National Toxicology Program

Selected toxicity information from HSDB, one of the National Library of Medicine's databases. ¹

Names (NTP)

• 2,4-Dinitrotoluene
• 1-METHYL-2,4-DINITROBENZENE (9CI)

Human Toxicity Excerpts

• ... in ... poisoning, each (and all) of the following signs has been observed: methemoglobinemia, anemia, leukopenia, and liver necrosis. Liver injury may be more common than cyanosis ... . /Dinitrotoluene/ [Gosselin, R.E., R.P. Smith, H.C. Hodge. Clinical Toxicology of Commercial Products. 5th ed. Baltimore: Williams and Wilkins, 1984., p. II-213]**PEER REVIEWED**
  
• The following symptoms have been reported as a result of varying doses of 2,4-DNT: vertigo, fatigue, dizziness, weakness, nausea, vomiting, dyspnea, arthralgia, insomnia, tremor, paralysis, unconsciousness, chest pain, shortness of breath, palpitation, anorexia, and loss of weight. [USEPA; Ambient Water Quality Criteria Doc: Dinitrotoluene p.C-16 (1980) EPA 440/5-80-045]**PEER REVIEWED**
  
• ... Workers handling compounds such as ... nitrotoluenes ... occasionally exhibit Heinz bodies (granules in red blood cells due to damage of the hemoglobin molecules). /Nitrotoluenes/ [Hugs JP, Treon JF; Arch Ind Hyg Occup Med 19: 54 (1954) as cited in USEPA; Ambient Water Quality Criteria Doc: Dinitrotoluene p.C-18 (1980) EPA 440/5-80-045]**PEER REVIEWED**
  
• Cyanosis due to the absorption of 2,4-DNT occurs when the methemoglobin of the blood is 15% or more. The symptoms observed include blueness of the lips, the nose, and the earlobes. The individual usually feels well, has no complaints, and insists that nothing is wrong until the methemoglobin concn approaches approximately 40%, when there usually is weakness and dizziness; at levels of about 70% methemoglobin, there may be ataxia, dyspnea on mild exertion, tachycardia, nausea, vomiting, and drowsiness. [USEPA; Ambient Water Quality Criteria Doc: Dinitrotoluene p.C-18-9 (1980) EPA 440/5-80-045]**PEER REVIEWED**
  
• The metabolic disturbances in workers exposed to 2,4-DNT were extensively studied. A number of signs and symptoms of chemical intoxication appear in a large group of inexperienced workmen following their introduction into military screening and coating houses which use 2,4-DNT. The chief symptoms of a group of 154 workers exposed were an unpleasent metallic taste, weakness, headache, loss of appetite, and dizziness. Two-thirds of the men in the group selected for study had these complaints at one time or another during the twelve-month exposure period. One-half of the group developed clinical signs of intoxication, chiefly pallor, cyanosis, and a low grade anemia. ... No instances of permanent physical impairment were found. [McGee LC et al; Am J Dig Dis 9: 329 (1942) as cited in USEPA; Ambient Water Quality Criteria Doc: Dinitrotoluene p.C-21 (1980) EPA 440/5-80-045]**PEER REVIEWED**
  
• Dinitrotoluene is an explosive substance which has been known to cause systemic intoxication. A workman employed for a year in nitration of mononitrotoluene to dinitrotoluene developed tingling and numbness in the toes and legs, but no pain. After two years these symptoms became worse, and vision decreased from 20/40 to 6/200 in both eyes. Cursory examination of the fields showed them to be full, but the optic nerveheads appeared atrophic and the retinal arteries were narrow. The work was discontinued, and after a year vision improved to 20/40 and 20/60, but slight paresthesia of the feet persisted. /Dinitrotoluene/ [Grant, W.M. Toxicology of the Eye. 3rd ed. Springfield, IL: Charles C. Thomas Publisher, 1986., p. 362]**PEER REVIEWED**
  
• ... The mortality experience of exposed workers at two ammunition plants /was examined/. Cohorts of 156 and 301 men who had worked a month or more during the 1940s and 1950s at jobs with opportunity for substantial dinitrotoluene exposure were followed through the end of 1980. Numbers of expected deaths and standardized mortality ratios were computed, using mortality rates of US white males as the standard. No evidence of a carcinogenic effect was found, but unsuspected excesses of mortality from ischemic heart disease were noted at both plants (standard mortality ratios) 131 and 143; 95% confidence limits 65 to 234 and 107 to 187, respectively. Deaths from ischemic heart disease remained high even when compared with expected numbers derived using mortality rates of the counties in which the plants were located. Additional analyses revealed evidence of a 15 year latent period and suggested a relationship with duration and intensity of exposure. Epidemiologic investigations of other heavily exposed populations are needed to confirm the etiologic significance of the association between dinitrotoluene and heart disease described here. /Dinitrotoluene/ [Levine RJ et al; J Occup Med 28 (9): 811-6 (1986)]**PEER REVIEWED**
  
• The urinary concentration of 2,4-dinitrobenzoic acid was tested as an index of dinitrotoluene adsorption. Spot urine samples were collected from 28 male and female workers involved in dinitrotoluene production. Twenty one workers were employed in the filling area and seven were employed in the milling operations. Tests were conducted before the start of production and daily at the end of the work shift. All urine excreted by five workers was collected on 2 work days and on 2 succeeding days off. Routine atmospheric data was collected using personal samplers. The concentration of 2,4-dinitrobenzoic acid in urine was low at the beginning of the work week but increased by the end of the week averaging 17 mg/ml. Atmospheric concentrations were below threshold limit values. No difference in urinary concentration based on tasks was observed. There was some difference in the concentration of 2,4-dinitrobenzoic acid in the urine of females and males. Intense monitoring indicated that dinitrotoluene uptake was rapid and highest in specimens taken at the end of the work shift. Detectable amounts of 2,4-dinitrobenzoic acid were noted in urine up to 2 days after the last exposure. It was concluded that biological monitoring of the urinary excretion of 2,4-dinitrobenzoic acid is a satisfactory method for assessing the degree of dinitrotoluene absorption. Atmospheric monitoring does not reflect dinitrotoluene absorption since the skin, rather than the respiratory system, is the major route of dinitrotoluene absorption. [Woollen BH et al; Int Arch Occup Environ Health 55 (4): 319-30 (1985)]**PEER REVIEWED**
  
• Cohort studies of workers suggest that exposure to 2,4 DNT leads to an increased incidence of mortality from ischemic heart disease. [Ellenhorn, M.J., S. Schonwald, G. Ordog, J. Wasserberger. Ellenhorn's Medical Toxicology: Diagnosis and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams and Wilkins, 1997., p. 1367]**PEER REVIEWED**
  
• 2,4-Dinitrotoluene is toxic by inhalation and ingestion. It is a mucous membrane irritant and may cause methemoglobinel [Sullivan, J.B. Jr., G.R. Krieger (eds.). Hazardous Materials Toxicology-Clinical Principles of Environmental Health. Baltimore, MD: Williams and Wilkins, 1992., p. 536]**PEER REVIEWED**
  

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Non-Human Toxicity Excerpts

• 2,4-DNT AT 0.5% IN DIET FED AD LIBITUM TO MALE RATS FOR 6 MO CAUSED SIGNIFICANT CHANGES IN BODY WT, ORGAN WT, BEHAVIOR, MORTALITY & BIOCHEM ANAL OF BLOOD & SERUM. DIETARY ADMINISTRATION OF 2,4-DNT /DECREASED/ BODY WEIGHT. MORTALITY WAS ABOUT 71% FOR THE SIX MONTHS. AS THE CONSPICUOUS POISONING SYMPTOMS, HUMPBACK, JERKY INCOORDINATION, PILOERECTION AND WHITENED SKIN COLOR WERE OBSERVED. ON THE MACROSCOPICAL FINDINGS, FORMATION OF PURULOID MATTER WAS SEEN IN THE LIVER. HYPERTROPHY WAS SEEN IN LIVER AND ATROPHY WAS SEEN IN TESTIS. AMOUNT OF METHEMOGLOBIN WAS INCREASED AT SEVEN-FOLD OF CONTROL LEVEL. ACTIVITIES OF SERUM ENZYMES EXCEPT GLUTAMIC PYRUVATE TRANSAMINASE WERE INCREASED SIGNIFICANTLY AND CONTENT OF ALBUMIN AND RATIO OF A/G WERE DECREASED SIGNIFICANTLY. [KOZUKA H ET AL; J TOXICOL SCI 4 (3): 221 (1979)]**PEER REVIEWED**
  
• In a screening assay based on increased multiplicity and incidence of lung tumors in a strain of mice highly susceptible to the development of this neoplasm, groups of 26 male and 26 female strain A mice, six to eight weeks old, were given 2,4-dinitrotoluene (at a purity of 92-95%, with the major impurity being 2,6-dinitrotoluene) in tricaprylin by gavage twice a week for 12 weeks (total doses, 0, 1200, 3000 and 6000 maximal) tolerated dose, MTD) mg/kg body weight). Surviving mice were killed 18 weeks after the last treatment and examined for the gross appearance of lung tumors. Survival was 45/50 in controls, 47/52 at the low dose, 48/52 at the mid dose and 44/52 at the high dose. There was no increase in lung tumor incidence or in the number of lung tumors per mouse when compared to controls. The incidence of lung tumors in survivors was 27% in controls, 28% at the low dose, 31% at the mid dose and 23% at the high dose. [IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work)., p. V65 320 (1996)]**PEER REVIEWED**
  
