2,4Dinitrotoluene [factsheet]

2,4-DINITROTOLUENE

Please Note: The main sources of information for this fact sheet are EPA's Integrated Risk Information System (IRIS), which contains information on oral chronic toxicity and the RfD, and the Agency for Toxic Substances and Disease Registry's (ATSDR's) Toxicological Profile for 2,4-Dinitrotoluene, and EPA's Health Effects Assessment for 2,4-Dinitrotoluene. Other secondary sources include the Hazardous Substances Data Bank (HSDB), a database of summaries of peer-reviewed literature, and the Registry of Toxic Effects of Chemical Substances (RTECS), a database of toxic effects that are not peer reviewed.

Environmental/Occupational Exposure

* Human exposure to 2,4-dinitrotoluene appears to be primarily occupational, via inhalation or dermal contact. (1)

Assessing Personal Exposure

* 2,4-Dinitrotoluene and its breakdown products can be detected in urine to determine whether or not exposure has occurred. Testing must occur within 24 hours of exposure. (1)

Health Hazard Information

Acute Effects:

* Information on the acute (short-term) effects of 2,4-dinitrotoluene on humans is not available.

* Animals acutely exposed to 2,4-dinitrotoluene by ingestion developed cyanosis and ataxia. (1)

* Acute animal tests, such as the LD₅₀ test in rats, mice, and guinea pigs, have demonstrated 2,4-dinitrotoluene to have moderate to high acute toxicity from oral exposure. (2)

Chronic Effects (Noncancer):

* Chronic (long-term) inhalation exposure to 2,4-dinitrotoluene affects the CNS, resulting in an unpleasant metallic taste in the mouth, muscular weakness, headache, appetite loss, giddiness, dizziness, nausea, insomnia, and tingling pains in the extremities in humans. (1,3)

* Effects to the blood, causing pallor, cyanosis, and anemia, have been reported among workers chronically exposed to high levels of 2,4-dinitrotoluene vapor. (1)

* Elevated mortality from heart disease has been reported among chronically exposed workers; however, this study was limited by a small cohort size. (1,3)

* Chronic oral exposure of dogs and mice has resulted in muscular incoordination, weakness, tremors, convulsions, ataxia, and paralysis. (1,4)

* Cyanosis has been observed in rats, and anemia has been observed in dogs, mice, and rats chronically exposed by ingestion. (1)

* Chronic oral exposure has been observed to cause effects on the liver and kidneys in animals. (1)

* EPA has not established an RfC for 2,4-dinitrotoluene due to inadequate data. (4)

* The RfD for 2,4-dinitrotoluene is 0.002 mg/kg/d based on neurotoxicity in dogs. (4)

* EPA has high confidence in the study on which the RfD was based because the toxic effects are based on an adequate number of animals of both sexes and a variety of histological, hematologic, and clinical endpoints were evaluated; high to medium confidence in the database because there are numerous acute, subchronic, chronic, and lifetime studies in several mammalian species. However, developmental toxicity studies are lacking; and, consequently, high to medium confidence in the RfD. (4)

Reproductive/Developmental Effects:

* A significant reduction in sperm counts and normal sperm morphology has been observed in chronically exposed workers. The fertility of occupationally exposed workers was not significantly impaired. (1)

* A small, but statistically significant, increase in spontaneous abortions was reported in one study of chronically exposed workers; several methodological problems with the study were noted. (1)

* In animals orally exposed to 2,4-dinitrotoluene, decreased fertility was reported. Decreased sperm production, testicular atrophy, and degenerated seminiferous tubules were observed in males, and ovarian atrophy and dysfunction were observed in female rats. (1,4,5)

Cancer Risk:

* No significant increase in cancer mortality was observed in workers occupationally exposed to 2,4-dinitrotoluene by inhalation. (1)

* Renal tumors were observed in male mice and liver tumors were observed in rats orally exposed to 2,4-dinitrotoluene. (1,5)

* EPA has classified 2,4-dinitrotoluene as a Group B2, probable human carcinogen. (6)

