NITROGUANIDINE PROFILE OF DRINKING WATER CONTAMINANTS FOR EMERGENCY RESPONSE GENERAL INFORMATION Nitroguanidine is a widely used military explo- sive because it provides thrust and stability while reducing the burning temperature and flash inten- sity of propellent formulations. Production in the United States is mainly at one Army ammunition plant. Nitroguanidine in wastewater presents the potential for aquatic pollution. The environmental fate of nitroguanidine is dominated by photolysis and biotransformation processes. The addition of organic nutrients are required for biotransformations. The end product of nitroguanidine utilization by microbes appears to be cyanamide. Adsorption of nitroguanidine to soils and sediments is not a significant fate. PHARMACOKINETICS Nitroguanidine is rapidly absorbed following ingestion and is rapidly excreted unchanged in the urine. Data indicate that it is not extensively metabolized. Limited information is available regarding its distribution following oral ingestion, but evidence suggests that it is widely distributed. HEALTH EFFECTS Humans No data are available regarding the health effects of nitroguanidine in humans. HEALTH EFFECTS Experimental Animals Exposures of rats and mice to single oral doses produced toxic effects on the respiratory, gastro- intestinal, and central nervous systems, including lack of coordination, tremors, and convulsions. Tests in rabbits indicate that nitroguanidine is not a skin irritant. When applied directly to rabbit eyes, slight conjunctival inflammation was ob- served, probably caused by undissolved nitroguanidine. In guinea pig tests, nitroguanidine did not sensitize the skin. Results of a 14-day feeding study with rats showed nitroguanidine to be an osmotic diuretic. Toxic effects of a 90-day feeding study with rats included decreased body weights and serum electrolytes, increased water consumption, and decreased heart weights (females). In a similar study of mice, males had reduced heart weights. Results of a chronic study of nitroguanidine toxicity were inconclusive. No carcinogenicity studies are available. Although no gonadotoxic or mutagenic effects were found, the reproductive study results were inconclusive. Developmental effects reported in rats and rabbits include increased fetal resorptions, decreased pup size and weight, and increased incidence of skeletal variations. In vitro and in vivo genetic nitroguanidine toxicology assays were uniformly negative. OTHER CRITERIA, ANALYSES, AND TREATMENT TECHNOLOGIES The American Conference of Governmental Industrial Hygienists (ACGIH) have not determined an 8-hour time-weighted average Threshold Limit Value for exposure to nitroguanidine. The Occu- pational Safety and Health Administration (OSHA) has not established a Permissible Exposure Limit (PEL) for nitroguanidine. The U.S. Army Environ- mental Hygiene Agency proposed an interim 8- hour workplace PEL for nitroguanidine of 4.0 mg/ m3 total dust. The preferred method for the analysis of nitroguanidine, its organic constituents, and related compounds (nitrosoguanidine, cyanoguanidine, melamine, and ammeline) in wastewater is reversed- phase, high-performance liquid chromatography. Treatment technologies available for the re- moval of nitroguanidine in wastewater include microbial degradation with lime pretreatment, strong ultraviolet light, adsorption on activated carbon, and ion exchange resins. ------- I Physical and Chemical Properties Empirical Formula Synonyms CAS Number Physical State Molecular Weight Melting Point Specific Gravity Density Solubility NH' ch4n4o2 NQ, NG, NGu, alpha-Nitroguanidine, beta-Nitroguanidine, Guanidine-1-nitro, Guanidine-nitro, Nitroguanidine, N"-nitroguanidine, N(1)-nitroguanidine, Picrite 556-88-7 Colorless, crystalline solid. Exists in two forms: alpha (needles) and beta (plates) 104.07 232-245°C (decomposes) 1.81 1.72 g/cm3 In water: 4.4 g/L at 25°C and 82.5 g/L at 100°C. In potassium hydroxide: 12 g/L at 25°C. In 40% H2S04: 80g/Lat25°C. NH2' \ C = N—N02 Health Effects Data and Advisory Values Genotoxicity No genetic effects seen in Salmonella typhimurium strains, no mitotic recombination in Saccharomyces cerevisiae, and no DNA damage/ repair in Escherichia coli strains. Possible sex-linked recessive lethal mutation in Drosophila melanogaster. Negative in several in vitro and in vivo assays. Reproductive and Developmental Effects No reproductive effects. Increased fetal resorptions, decreased pup size and weight, and increased incidence of skeletal variations in rat and rabbit developmental studies. Cancer Classification EPA Group D, not classifiable as to human carcinogenicity. Reference Dose (RfD) 0.105 mg/kg/day Drinking Water Equivalent Level (DWEL) 4 mg/L Health Advisory Values One-Day Ten-Day Longer-Term (child) Longer-Term (adult) Lifetime 11 mg/L 11 m^L 11 mg/L 37 mg/L 0.74 mg/L This summary was developed using information from the Drinking Water Health Advisory. For further information contact EPA's Office of Science and Technology at (202) 260-7571. Office of Science and Technology Office of Water U.S. Environmental Protection Agency 401 M Street, SW Washington, DC 20460 June 17,1991 ------- |