• IN DOGS, ORAL ADMIN OF 0.2 MG/KG/DAY BY CAPSULE HAD NO APPARENT EFFECTS, 1.5 MG/KG/DAY WAS TOXIC TO SOME, & 10 MG/KG/DAY WAS TOXIC TO ALL & LETHAL TO SOME. [ELLIS HV II ET AL; ISS ORDER NO AD-A077692, 281 PAGES (1978)]**PEER REVIEWED**
  
• IN MICE, 13.5 MG/KG/DAY IN FEED WAS TOXIC TO SOME, 95 MG/KG/DAY TOXIC TO ALL, AND 900 MG/KG/DAY HALVED LIFESPAN. TARGET ORGANS INCL BLOOD, CNS, LIVER, KIDNEY & GONADS. PIGMENT DEPOSITS WERE FOUND IN LIVERS, KIDNEYS, AND OTHER ORGANS, ESP IN MICE. [ELLIS HV II ET AL; ISS ORDER NO AD-A077692, 281 PAGES (1978)]**PEER REVIEWED**
  
• IN RATS, 0.57 OR 0.71 MG/KG/DAY 2,4-DINITROTOLUENE IN FEED HAD NO APPARENT EFFECT, 3.9 OR 5.1 MG/KG/DAY WAS TOXIC TO SOME, & 34 OR 45 MG/KG/DAY WAS TOXIC TO ALL & DECR LIFESPAN. TARGET ORGANS INCL BLOOD, CNS, LIVER, KIDNEY & GONADS. INCR INCIDENCE OF BACKGROUND SC & MAMMARY TUMORS WERE OBSERVED. [ELLIS HV II ET AL; ISS ORDER NO AD-A077692, 281 PAGES (1978)]**PEER REVIEWED**
  
• AT 50% LD50 2,4-DINITROTOLUENE INDUCED 15% METHEMOGLOBINEMIA IN RATS. [VASILENKO NM; TR KHARK MED INST 124: 34 (1976)]**PEER REVIEWED**
  
• 2,4-DINITROTOLUENE (2,4-DNT) AND ITS METABOLITES WERE TESTED FOR MUTAGENICITY IN SALMONELLA TYPHIMURIUM STRAINS TA98 AND TA100. 2,4-DNT ITSELF WAS ONLY A WEAK MUTAGEN. IN CONTRAST, 2,4-DINITROBENZALDEHYDE WAS MUTAGENIC EVEN AT MICROMOLAR CONCN IN BOTH STRAINS. THESE RESULTS SUGGEST THAT A HIGH MUTAGENICITY OF 2,4-DINITROBENZALDEHYDE MAY BE CORRELATED TO THE CARCINOGENICITY OF 2,4-DNT. [MORI MA ET AL; TOXICOL LETT 13 (1-2): 1-5 (1982)]**PEER REVIEWED**
  
• THE MUTAGENIC EFFECTS OF 2,4-DINITROTOLUENE (2,4-DNT), PURIFIED AND TECH GRADES, WERE TESTED IN MICE USING ONE OR MORE OF THE FOLLOWING: THE DOMINANT LETHAL ASSAY, THE SPERM MORPHOLOGY TEST AND/OR THE RECESSIVE SPOT TEST. CMPD WERE ADMIN BY BOTH IP INJECTION AND GAVAGE, AND COMPARISONS WERE MADE BETWEEN CONTROLS AND TREATED GROUPS AS WELL AS BETWEEN ROUTES OF ADMIN. NONE OF THE 5 CMPD TESTED PRODUCED A SIGNIFICANT RESPONSE IN ANY OF THE SYSTEMS EMPLOYED. [SOARES ER, LOCK LF; ENVIRON MUTAGEN 2 (2): 111-24 (1980)]**PEER REVIEWED**
  
• MUTAGENICITY OF 0-2.0 M TECHNICAL GRADE DINITROTOLUENE (COMPOSED PREDOMINANTLY OF 2,4- & 2,6-DNT WITH LESSER AMT OF 2,3-, 2,5-, 3,4- & 3,5-ISOMERS) AND PURIFIED ISOMERS OF DINITROTOLUENE WERE EVALUATED USING CHINESE HAMSTER OVARY/HYPOXANTHINE GUANINE PHOSPHORIBOSYLTRANSFERASE SYSTEM, A QUANTITATIVE MAMMALIAN SOMATIC CELL MUTATIONAL ASSAY. THEY WERE TESTED FOR THE ABILITY TO INDUCE MUTATION TO 6-THIOGUANINE RESISTANCE IN PRESENCE & ABSENCE OF MICROSOMAL PREPARATIONS FROM RATS PRETREATED WITH MIXED FUNCTION OXIDASE INDUCER AROCLOR 1254. NEITHER TECHNICAL GRADE DNT NOR ANY OF THE PURIFIED ISOMERS RESULTED IN SIGNIFICANT INCR IN 6-THIOGUANINE-RESISTANT FRACTION OF SURVIVING CELLS, WITH OR WITHOUT ADDED MICROSOMAL PREPARATIONS. /DINITROTOLUENE/ [ABERNETHY DJ, COUCH DB; MUTAT RES 103: 53 (1982)]**PEER REVIEWED**
  
• ... VARIOUS ISOMERS OF DINITROTOLUENE ARE CONSIDERABLY LESS TOXIC TO MOUSE, THAN TO RAT ... 2,4-, 2,6- & 3,4-ISOMERS ARE FAR MORE TOXIC TO RAT THAN ARE 2,3- & 2,5-ISOMERS ... INDICATING WIDELY DIFFERING CAPACITIES OF RAT TO METAB DNT ISOMERS DIFFERING ONLY IN POSITION ON AROMATIC RING. [American Conference of Governmental Industrial Hygienists. Documentation of the Threshold Limit Values and Biological Exposure Indices. 5th ed. Cincinnati, OH: American Conference of Governmental Industrial Hygienists, 1986., p. 216]**PEER REVIEWED**
  
• 2,4-DNT produces Heinz bodies (granules in red blood cells due to damage of the hemoglobin molecules) in the cat. [Bredow Mv, Jung F, Arch Exp Pathol Pharmakol 200: 335 (1942) as cited in USEPA; Ambient Water Quality Criteria Doc: Dinitrotoluene p.C-18 (1980) EPA 440/5-80-045]**PEER REVIEWED**
  
• Sc injection in cats with 0.05 to 0.5 g of 2,4-DNT dissolved in mineral oil resulted in death within 2 to 23 days. [Kuhls F; Inaug Dissert (1908) as cited in USEPA; Ambient Water Quality Criteria Doc: Dinitrotoluene p.C-19 (1980) EPA 440/5-80-045]**PEER REVIEWED**
  
• ... The primary subacute toxic effects of 2,4- and 2,6-DNT are seen in the red cells, nervous system, and testes. [USEPA; Ambient Water Quality Criteria Doc: Dinitrotoluene p.C-26 (1980) EPA 440/5-80-045]**PEER REVIEWED**
  
• Dinitrotoluene containing 76% of the 2,4-DNT isomer was administered in the diet to groups of male and female albino rats (10/sex/group) for four weeks at levels of 0, 27.5, 75, and 150 mg/kg body wt/day. ... No compound related effects were noted in evaluation of clinical signs or mortality of the animals in the treated groups. Mean body weights of females treated at the 75 and 150 mg/kg/day levels and of males at all levels were significantly less than the body weights of the control animals (p< 0.05). ... Methemoglobin values for females treated with 37.5 mg/kg/day and for males and females treated with 150 mg/kg/day were significantly higher than values for control animals (p< 0.05). Animals at all levels of dinitrotoluene treatment demonstrated significantly higher percentages of reticulocytes and Heinz bodies than the control animals (p< 0.05). Necropsy findings in animals receiving 150 mg/kg/day revealed apparent compound related alterations in the spleen (discoloration, enlargement, and surface irregularity) in both males and females, and discoloration of the kidney in the males. Males at all treatment levels had livers with discolorations and/or surface irregularities. [Chem Indus Inst of Tox Report: A Thirty Day Toxicology Study in Fischer-344 Rats Given Dinitrotoluene, Technical Grade Docket # 22397 p.1-2 (1978)]**PEER REVIEWED**
  
• Chronic toxicity of 2,4-dinitrotoluene was studied in beagle dogs. The major adverse effect of 2,4-DNT in dogs was a neuropathy, characterized by incoordination and paralysis, and gliosis of the cerebellum of some affected dogs. These effects were seen in dogs given 10 mg/kg/day for two years, and in all dogs given 25 mg/kg/day within two months. There was great variation between individuals in onset and severity of the adverse effects. Some dogs progressed to a complete paralysis, leading to death. Methemoglobin and its sequlae were common, but not life threatening. Heinz bodies were a useful indicator of this effect. [Ellis HV et al; J Am Coll Toxicol 4 (4): 233-42 (1985)]**PEER REVIEWED**
  
• 2,4-Dinitrotoluene (technical grade) is known to be mutagenic to bacteria in vitro. A positive response was observed for 2,4-dinitrotoluene in the liver assay for unscheduled DNA synthesis at a dose level of 200 mg/kg. [Ashby J et al; Arch Toxicol 58 (1): 14-9 (1985)]**PEER REVIEWED**
  
