003 Potassium Nitrate CAS # 7757 79 1 Potassium Nitrate Potassium Sodium Nitrate Sodium Nitrate DATA ELEMENTS SPECIES PROTOCOL RESULTS SPECIES PROTOCOL RESULTS SPECIES PROTOCOL RESULTS ECOTOXICITY 4.1 Acute toxicity to Fish Lepomis macrochirus 96 hrs LC50 = 1,839 mg NO3/ L Oncorhynchus mykiss 96 hrs LC50 > 98.9 mg/ L Lepomis macrochirus 96 hrs LC50 > 8,753 mg NO3/ L Lepomis macrochirus 24 hrs TLm = 9,331 mg NO3/ L Oncorhynchus tshawtscha 96 hrs + TLm ( freshwater,

salmon) = 5,800 mg NO3/ L TLm ( 15 ppt salinity, salmon) =

4,400 mg NO3/ L Salmo gairdneri ( rainbow trout) TLm ( freshwater,

trout) = 6,000 mg NO3/ L TLm ( 15 ppt salinity, trout) =

4,650 mg NO3/ L 4.2 Acute Toxicity to Aquatic Invertebrates Daphnia magna 48 hrs TLm = 300 mg NO3/ L Daphnia magna 48 hrs TLm = 3,581 mg NaNO3/ L Various penaeid shrimp 48 hrs LC50 = 3,400 mg NO3 N/ L NOEC = 2,000 mg NO3 N/ L Penaeus monodon larvae 40 hrs LC50 > 100 mg NO3/ L Crassostrea virginica 96 hrs LC50 = 15,810 mg NO3/ L ( adults);

23,040 mg NO3/ L ( juveniles)

Mercenaria mercenaria 96 hrs LC50 > 19,840 mg NO3/ L ( adults and juveniles)

4.3 Toxicity to Aquatic Plants ( Algae) See text Scenedesmus quadricauda Toxicity threshold = 1,233 mg NO2/ L SIDS DATA SUMMARIES FOR NITRATES CATEGORY Date: January 27, 2003 Potassium Nitrate CAS # 7757 79 1 Potassium Nitrate Potassium Sodium Nitrate Sodium Nitrate DATA ELEMENTS SPECIES PROTOCOL RESULTS SPECIES PROTOCOL RESULTS SPECIES PROTOCOL RESULTS 4.5.1 Chronic Toxicity to Fish Amphiprion oscellaris 3 months % survival in larvae ( low nitrate system) = 37%

% survival in larvae ( high nitrate system) = 34%

4.5.2 Chronic Toxicity to Aquatic Invertebrates Nereis grubei Neanthes arenaceodentata Dorvilliea articulata Capitella capita TLm = 327 mg NO3/ L TLm = 496 mg NO3/ L TLm = 880 mg NO3/ L TLm = 713 mg NO3/ L Penaeus monodon 3   5 weeks LC50 > 200 mg NO3   N/ L 4.6.3 Toxicity to Other Non Mammalian Terrestrial Species Coturnix coturnix japonica ( Japanese quail) 7 days to 15 weeks LC100 = 5,280 ppm ( by day 3 post treatment)

LC100 = 5,940 ppm ( by day 4 post treatment) SIDS DATA SUMMARIES FOR NITRATES CATEGORY Date: January 27, 2003 Potassium Nitrate CAS # 7757 79 1 Potassium Nitrate Potassium Sodium Nitrate Sodium Nitrate DATA ELEMENTS SPECIES PROTOCOL RESULTS SPECIES PROTOCOL RESULTS SPECIES PROTOCOL RESULTS TOXICITY 5.1.1 Acute Oral Toxicity Rat LD50 = 3,750 mg/ kg bw Rat OECD 425 LD50 > 2,000 mg/ kg bw Rabbit LD50 = 2,680 mg/ kg bw Rabbit LD50 = 1,166 NO3/ kg Rat LD50 = 1,267,

3,236, 3,430, and 5,200 mg/ kg bw Cow, Sheep Lethal dose ( cow)

= 75 140 mg NO3

N/ kg Lethal dose ( sheep) = 70 mg NO3  N/ kg Goat LD100 = 1,000

1,500 mg/ kg 5.1.2 Acute Inhalation Dog, sheep 7.5 minutes to 4 hrs NOEC ( dog) = 5 mg/ m3 NOEC ( sheep) = 1 mg/ m3 5.1.3 Acute Dermal Toxicity Rat OECD 402 LD50 > 5,000 mg/ kg 5.1.4 Acute Toxicity,

Other Routes Dogs i. v.; 60 minutes NOEC = 100 mg NaNO3 5.4 Repeated Dose Rat OECD 422 NOAEL = 1,500 mg/ kg/ day Rat 6 weeks MTD = 5% in the diet Rat 14 months See text 5.5 Genetic Toxicity in vitro . Gene mutation Salmonella typhimurium Bacterial reverse mutation assay Negative Salmonella typhimurium Bacterial reverse mutations assay Negative Bacillus subtilis recombination assay Negative . Chromosomal aberration Chinese hamster ovary cells Chromosome aberration test Positive SIDS DATA SUMMARIES FOR NITRATES CATEGORY Date: January 27, 2003 Potassium Nitrate CAS # 7757 79 1 Potassium Nitrate Potassium Sodium Nitrate Sodium Nitrate DATA ELEMENTS SPECIES PROTOCOL RESULTS SPECIES PROTOCOL RESULTS SPECIES PROTOCOL RESULTS 5.6 Genetic Toxicity in vivo Rat 10 weeks Negative Swiss mice and Wistar rats Micronucleus assay Positive Mice Mouse germ cells Positive 5.7 Carcinogenicity Rats 104 weeks Not significantly different from controls 5.8 Toxicity to Reproduction Rat OECD 422 NOAEL = 1,500 mg/ kg/ day Beagle dog Two generation study No significant adverse effects Guinea pig One generation study NOAEL Parental =

10,000 ppm NOAEL F1 Offspring = 10,000 ppm Rat Two generation study NOAEL Parental =

2.5%

5.9 Development Toxicity/ Teratogenicity Rat OECD 422 NOAEL = 1,500 mg/ kg/ day Rat, Mouse,

Rabbit,

Syrian hamster No significant adverse effects Mouse Oral; 10 day exposure NOAEL > 400 mg/ kg bw 5.10 Metabolism and Toxicokinetics Readily absorbed and excreted 5.11 Human Experience See text See text 1.8 Occupational Exposure Limits TLV as inert dust 15 mg/ m3 TLV as inert dust 15 mg/ m3 TLV as inert dust 15 mg/ m3