* EPA's Office of Air Quality Planning and Standards, for a hazard ranking under Section 112(g) of the Clean Air Act Amendments, has ranked 2,4-dinitrotoluene in the nonthreshold category. The 1/ED₁₀ value is 3.8 per (mg/kg)/d and this would place it in the medium category under Superfund's ranking for carcinogenic hazard. (6)

Physical Properties

* The chemical formula for 2,4-dinitrotoluene is C₇H₆N₂O₄, and its molecular weight is 182.14 g/mol. (1)

* 2,4-Dinitrotoluene occurs as a yellow solid and has a solubility in water of 270 mg/L at 22 EC. (1)

* 2,4-Dinitrotoluene has a slight odor; the odor threshold has not been established. (1)

* The vapor pressure for 2,4-dinitrotoluene is 0.0051 mm Hg at 20 EC, and the log octanol/water partition coefficient (log K_ow) is 2.0. (1)

Uses

* The predominant use of 2,4-dinitrotoluene is as an intermediate in the manufacture of polyurethanes. (1)

* 2,4-Dinitrotoluene is also used for the production of explosives, for which it is a gelatinizing and waterproofing agent. Other applications include uses as an intermediate in dye processes and in smokeless gunpowders. (1)

Health Data from Inhalation Exposure

Concentration (mg/m³)	Health numbers^a	Regulatory, advisory numbers^b	Reference
1,000,000.0
_ _ _ _ 100,000.0
_ _ _ _ 10,000.0
_ _ _ _ 1,000.0
_ _ _ _ 100.0
_ _ _ _ 10.0
_ _ _ _ 1.0		* ACGIH TLV, NIOSH REL, and OSHA PEL (1.5 mg/m³)	3

ACGIH TLVCAmerican Conference of Governmental and Industrial Hygienists' threshold limit value expressed as a time-weighted average; the concentration of a substance to which most workers can be exposed without adverse effects.

NIOSH RELCNational Institute of Occupational Safety and Health recommended exposure limit; NIOSH-recommended exposure limit for an 8- or 10-h time-weighted-average exposure and/or ceiling.

OSHA PELCOccupational Safety and Health Administration's permissible exposure limit expressed as a time-weighted average; the concentration of a substance to which most workers can be exposed without adverse effect averaged over a normal 8-h workday or a 40-h workweek.

^a Health numbers are toxicological numbers from animal testing or risk assessment values developed by EPA.

^b Regulatory numbers are values that have been incorporated in Government regulations, while advisory numbers are nonregulatory values provided by the Government or other groups as advice.

References

1. Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological Profile for 2,4-Dinitrotoluene and 2,6-Dinitrotoluene. U.S. Public Health Service, U.S. Department of Health and Human Services, Atlanta, GA. 1989.

2. U.S. Department of Health and Human Services. Registry of Toxic Effects of Chemical Substances (RTECS, online database). National Toxicology Information Program, National Library of Medicine, Bethesda, MD. 1993.

3. U.S. Department of Health and Human Services. Hazardous Substances Data Bank (HSDB, online database). National Toxicology Information Program, National Library of Medicine, Bethesda, MD. 1993.

4. U.S. Environmental Protection Agency. Integrated Risk Information System (IRIS) on 2,4-Dinitrotoluene. Environmental Criteria and Assessment Office, Office of Health and Environmental Assessment, Office of Research and Development, Cincinnati, OH. 1993.

5. U.S. Environmental Protection Agency. Health Effects Assessment for 2,4- and 2,6-Dinitrotoluene. EPA/600/8-88/032. Environmental Criteria and Assessment Office, Office of Health and Environmental Assessment, Office of Research and Development, Cincinnati, OH. 1988.

6. U.S. Environmental Protection Agency. Technical Background Document to Support Rulemaking Pursuant to the Clean Air ActCSection 112(g). Ranking of Pollutants with Respect to Hazard to Human Health. EPAB450/3-92-010. Emissions Standards Division, Office of Air Quality Planning and Standards, Research Triangle Park, NC. 1994.