• Rats which over a 1 yr period ingested diets containing a technical grade mixture of dinitrotoluene, primarily composed of 2,4-DNT and 2,6-DNT, or which were fed only 2,6-DNT developed liver cancer. The liver cancers consisted of hepatocellular carcinomas and in some cases cholangiocarcinomas. Feeding or oral administration of dinitrotoluene or 2,6-DNT for less than or equal to 2 yr induced decreased spermatogenesis, aspermatogenesis, or testicular atrophy in dogs, rats, or mice. Nonfunctioning ovaries were found in mice fed dinitrotoluene for 2 yr. [NIOSH; Current Intelligence Bulletin: Dinitrotoluenes p.26 (1985) DHHS(NIOSH) Pub No. 85-109]**PEER REVIEWED**
  
• 1-Chloro-2,4-dinitrobenzene and m-dinitrobenzene were mutagenic in Salmonella typhimurium TA98 without S9 mix. But 1-substituted-2,4-dinitrobenzene derivatives which are substituted by electron-releasing groups such as hydroxyl amino or methyl (ie, 2,4-dinitrotoluene) did not show mutagenicity in Salmonella typhimurium TA98 without S9 mix. [Furukawa H et al; Nucleic Acids Symp Ser 16: 5-8 (1985)]**PEER REVIEWED**
  
• Subchronic and chronic toxicities of 2,4-DNT were evaluated in CD-1 mice. 2,4-DNT was more toxic to males than to females. Male mice fed 47 mg/kg per day or 137 mg/kg per day for 13 weeks gained less weight. However, females fed 52 or 147 mg/kg per day had no adverse effects. Feeding of 413 mg/kg per day for males or 468 mg/kg per day forfemales lowered feed consumption, depressed body weight, and caused mild anemia and mild hepatocellular dysplasia in both sexes and mild testicular degeneration in males. Both males and females were fed an average of 14 (low dose), 95 (middle dose), or 898 mg/kg/day (high dose) for up to 24 months. In males, there was high incidence of epithelial renal tumor and hepatocellular dysplasia in all dose groups. Incidence of testicular atrophy was increased in the middle and high-dose males. In addition, the high dose caused toxic anemia and death. In females, the high dose was associated with toxic anemia, hepatocellular dysplasia, nonfunctional follicle with a lack of corpora lutea, an effect analogous to the testicular atrophy in males, and death. [Hong CB et al; J Am Coll Toxicol 4 (4): 257-70 (1985)]**PEER REVIEWED**
  
• Adult Sprague Dawley rats were gavaged with 2,4-DNT dissolved in corn oil at 0, 60, 180, or 240 mg/kg/day for five days. A single oral dose (0.5 mg/kg) of triethylenemelamine was used as a positive control. Induction of dominant lethal events was scored on the basis of early fetal deaths. At the two lower doses, no consistent changes were observed in the numbers of pre-implantation losses, implantation sites, or living or non-living fetuses. The highest dose of 2,4-DNT tested resulted in a marked decrease in the numbers of sperm-positive females (determined by microscopic examination of vaginal smears for sperm) and pregnant females. These two effects diminished in the latter weeks of mating. The low number of pregnant females at the highest dose made meaningful statistical evaluations difficult. The results indicate that 2,4-DNT does adversely affect reproductive performance. [Lane RW et al; Drug Chem Toxicol 8 (4): 265-80 (1985)]**PEER REVIEWED**
  
• Subchronic and chronic toxicities of 2,4-dinitrotoluene were studied in CD-1 rats. Feeding of 2,4-dinitrotoluene for 13 weeks at a low dose of 34 mg/kg/day in males and 38 mg/kg/day in females caused depressed weight gain. The middle dose of 93 and 108 mg/kg/day, respectively, was toxic, caused reticulocytosis and splenic hemosiderosis, and decreased spermatogenesis. The high dose of 266 and 145 mg/kg/day, respectively, was more toxic and lethal. Some rats had widespread and stiff-legged gaits and demyelination in the cerebellum and brain stem. After feeding up to 2 years, the low dose (0.57 and 0.71 mg/kg/day, respectively) caused no apparent toxic effects. The middle dose (3.9 and 5.1 mg/kg/day, respectively) was toxic; the high dose (34 and 45 mg/kg/day) was more toxic and shortened the life span. Target organs included the blood (toxic anemia), the liver (hepatocellular carcinoma), the testis (atrophy and depression of spermatogenesis), the connective tissue in males (fibromas), and the mammary tissue in females (fibroadenomas). [Lee CC et al; J Am Coll Toxicol 4 (4): 243-56 (1985)]**PEER REVIEWED**
  
• 2,4-DNT and its urinary metabolites 2-amino-4-nitrotoluene, 4-amino-2-nitrotoluene, 2,4-diaminotoluene, 2,4-dinitrobenzyl alcohol, 2-amino-4-nitrobenzyl alcohol, 4-amino-2-nitrobenzyl alcohol, 2-nitro-4-acetylaminotoluene, 2-amino-4-acetylaminotoluene, 2-amino-4-acetylaminobenzoic acid, 2,4-dinitrobenzoic acid and 2,4-dinitrobenzaldehyde, an intermediate in the oxidation of 2,4-dinitrobenzyl alcohol to 2,4-dinitrobenzoic acid, were tested for mutagenicity in Salmonella typhimurium strains TA98 and TA100 in the absence or presence of S9 mixture. 2,4-DNT itself was only a weak mutagen. [Mori M et al; Chem Pharm Bull 33 (10): 4556-63 (1985)]**PEER REVIEWED**
  
• A single administration of either technical grade dinitrotoluene or 2,6-dinitrotoluene (75 mg/kg, orally), in combination with partial hepatectomy, initiated hepatocytes in rats when assayed using hepatic initiation-promotion protocols. Five other dinitrotoluene isomers (2,3-; 2,4-; 2,5-; 3,4-; and 3,5-DNT) evaluated similarly exhibited no such potential. [Leonard TB et al; Carcinogenesis 4 (8): 1059-61 (1983)]**PEER REVIEWED**
  
• A 2 year bioassay demonstrated the potent hepatocarcinogenicity of technical grade dinitrotoluene which contains 76% 2,4-dinitrotoluene, 18% 2,6-dinitrotoluene and less than 3% of each 2,3; 2,5; 3,4 and 3,5-dinitrotoluene isomers. In contrast, a 2 year bioassay of 2,4-dinitrotoluene did not result in the appearance of hepatic neoplasms above the spontaneous incidence. Weak hepatocyte initiating activity was identified in technical grade dinitrotoluene and purified 2,6-dinitrotoluene. In contrast, 2,3; 2,4; 2,5; 3,4 and 3,5 isomers had no detectable initiating activity. When fed following a diethylnitrosamine initiating regimen, technical grade dinitrotoluene, purified 2,4 and 2,6-dinitrotoluene isomers had demonstrable promoting activity. The hepatic neoplasms resulting from technical grade dinitrotoluene feeding apparently resulted from the initiating activity of 2,6-dinitrotoluene followed by the promoting effect of both the 2,4 and 2,6-dinitrotoluene isomers. The lack of hepatic neoplasms following chronic feeding of 2,4-dinitrotoluene was apparently due to the lack of hepatic initiating activity. [Popp JA, Leonard TB; Toxicol Pathol 10 (2): 190-6 (1982)]**PEER REVIEWED**
  
• The induction of unscheduled DNA synthesis by the potent hepatocarcinogen technical grade dinitrotoluene (76% 2,4-DNT, 19% 2,6-DNT) was examined by using the in vivo/in vitro hepatocyte DNA repair assay. Male Fischer-344 rats were treated by gavage and hepatocytes were isolated by liver perfusion and cultured with (3)H thymidine. Unscheduled DNA synthesis was measured by quantitative autoradiography as net grains per nucleus; 5 net grains per nucleus was considered positive. Controls consistently had -3 to -6 net grains per nucleus. A dose related increase in unscheduled DNA synthesis was observed 12 hr after treatment, with 200 mg/kg technical grade dinitrotoluene producing 26 net grains per nucleus. A 50 fold increase in the number of cells in S-phase was observed at 48 hr after treatment. This increase in S-phase cells could be suppressed in the presence of 10-20 mM hydroxyurea, while the same levels of hydroxyurea did not affect the level of unscheduled DNA synthesis at 12 hr after treatment. 2,4-DNT produced only a weak response, in contrast to 2,6-DNT which was a potent inducer of unscheduled DNA synthesis. Treatment of female rats with technical grade dinitrotoluene yielded only modest increases in unscheduled DNA synthesis and DNA replication relative to males. These results are consistent with the carcinogenicity studies and indicate that technical grade dinitrotoluene is a potent genotoxic agent, with 2,6-DNT contributing the major portion of the effect. [Mirsalis JC, Butterworth BE; Carcinogenesis 3 (3): 241-6 (1982)]**PEER REVIEWED**
  
• 2,4,6-Trinitrotoluene and pure 2,4-DNT gave positive responses in the P388 mouse lymphoma gene mutation assay in the absence of auxiliary metabolic activation. Both chemicals gave negative results when an activation system was included. Technical grade DNT (consisting of an 80:20 mixture of 2,4- and 2,6-DNT) and pure 2,6-DNT gave negative responses in the assay both in the presence and absence of auxiliary metabolism. [Styles JA, Cross MF; Cancer Lett 20 (1): 103-8 (1983)]**PEER REVIEWED**
  
• The mutagenicity of technical grade 2,4-DNT and the 6 isomers of DNT was determined in 3 assays with Salmonella typhimurium. The mixture and the individual isomers of DNT were found to be mutagenic in the Ames Salmonella microsome test, particularly in strains responding to frame-shift mutagens; 3,5-DNT was the most effective isomer in inducing reversion to histidine prototrophy in Salmonella typhimurium strain s TA98 and TA1538. Similar results were obtained with a quantitative reversion assay using strain TA98; 3,5-DNT was the most mutagenic of the compounds examined, particularly in the absence of post-mitochondrial supernants of rat-liver homogenates. While all isomers and the mixture of DNT increased the 8-azaguanine resistant fraction of Salmonella typhimurium TM677 to some degree, the greater mutagenicity of 3,5-DNT compared to other isomers was not evident in the forward mutation assay. [Couch DB et al; Mutat Res 90 (4): 373-84 (1981)]**PEER REVIEWED**
  
• 2,4-Dinitrotoluene (DNT) was tested for the induction of sex-linked recessive mutations in Drosophila melanogaster using a standard protocol approved by the National Toxicology Program. Canton-S wild-type males were treated with concentrations of DNT that resulted in approximately 30% mortality and were mated individually to 3 harems of Basc virgin females to produce 3 broods for analysis. DNT was positive at dose of 10,000 ppm when administered to males by injection. [Woodruff RC et al; Environ Mutagen 7: 677-702 (1985)]**PEER REVIEWED**
  
• Repeated in vivo exposure of rats to 2,4- ... dinitrotoluene is associated with dysplasia and rearrangement of aortic smooth muscle cells. [Klaassen, C.D., M.O. Amdur, Doull J. (eds.). Casarett and Doull's Toxicology. The Basic Science of Poisons. 5th ed. New York, NY: McGraw-Hill, 1995., p. 517]**PEER REVIEWED**
  
• Technical dinitrotoluene fed to rats induced liver cancer, but pure 2,4-dinitrotoluene was much less active. Attention was drawn to the 2,4-isomer, because of the known liver carcinogenicity of 2,4-diaminotoluene. However, examination of the potential to initiate hepatocellular altered foci showed that 2,6-dinitrotoluene, present in the technical product to about 20 percent, was much more active than the 2,4-isomer. [Amdur, M.O., J. Doull, C.D. Klaasen (eds). Casarett and Doull's Toxicology. 4th ed. New York, NY: Pergamon Press, 1991., p. 177]**PEER REVIEWED**
  
• 2,4-Dinitrotoluene ... has been shown to be a hepatocarcinogen in the rat. [International Labour Office. Encyclopedia of Occupational Health and Safety. Vols. I&II. Geneva, Switzerland: International Labour Office, 1983., p. 1452]**PEER REVIEWED**
  
• The toxic reproductive effects of the chemosterilant 2,4-dinitrotoluene were evaluated in the rat. Male Sprague Dawley rats were fed 0, 0.1, or 0.2% 2,4-DNT for a period of 3 weeks. Blood samples were collected for assessment of luteinizing hormone, follicle stimulating hormone, and testosterone levels prior to sacrifice. Testes and epididymides were then removed for ultrastructural evaluation and sperm reserve counts. 2,4-DNT exposure at a concentration of 0.2% was associated with a marked change in Sertoli cell morphology. No Leydig cell changes were detected. Alterations induced by 2,4-DNT included varying sized vesicles associated with swollen mitochondria and distended endoplasmic reticulum, increased levels of circulating luteinizing hormone and follicle stimulating hormone, reduced weights of epididymides, and decreased epididymal sperm reserves (63% reduction in animals treated with 0.2% 2,4-DNT). Testosterone levels were unaffected by 2,4-DNT. Sperm concentrations and serum hormone levels were not significantly affected by 0.1% 2,4-DNT. It was concluded that 2,4-DNT can induce testicular injury, directly or indirectly disturb pituitary function, and exert a toxic effect at late stages of spermatogenesis. The Sertoli cell may be a locus of 2,4-DNT induced inhibition of spermatogenesis and altered testicular/pituitary endocrine function. [Bloch E et al; Toxicol Appl Pharmacol 94 (3): 466-72 (1988)]**PEER REVIEWED**
  
• The mutagenicity of 19 nitro compounds was tested in a modified Ames/Salmonella assay with or without a preincubation step in which they were incubated for 30 minutes with an S9 mix containing flavin mononucleotide before testing. (TA-98) and (TA-100) were the tester strains. 2,4-Dinitrotoluene was mutagenic in the modified assay. [Dellarco UL, Prival MJ; Environ Mol Mutagen 13 (2): 116-27 (1989)]**PEER REVIEWED**
  
• The effects of four isomers of dinitrotoluene and technical dinitrotoluene (a mixture of dinitrotoluene isomers and other compounds, with 2,4-DNT as the major constituent) were studied in two short-term in vitro assays. None of the isomers or technical dinitrotoluene induced an increase in morphological transformation of Syrian hamster embryo cells. Four dinitrotoluene metabolites (2,4-diaminotoluene, 2-amino-4-nitrotoluene, 2-amino-6-nitrotoluene, and 2,4-dinitobenzoic acid), representing different stages in reduction or oxidation of dinitrotoluene isomers, were also negative for induction of morphological transformation. The dinitrotoluene isomers were tested in an intercellular communication assay based on dye transfer, 2,4-DNT, 2,6-dinitrotoluene, and technical dinitrotoluene inhibited intercellular communication in the Syrian hamster embryo cell line BPNi at toxic concentrations. This may be reminiscent of in vivo data showing promoting activity of these compounds. 2,3-Dinitrotoluene and 3,4-dinitrotoluene did not inhibit communication. [Holen I et al; J Toxicol Environ Health 29 (1): 89-98 (1990]**PEER REVIEWED**
  
• The hepatocyte foci promoting activity of 2,4-DNT and 2,6-DNT after initiation with diethylnitrosamine was studied in rats. Male Fisher 344 rats were initiated with a single ip 0 or 150 mg/kg dose of diethylnitrosamine. After a 2 week recovery period, they were fed diets containing 0 or 0.47% 2,4-DNT, 0.06, 0.12, or 0.24% 2,6-DNT, 0.2 or 0.55% technical grade dinitrotoluene, or 0.5% phenobarbital. Animals fed technical grade dinitrotoluene were killed after 3 or 6 weeks, and those given 2,4-DNT, 2,6-DNT, and phenobarbital after 6 or 12 weeks of feeding. Liver sections were stained for gamma glutamyl transferase. Number of positive gamma glutamyl transferase foci per cubic centimeter and mean volume of the foci were determined. Technical grade dinitrotoulene caused a dose dependent increase in gamma glutamyl transferase foci. 2,4-DNT and phenobarbital induced time dependent increases in positive gamma glutamyl transferase foci. 2,6-DNT induced both dose and time dependent increases in gamma glutamyl transferase foci. Feeding of 2,6-DNT alone for 12 weeks produced a large number of foci similar to that seen in animals given diethylnitrosamine plus the high dose high dose of 2,6-DNT. Mean foci volume was increased in animals fed 0.24% 2,6-DNT, relative to the other groups. It was concluded that technical grade dinitrotoluene, 2,4-DNT, and 2,6-DNT have hepatocyte foci promoting activity, and 2,6-DNT is approximately ten times more potent than 2,4-DNT. Combined with results of previous studies, data indicate that 2,6-DNT is a complete hepatocarcinogen, while 2,4-DNT is a pure promoter. Hepatic initiation promotion protocols are useful tools for investigating, initiating, and promoting properties of both complex mixtures and individual compounds. [Leonard TB et al; Carcinogenesis 7 (11): 1797-1803 (1986)]**PEER REVIEWED**
  
• The mutagenicity and carcinogenicity of chemicals previously identified as false positives in the Salmonella typhimurium mutagenicity assay were reevaluated using more stringent criteria than had been used in prior studies. The purpose of testing was to determine if the specificity of the assay could be enhanced by altering the criteria for distinguishing positive from negative chemicals. While the use of more stringent criteria resulted in a substantial reduction in the frequency of false positives in the mutagenicity assay, it also substantially reduced the frequency of true positives. The carcinogenicity data created more difficulties and uncertainties than did the mutagenicity data; of 25 chemical compounds previously cited as false positives, two were reevaluated as noncarcinogenic, two were carcinogenic, and the remaining 21 could not be classified because of the results of the rodent carcinogenesis bioassays or flaws in their design. 2,4-DNT was reclassified as carcinogenic. [Prival MJ, Dunkel VC; Environmental and Molecular Mutagenesis 13: 1-24 (1989)]**PEER REVIEWED**
  
• Sprague Dawley rats were injected ip 5 days/wk for 8 wk with either 2,4-DNT or 2,6-DNT at 0.5, 5, or 10 mg/kg or with medium chain triglyceride oil. Dysplasia and rearrangement of smooth muscle cells occurred at all doses tested as revealed through histopathologic evaluation of aortae. Primary cultures of aortic smooth muscle cells from dinitrotoluene exposed animals demonstrated reduced thymidine incorporation. No change was noted in the extent of thymidine incorporation in cycling or growth arrested cultures following exposure of smooth muscle cells from naive animals to dinitrotoluene in vitro in a range of concn from 1 to 100 micromolar. Replicative DNA synthesis was inhibited and unscheduled DNA synthesis stimulated in cyclic and growth arrested cultures of smooth muscle cells exposed to 2,4-diaminotoluene or 2,6-diaminotoluene, respectively. It was concluded that the development of vascular lesions is aided by the modulation of DNA synthesis in aortic smooth muscle cells by dinitrotoluene metabolites generated in vivo. [Ramos KS et al; Cell Biol Toxicol 7 (2): 111-128 (1991)]**PEER REVIEWED**
  
• In a screening assay based on increased multiplicity and incidence of lung tumors in a strain of mice highly susceptible to the development of this neoplasm, groups of 52 or 53 male and female strain A mice, six to eight weeks old, were given thrice weekly intraperitoneal injections of 2,4-dinitrotoluene (at a purity of 92-95%, with the major impurity being 2,6-dinitrotoluene) in tricaprylin for eight weeks (total doses, 0, 600, 1500 and 3000 (MTD) mg/kg body weight). Surviving mice were killed 22 weeks after the last injection and lung tumors appearing grossly were counted. Survival was 52/52 in controls, 52/53 at the low dose, 52/52 at the mid dose and 50/52 at the high dose. There was no increase in lung tumor incidence or in the number of lung tumors per mouse when compared to controls. The incidence of lung tumors in surviving mice was 29% in controls, 44% at the low dose, 19% at the mid dose and 26% at the high dose. [IARC. Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Man. Geneva: World Health Organization, International Agency for Research on Cancer, 1972-PRESENT. (Multivolume work)., p. V65 323 (1996)]**PEER REVIEWED**
  
• Several chronic toxicity studies in laboratory animals have shown that 2,4- ... dinitrotoluene can cause cancers of the liver, gallbladder, and kidney as well as benign tumors of the connective tissues. [Klaassen, C.D., M.O. Amdur, Doull J. (eds.). Casarett and Doull's Toxicology. The Basic Science of Poisons. 5th ed. New York, NY: McGraw-Hill, 1995., p. 517]**PEER REVIEWED**
  
• In animals ... central nervous system, reproductive, and bone marrow abnormalies have been noted. [Sullivan, J.B. Jr., G.R. Krieger (eds.). Hazardous Materials Toxicology-Clinical Principles of Environmental Health. Baltimore, MD: Williams and Wilkins, 1992., p. 536]**PEER REVIEWED**
  
• 2,4-Dinitrotoluene is an animal carcinogen. Tests for mutagenic activity of this compound are ambiguous. [Sullivan, J.B. Jr., G.R. Krieger (eds.). Hazardous Materials Toxicology-Clinical Principles of Environmental Health. Baltimore, MD: Williams and Wilkins, 1992., p. 536]**PEER REVIEWED**
  
• Technical grade DNT, (78% 2,4-DNT and 19% 2,6-DNT) positive control, or vehicle control were administered daily by gavage to timed-pregnant Fischer 344 rats (179 females total) on gestational days 7 through 20 or from gestational days 7 through parturition. Treatment with DNT (14, 35, 37.5, 75, 100, or 150 mg/kg/day, by gavage) resulted in mortality rates of 4.5% (1/22), 7.7% (1/13), 0.0% (0/22), 0.0% (0/13), 4.3% (1/23) and 46.2% (6/13), respectively, through gestational day 20. On gestational day 20, DNT treated dams exhibited /hematological changes/ as well as a dose related elevation of organ/body weight ratios for maternal liver and spleen, and a dose related decrease in absolute weight gain (ie, weight gain during gestation minus gravid uterine weight). Evidence of fetal toxicity was a profile for one or more treatment groups, but these effects were not dose related. Dosages of DNT which produced maternal and fetal toxicity failed to produce a teratogenic effect in Fischer 344 rats. Signs of DNT toxicity were reversed by postnatal day 30 for dams and by postnatal day 60 for pups. [Chem Indus Inst of Tox Report: Final Report: Teratological and Postnatal Evaluation of Dinitrotoluene in Fischer 344 Rats Docket # 10992 p.10-14 (1982)]**PEER REVIEWED**
  
• Rat Sertolior Sertoli germ cell cocultures were treated, after 3 days in culture, with dinitrotoluene isomers /2,3-, 2,4-, 2,6-, and 3,4-dinitrotoluene/ (0.01 to 100 uM) or 1,3-dinitrobenzene for 24 hr. Cellular morphology, germ cell detachment and lactate pyruvate production were used as sensitive effect markers of in vitro toxicity. Morphologically the Sertoli cell monolayer remained intact 24 hr after exposure to DMSO, 1,3-dinitrobenzene, or dinitrotoluene isomers. Some apparent cytotoxicity was observed at 100 uM 3,4-dinitrotoluene: the monolayer was disrupted with extensive vacuolation of the Sertoli cells. Cocultures treated with concn of 50 uM dinitrotoluene isomers closely resembled cells treated with 100 uM 1,3-dinitrobenzene. Germ cell detachment increased in a dose-dependent manner (0.01 and 10 uM dinitrotoluene isomers) increasing between 2- and 10-fold over control. Both lactate and pyruvate production increased with rising concn of dinitrotoluene isomers. The most sensitive effect was seen with 3,4-dinitrotoluene (10 to 25 uM). In the case of 2,6-dinitrotoluene, despite increases in germ cell detachment and lactate production, only a minimal increase in pyruvate was demonstrated. Overall, the ratio of lactate to pyruvate production declined with increase in doses of dinitrotoluene. These results indicate that the four isomers of dinitrotoluene directly affected Sertoli cells morphology and function, effects comparable to those seen with the Sertoli cell toxicant 1,3-dinitrobenzene. Further, the data support the hypothesis that dinitrotoluene may be a Sertoli cell toxicant. [Reader SC, Foster P; Toxicol Appl Pharmacol 106 (2): 287-94 (1990)]**PEER REVIEWED**
  
• A number of nitroaromatic explosives and related compounds were examined for mutagenic activity with the Salmonella/mammalian microsome test. All the nitroaromatics, except 2,4,6-trinitrophenol and 2,4,6-trinitroresorcinol, were at least an order of magnitude more mutagenic than 2,3-, 2,4-, and 2,6-dinitrotoluene. The most active compd was 2,3,5-trinitronaphthalene, which was approximately 5000 times more mutagenic than the dinitrotoluene isomers. [Whong WZ, Edwards GS; Mutat Res 136 (3): 209-15 (1984)]**PEER REVIEWED**
  
• The ability of 2,4-diaminotoluene, technical grade 2,4-dinitrotoluene (2,4-DNT), and the purified isomers 2,3-DNT, 2,4-DNT, 2,5-DNT, 2,6-DNT, 3,4-DNT, and 3,5-DNT to damage the DNA of primary rat hepatocytes was examined. Male rats were perfused in situ, single cell suspensions were obtained after liver dissociation, and cultures of the cells were treated in the presence of (3)H thymidine. Autoradiography was employed to visualize label incorporation following repair of DNA. At the nontoxic doses of less than or equal to 1X10-4 M, only 2,4-diaminotoluene induced a response. The carcinogenic activity of the dinitrotoluenes was not reflected as DNA repair in the isolated hepatocyte. [Bermudez E et al; Environ Mutagen 1 (4): 391-8 (1979)]**PEER REVIEWED**
  
• 2,6-DNT is a potenthepatocarcinogen in Fischer 344 rats, whereas 2,4-dinitrotoluene is believed to be noncarcinogenic. Neither 2,6-DNT nor 2,4-dinitrotoluene is carcinogenic in the strain A mouse lung bioassay. The ip administration of 2,6-DNT or 2,4-dinitrotoluene (150 mg/kg each) to Fischer 344 rats resulted, after 24 hr, in covalent binding to DNA of the liver (131.1 to 259.9 pmol 2,6-DNT/mg DNA; 215.4 to 226.8 pmol 2,4-dinitrotoluene/mg DNA), and lower binding to DNA of the lung and the intestine (14.9 to 22.7 pmol 2,6-DNT/mg DNA; 45.0 to 75.0 pmol 2,6-DNT/mg DNA). Similar treatment of A/J mice resulted in lower binding in the liver (25.9 to 31.9 pmol 2,6-DNT/mg DNA; 42.6 to 58.9 pmol 2,4-dinitrotoluene/mg DNA), no detectable binding of 2,6-DNT in extrahepatic tissues and low amounts of binding of 2,4-dinitrotoluene to lung and intestinal DNA (9.7 to 39.0 pmol/mg DNA). Covalent binding of the noncarcinogenic isomeric 2,4-dinitrotoluene to DNA of various tissues of both species suggests that factors other than binding to DNA determine the ultimate carcinogenic effect of these cmpd. [Dixit R et al; Toxicol Appl Pharmacol 82 (1): 53-61 (1986)]**PEER REVIEWED**
  
• The ability of a series of compounds from different chemical classes to induce lung tumors was compared in strain A/J mice after either ip or oral administration. 2,4-Dinitrotoluene, 2,6-dinitrotoluene, and a 2:1 mixture of 2,4-dinitrotoluene and 2,6-dinitrotoluene were inactive by both routes of administration and at all dose levels. [Stoner GD et al; Toxicol Appl Pharmacol 72 (2): 313-23 (1984)]**PEER REVIEWED**
  
• Multistage hepatocarcinogenic models were used to evaluate the relative initating and promoting properties of dinitrotoluene isomers. Male Fischer 344 rats were administered 75 mg/kg technical grade dinitrotoluene mixture containing 76.5% 2,4-dinitrotoluene (2,4-dinitrotolune), 18.8% 3,4-dinitrotoluene (1.54% 2,3-dinitrotoluene, 0.69% 2,5-dinitrotoluene, and 0.04% 3,5-dinitrotoluene, or one of the six isomers, as initating agents 12 hours after partial hepatectomy. Only technical grade dinitrotoluene mixture and 2,6-dinitrotoluene had significant initiating ability. The promoting abilities of 2,6-dinitrotoluene and 2,4-dinitrotoluene were tested by administration in the diet to animals in which the carcinogenic process had been initiated with diethylnitrosamine. Both 2,4-dinitrotoluene and 2,6-dinitrotoluene had promoting ability, but 2,6-dinitrotoluene was a more potent promoter. Male Fischer 344 rats were fed daily diets containing 35 mg/kg technical grade dinitrotoluene mixture, 27 mg/kg 2,4-dinitrotoluene or 7 mg/kg 2,6-dinitrotoluene for a period of 1 year. The 2,6-dinitrotoluene isomer induced hepatocellular carcinoma in twice as many animals as did technical grade dinitrotoluene mixture, and 2,4-dinitrotoluene was not hepatocarcinogenic at all. /It was/ concluded that 2,6-dinitrotoluene is a complete carcinogen, capable of both initiation and promotion, while 2,4-dinitrotoluene acts as a promoter of the carcinogenic process, but is not capable of initiating it, and the hepatocarcinogenicity of technical grade dinitrotoluene mixture is mainly due to 2,6-dinitrotoluene. [Goldsworthy TL, Popp JA; CIIT Activities 6 (12): 1-2/5-6 (1986)]**PEER REVIEWED**
  

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Human Toxicity Values

• None found

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Non-Human Toxicity Values

• Toxic dose Dog oral 1 mg/kg; Toxic effects: Inhibition of muscular coordination in the hind legs; Rigidity in extension of the hind legs; Decreased appetite; Weight loss ... . [USEPA; Ambient Water Quality Criteria Doc: Dinitrotoluene p.C-25 (1980) EPA 440/5-80-045]**PEER REVIEWED**
  
• LD50 Rat oral 268 mg/kg [Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996., p. 1387]**PEER REVIEWED**
  
• LD50 Mouse oral 790 mg/kg [Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996., p. 1387]**PEER REVIEWED**
  
• LD50 Guinea pig oral 1300 mg/kg [Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 9th ed. Volumes 1-3. New York, NY: Van Nostrand Reinhold, 1996., p. 1387]**PEER REVIEWED**
  

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Absorption, Distribution and Excretion

• AFTER SINGLE ORAL ADMIN OF (3)H 2,4-DNT TO RATS, RADIOACTIVITY IN BLOOD REACHED MAX 6 HR AFTER ADMIN WITH A HALF-LIFE OF APPROX 22 HR, MAX LEVEL IN LIVER OCCURRED AFTER 6 HR. ABOUT 10% EXCRETED INTO BILE WITHIN 24 HR. FECAL EXCRETION MAX 6-9 HR & URINARY WAS MAX 6 HR AFTER ADMIN. [MORI M ET AL; RADIOISOTOPES 27 (12): 715 (1978)]**PEER REVIEWED**
  
• IN STRAIN A MICE, THE URINE WAS THE MAJOR ROUTE OF ELIMINATION FOR 2,4-DINITROTOLUENE (2,4-DNT), WITH 52.5, 60.1, AND 70.0% OF IP DOSES OF 1, 10, AND 100 MG/KG, RESPECTIVELY, EXCRETED WITHIN 4 HR AFTER ADMIN. AT ALL DOSES RAPID AND EXTENSIVE METAB BY THE LIVER AND SMALL INTESTINE WAS OBSERVED. [SCHUT HA J ET AL; TOXICOL APPL PHARMACOL 64 (2): 213-20 (1982)]**PEER REVIEWED**
  
• THE CHANGE IN THE URINARY AND FECAL EXCRETIONS AND DISTRIBUTION OF (3)H LABELED 2,4-DNT IN RATS INGESTING A 0.5% 2,4-DNT DIET FOR 4 MO WAS STUDIED. EXCRETION AND DISTRIBUTION STUDIES SHOWED THAT THE LIVER, SKIN, AND THE ADIPOSE TISSUE ACCUMULATED THE UNCHANGED 2,4-DNT AND/OR ITS METABOLITES. [MORI M ET AL; RADIOISOTOPES 29 (7): 338-40 (1980)]**PEER REVIEWED**
  
• Excretion of dinitrotoluene in excess of 25 mg/l indicates significant absorption /in industrial exposed populations/. /Dinitrotoluene/ [Mackison, F. W., R. S. Stricoff, and L. J. Partridge, Jr. (eds.). NIOSH/OSHA - Occupational Health Guidelines for Chemical Hazards. DHHS(NIOSH) Publication No. 81-123 (3 VOLS). Washington, DC: U.S. Government Printing Office, Jan. 1981., p. 1]**PEER REVIEWED**
  
• The elimination and metabolism of a single dose (100 mg/kg) of 2,4-dinitrotoluene (2,4-DNT) in A/J mice were examined. After ip administration, elimination was rapid, with 70% of the dose appearing in the urine within 4 hr. Four hours after oral administration, only 28.5% of the dose was excreted in the urine, which increased to 66% after 8 hr. Elimination via the feces was minimal (< 2.1% of the dose) in both cases. [Schut HA et al; Biochem Pharmacol 34 (7): 969-76 (1985)]**PEER REVIEWED**
  
• Two biological monitoring studies were carried out among workers in an explosives factory who were exposed to technical grade dinitrotoluene. In the first study, urine samples from 28 workers were analyzed for the metabolite 2,4-dinitrobenzoic acid. Metabolite concentrations in urine were extremely low or nondetectable, prior to starting work at the beginning of the working week, but post-shift urine samples contained a mean 2,4-dinitrobenzoic acid level of 17 mg/l. There were wide variations in the concentrations excreted in urine by different workers and by individual workers on consecutive days. Atmospheric levels of dinitrotoluene (determined by personal monitoring) were found to be well below the recommended limit and therefore could not account for the observed excretion of 2,4-dinitrobenzoic acid. Skin may be the major route of absorption of dinitrotoluene during this process. A second study was carried out to investigate the kinetics of absorption and excretion of dinitrotoluene. Intensive urine sampling was carried out on 5 individuals over a 2 day period with additional samples over the subsequent 2 nonworking days. Analysis for 2,4-dinitrobenzoic acid showed that uptake of dinitrotoluene is rapid and that the highest levels were normally seen in the end of shift specimens. Urine samples were analyzed for other known metabolites of dinitrotoluene which have been found in animal studies and it was shown that 2,4-dinitrobenzoic acid is the major known metabolite which is excreted in human urine. Unchanged dinitrotoluene was detected in blood samples taken during a single workshift at levels up to 250 ng/ml. [Woollen BH et al; Int Arch Occup Environ Health 55 (4): 319-30 (1985)]**PEER REVIEWED**
  

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Metabolism/Metabolites

• METAB OF (14)C-LABELED 2,4-DNT TO 2,4-DINITROBENZYL ALCOHOL BY POSTMITOCHONDRIAL LIVER FRACTION FROM RABBITS, DOGS & MONKEYS WAS GREATER THAN BY FRACTIONS FROM MICE & RATS. ONLY CONSISTENT SEX DIFFERENCE WAS FORMATION OF MORE AMINOTOLUENES BY MALE LIVERS FOLLOWING A NITROGEN FLUSH. [SHORT RD ET AL; EXPERIENTIA 35 (12): 1625 (1979)]**PEER REVIEWED**
  
• NINE METABOLITES OF 2,4-DINITROTOLUENE IN RAT URINE WERE DETECTED BY TLC AFTER REPEATED ORAL ADMIN TO MALE RATS. 2-AMINO-4-NITROTOLUENE, 4-AMINO-2-NITROTOLUENE, 2,4-DIAMINOTOLUENE, 2,4-DINITROBENZYL ALC, 2-AMINO-4-NITROBENZYL ALC, 4-AMINO-2-NITROBENZYL ALC, 2-NITRO-4-ACETYLAMINOTOLUENE, 2-AMINO-4-ACETYLAMINOTOLUENE, & 2-AMINO-4-ACETYLAMINOBENZOIC ACID WERE IDENTIFIED. [MORI M ET AL; CHEM PHARM BULL 29 (4): 1147-50 (1981)]**PEER REVIEWED**
  
• 2,4-DNT TREATMENT HAD LITTLE EFFECT ON THE ACTIVITY OF SOME HEPATIC XENOBIOTIC METABOLIZING ENZYMES IN RATS, AND WAS READILY METABOLIZED BY LIVER PREPN IN VITRO. THE PATHWAYS OF IN VITRO METABOLISM WERE DEPENDENT ON OXYGEN TENSION. THIS IN VITRO METAB PRODUCED MOSTLY POLAR METABOLITES WHICH DID NOT BIND APPRECIABLY TO MICROSOMAL MACROMOLECULES. [DECAD GM ET AL; TOXICOL APPL PHARMACOL 62 (6): 325-34 (1982)]**PEER REVIEWED**
  
• IN RATS, THE REDUCTIVE METABOLIC CAPACITY OF CECAL CONTENTS ON PER G WT BASIS EXCEEDS THAT BY LIVER MICROSOMES BY FACTOR OF 1000, SUGGESTING THAT CECUM REPRESENTS MAJOR SITE OF REDUCTIVE METABOLISM OF DNT. LIVER & CECAL MICROFLORA ACTING IN CONCERT REPRESENT MAJOR SITES FOR FORMATION OF DINITROTOLUENE METABOLITES WHICH MAY BE RESPONSIBLE FOR ITS CARCINOGENIC ACTIVITY. [DENT JG ET AL; ADV EXP BIOL 136A: 431 (1982)]**PEER REVIEWED**
  
• Bioactivation of dinitrotoluene in the rat is thought to occur by the following processes: The methyl group is oxidized to an alcohol by a cytochrome p450 dependent pathway; the benzyl alcohol is conjugated with glucoronic acid and excreted in the bile. Intestinal microflora hydrolyze the glucuronide and reduce one nitro group, forming an aminonitrobenzyl alcohol which can be readsorbed from the intestine. The amino group /is/ oxidized to an hydroxylamine by hepatic enzymes and conjugated with sulfate. Decomposition of the sulfate ester yields a highly electrophilic nitrenium (or carbonium) ion which can react with DNA and other biological nucleophiles. [Turner MJ; CIIT 6 (2): 1-3 (1986)]**PEER REVIEWED**
  
• The elimination and metabolism of a single dose (100 mg/kg) of 2,4-dinitrotoluene (2,4-DNT) in A/J mice were examined. From 0.5 to 4 hr after ip administration, 3.6 to 8.8% of the urinary metabolites was unconjugated while 2.4 to 8.8% was present in the glucuronide fraction. After oral administration these amounts were 5.5 to 6.8% and 20.5 to 28.2% respectively. After both ip and oral administration, no unchanged 2,4-DNT could be detected in the urine, and 2,4-dinitrobenzyl alcohol represented the most abundant identifiable neutral metabolite. Small amounts of 2,4-diaminotoluene, 2-amino-4-nitrobenzyl alcohol, 2-(N-acetyl)amino-4-nitrotoluene, 4-amino-2-nitrotoluene, and 2-amino-4-nitrotoluene were also present. In almost all cases the largest proportion of metabolites represented unknowns, some of which exhibited the chromatographic properties of carboxylic acid metabolites. Metabolism of 2,4-DNT by liver and lung microsomes yielded mainly 2,4-dinitrobenzyl alcohol with lower amounts of 4-amino-2-nitrotoluene and 2-amino-4-nitrotoluene, and their formation was dependent on the presence of oxygen and NADPH. Pretreatment of the animals with 2,3,7,8-tetrachlorodibenzo-p-dioxin resulted in increased yields of all three metabolites. Aerobic metabolism of 2,4-DNT by explants of the small intestine, large intestine, or by fecal contents yielded 2,4-dinitrobenzyl alcohol, 2-amino-4-nitrotoluene, 4-amino-2-nitrotoluene 4-(N-acetyl)amino-2-nitrotoluene. The proportion of reduced metabolites (2-amino-4-nitrotoluene, 4-amino-2-nitrotoluene, and 4-(N-acetyl)amino-2-nitrotoluene) was much higher in these systems than with liver or lung microsomes and their formation by small intestine and cecal contents was enhanced several-fold under anaerobic conditions, while that of 2,4-dinitrobenzyl alcohol was abolished. [Schut HA et al; Biochem Pharmacol 34 (7): 969-76 (1985)]**PEER REVIEWED**
  
• ... Urine specimens were collected over 72 hr from workers at a dinitrotoluene manufacturing plant. Samples were analyzed for 2,4- and 2,6-DNT and putative metabolites by GC/MS. Urine from workers exposed to dinitrotoluene contained 2,4- and 2,6-DNT, 2,4- and 2,6-dinitrobenzoic acid, 2,4-and 2,6-dinitrobenzyl glucuronide, 2-amino-4-nitrobenzoic acid and (N-acetyl)amino-4-nitrobenzoic acid. The calculated half-times for elimination of total DNT-related material detected in urine ranged from 1.0-2.7 hr, and those of individual metabolites from 0.8-4.5 hr. The most abundant metabolites were 2,4-dinitrobenzoic acid and 2-amino-4-nitrobenzoic acid, collectively accounting for 74-86% of the dinitrotoluene metabolites detected. Urinary metabolites of dinitrotoluene in humans were qualitatively similar to those found in rats, but quantitative differences existed in the relative amounts of each metabolite excreted. [Turner MJ et al; Toxicol Appl Pharmacol 80 (1): 166-74 (1985)]**PEER REVIEWED**
  
• The pathways of metabolism of 2,4-dinitrotoluene (2,4-DNT) in the fecal microflora of rats were studied. 2,4-DNT was not metabolized by this preparation in the presence of oxygen. Under anaerobic conditions, an ordered sequence of reductive metabolism was observed. 2,4-DNT was reduced to 2-amino-4-nitrotoluene and 4-amino-2-nitrotoluene via 2-hydroxylamino-4-nitrotoluene and 4-hydroxylamino-2-nitrotoluene. The 2 aminonitrotoluenes were then reduced to 2,4-diaminotoluene. No intermediates in this sequence could be isolated. Thus, the rat intestinal microflora catalyze the reductive metabolism of 2,4-DNT and the reduction of 2,4-DNT to 2,4-diaminotoluene. [Mori M et al; Chem Pharm Bull 33 (10): 4556-63 (1985)]**PEER REVIEWED**
  
• Urinary metabolites of 2,4-DNT were quantitated by HPLC after administration to male Wistar rats. 2,4-Dinitrobenzoic acid was excreted most abundantly, followed by 2,4-dinitrobenzyl alcohol glucuronide, 2-amino-4-acetylaminobenzoic acid, 2,4-dinitrobenzyl alcohol, 4-amino-2-nitro(2-amino-4-nitro)benzyl alcohol glucuronides, 4-amino-2-nitrotoluene. Though 2,4-dinitrobenzaldehyde, a potent mutagen, was not detected, the oxidative conversion of 2,4-dinitrobenzyl alcohol to 2,4-dinitrobenzoic acid in vivo might be correlated to the carcinogenicity of 2,4-DNT, since 2,4-dinitrobenzoic acid and 2,4-dinitrobenzyl alcohol are the major metabolites of 2,4-DNT. [Shoji M et al; Chem Pharm Bull (Tokyo) 33 (4): 1687-93 (1985)]**PEER REVIEWED**
  
• The covalent binding to hepatic RNA, DNA and protein of a highly genotoxic DNT isomer, 2,6-DNT, was compared with that of a less genotoxic DNT isomer 2,4-DNT after oral administration to male Fischer-344 rats. Covalent binding to each macromolecular species was proportional to dose (10 or 35 mg/kg) for each isomer, but that due to 2,6-DNT was always 2 to 5-fold higher. There was no selectivity of either isomer for macromolecule. The time course of appearance and disappearance of covalently bound material was similar regardless of isomer or dose administered. Little covalently bound material was present until 8 hr after the dose. Covalent binding peaked between 12-24 hr and then slowly declined. The half-lives of covalently bound material were independent of the isomer administered, ranging from 2.9-5.0 days for RNA and protein and from 5.1-7.9 days for DNA. Both isomers disappeared from the small intestine rapidly, and covalently binding to hepatic macromolecules became significant only after the isomeric dinitrobenzyl alcohol glucuronides had appeared in the small intestine. The concentration of alcohol glucuronides in the intestine declined prior to peak covalent binding in the liver. Covalent binding to hepatic macromolecules qualitatively reflected the differences in genotoxicities between the 2 isomers. The time course of intestine disposition of the 2 isomers supported previous reports that suggested that activation of both isomers required oxidation to the corresponding benzyl alcohol, glucuronidation, excretion in the bile, deconjugation and further metabolism by intestinal microorganisms, followed by reabsorption. [Rickert DE et al; J Toxicol Environ Health 11 (4-6): 555-68 (1983)]**PEER REVIEWED**
  
• The metabolites produced from 5 DNT isomers (2,3-, 2,4-, 2,5-, 2,6- and 3,4-DNT) by Escherichia coli strain W3110, isolated from human intestine, were identified. Data obtained from metabolites produced by the Escherichia coli were 2 monoaminonitrotoluenes and hydroxylaminonitrotoluenes in all cases. This finding indicates that DNT is reduced via hydroxylaminonitrotoluenes to monoaminonitrotoluenes in Escherichia coli. In addn, the redn reactivities of DNT isomers were 3- > 2- for 2,3-DNT, 4- > 2- for 2,4-DNT, 5- > 2- for 2,5-DNT and 3- > 4- for 3,4-DNT. [Mori M et al; Chem Pharm Bull 32 (10): 4070-5 (1984)]**PEER REVIEWED**
  
• THE INCIDENCE OF HEPATOCELLULAR CARCINOMA IS HIGHER IN MALE RATS FED 35 MG 2,4-DINITROTOLUENE (2,4-DNT) THAN IN FEMALE RATS FED THE SAME DOSE. SEX DIFFERENCES IN 2,4-DNT DISPOSITION AND/OR METABOLISM MAY ACCOUNT FOR THIS DIFFERENCE. THE METABOLISM AND BILIARY EXCRETION OF 2,4-DNT IN MALE & FEMALE ISOLATED PERFUSED RAT LIVERS WERE STUDIED. OXIDATION OF 2,4-DNT TO 2,4-DINITROBENZYL ALCOHOL FOLLOWED BY GLUCURONIDATION TO 2,4-DINITROBENZYL GLUCURONIDE (DNBALCG) WAS THE MAJOR ROUTE OF METAB IN BOTH SEXES. AFTER PERFUSION WITH 20 UMOLAR, MALE LIVERS EXCRETED LARGER QUANTITIES OF 2,4-DINITROBENZYL GLUCURONIDE IN THE BILE (392 NMOLES) THAN FEMALE LIVERS (172 NMOLES); AT THE SAME 2,4-DNT CONCN, PERFUSATES FROM FEMALE LIVERS CONTAINED GREATER THAN 3 TIMES AS MUCH 2,4-DINITROBENZYL GLUCURONIDE AS MALE PERFUSATES. APPARENTLY, 2,4-DINITROBENZYL GLUCURONIDE IS TRANSPORTED INTO THE BILE @ SLOWER RATES IN FEMALES THAN IN MALE LIVERS. [BOND JA ET AL; J PHARMACOL EXP THER 219 (3): 598-603 (1981)]**PEER REVIEWED**
  
• The metabolism of 2,4-DNT was studied in vitro. 2,4-DNT was incubated with microsomal or cytosolic fractions of livers from male Sprague Dawley rats. In both liver preparations, 2,4-DNT was metabolized primarily to 2,4-dinitrobenzyl alcohol. Conversion of 2,4-DNT to 2,4-dinitrobenzyl alcohol was almost completely inhibited by nitrogen and SKF525A. A dose dependent inhibition occurred with carbon monoxide, 20, 50, and 80% in oxygen. It was concluded that hepatic oxidation of 2,4-DNT to 2,4-dinitrobenzyl alcohol is mediated by the cytochrome p450 system. [Shoji M et al; Chem Pharm Bull 35 (4): 1579-86 (1987)]**PEER REVIEWED**
  
• A series of 2,4-dinitrotoluene metabolites were prepared and analyzed using electron impact and chemical ionization mass spectrometry. Electron impact and chemical ionization mass spectra were used to determine the identifying characteristics of these metabolites. The differentiation of the isomers was made possible through electron impact ions which were characteristic to the position of the methyl group with regard to the nitro group and to the position of the carboxylic acid group with regard to the nitro group. Electron impact could be used to differentiate isomers. All metabolites containing acetylamino groups were characterized by a major loss of COCH2 (ketene group) from the molecular ion. Only in metabolites where a carboxylic acid was ortho to a nitro group was a loss of carbon dioxide from the molecular ion observed. [Yinon J; Biomed Environ Mass Spec 18 (3): 149-56 (1989)]**PEER REVIEWED**
  
• Hydrolyzed urine from workers exposed to dinitrotoluene contained 2,4- and 2,6-DNT, 2,4- and 2,6-dinitrobenzoic acid, 2,4- and 2,6-dinitrobenzyl alcohol, 2-amino-4-nitrobenzoic acid, and 2-(N-acetyl)amino-4-nitrobenzoic acid. ... The percentages of 2,4- and 2,6-DNT metabolites in the urine of individual subjects ranged from 79% to 93%. [Turner MJ; CIIT 6 (2): 3-4 (1986)]**PEER REVIEWED**
  
• The routes of formation of the intermediary metabolites of 2,6-dinitrotoluene were investigated in male Wistar rats. The urinary and biliary metabolites and hepatic metabolism of 2,6-dinitrotoluene, 2,6-dinitrobenzyl alcohol and 2,6-dinitrobenzaldehyde were examined. The intestinal metabolism of the bile from rats dosed with 2,6-dinitrotoluene was also studied. The major metabolite in the urine was conjugated 2,6-dinitrobenzyl alcohol, accounting for about 1.5% of the dose. The major metabolite in the bile of rats dosed with 2,6-dinitrotoluene was 2,6-dinitrobenzyl alcohol, accounting for 30% of the dose. Common biliary metabolites in rats dosed with 2,6-dinitrobenzyl alcohol or 2,6-dinitrobenzaldehyde were conjugates of the two cmpd. Incubating bile from rats given 2,6-dinitrotoluene with rat intestinal contents under nitrogen produced 2,6-dinitrobenzyl alcohol and 2,6-dinitrobenzaldehyde. Incubation of 2,6-dinitrotoluene with hepatic microsomal preparations gave 2,6-dinitrobenzyl alcohol. The authors conclude that 2,6-dinitrobenzaldehyde was produced as an intermediary metabolite of 2,6-dinitrotoluene either by oxidation of 2,6-dinitrotoluene in the liver or by oxidation of 2,6-dinitrobenzyl alcohol formed by hydrolysis of 2,6-dinitrobenzyl alcohol conjugates excreted in the bile. The enterohepatic circulation of 2,6-dinitrobenzyl alcohol and 2,6-dinitrobenzaldehyde wa demonstrated. These findings indicate that there are metabolic differences between 2,4-dinitrotoluene and 2,6-dinitrotoluene in male Wistar rats. [Mori M et al; Xenobiotica 19 (7): 731-41 (1989)]**PEER REVIEWED**
  
• An examination was made of the biliary metabolites of 2,4-dinitrotoluene), and 2,4-dinitrobenzyl alcohol and 2,4-dinitrobenzaldehyde in male Wistar rats using high performance liquid chromatography. The major biliary metabolite of 2,4-dinitrotoluene was 2,4-dinitrobenzyl-alcohol-glucuronide and the minor metabolites were 2,4-dinitrobenzyl alcohol, 2,4-dinitrobenzaldehyde, 2-acetylamino-4-nitrotoluene, 4-amino-2-nitro(2-amino-4-nitro)benzyl-alcohol-sulfate, 2,4-dinitrobenzoic acid, 2,4-diacetylaminobenzoic acid and 2-amino-4-nitrobenzoic acid. The bile of rats dosed with 2,4-dinitrobenzyl alcohol was shown to contain 2,4-dinitrobenzyl alcohol, 2,4-dinitrobenzaldehyde, 2,4-dinitrobenzyl-alcohol-glucuronide, and 4-amino-2-nitro(2-amino-4-nitro)benzyl-sulfate. The bile of rats dosed with 2,4-dinitrobenzaldehyde contained 2,4-dinitrobenzaldehyde, 2,4-dinitrobenzyl alcohol, 2,4-dinitrobenzyl-glucuronide, 4-amino-2-nitro(2-amino-4-nitro)benzyl-alcohol-sulfate and 2,4-diacetylaminobenzoic acid. The authors conclude that the common biliary metabolites of 2,4-dinitrotoluene, 2,4-dinitrobenzyl alcohol, and 2,4-dinitrobenzaldehyde were 2,4-dinitrobenzyl alcohol and its glucuronide, and 2-4-dinitrobenzaldehyde. The authors conclude that enterohepatic circulation of 2,4-dinitrobenzaldehyde was evident in the metabolism of 2,4-dinitrotoluene. [Sayama M et al; Xenobiotica 19 (1): 83-92 (1989)]**PEER REVIEWED**
  

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TSCA Test Submissions

• 2,4-Dinitrotoluene (CAS # 121-14-2) was evaluated for chronic toxicity and carcinogenicity in CD rats (38/sex/group) exposed to concentrations of 0, 15 (0.0015%), 100 (0.1%), and 700 ppm (0.7%) in the diet for up to 2 years. Dietary inclusion of 2,4-DNT at 700 ppm (0.7%) was associated with an average 2,4-DNT uptake of 34 mg/kg/day in males and 45 mg/kg/day in females, and with clinical toxicity including decreased weight gain and increased mortality (100% by Month 23). Death was attributed primarily to pituitary tumors, ulcerated subcutaneous tumors, and inanition. Behavior disturbances and motor dysfunction relative to dose were pathognostic and often attributable to pituitary dysfunction, including hyperexcitability, one-sided ataxia, and/or paralysis of the hindquarters or entire body. Histopathological assessment also revealed hepatocellular carcinoma and increased incidence of common background tumors in this strain of rat, with fibromas in the males and mammary fibroadenomas in the females. Pituitary chromophobe adenomas in both males and females were significantly decreased. An apparent hemolytic anemia, as evidenced by increased reticulocyte counts, also accompanied treatment, although evidence of methemoglobin, Heintz bodies, and lesions of the erythropoietic system was inconsistent. In males, 2,4-DNT also induced atrophy of seminiferous tubules with near complete lack of spermatogenesis in some cases. Mid-level animals (average intake 3.9 mg/kg/day males and 5.1 mg/kg/day females) exhibited similar if milder responses in susceptible individuals, while rats of a low level exposure were apparently free of toxic effects.[Miles Inc; Mammalian Toxicity of Munitions Compounds Phase III: Effects of Life-Time Exposure, Part 1: 2,4-Dinitrotoluene; 11/01/79; EPA Document No. 86940001004; Fiche No. OTS0557413]**UNREVIEWED**
  
• 2,4-Dinitrotoluene (CAS # 121-14-2) was evaluated for chronic toxicity and carcinogenicity in CD-1 mice (58/sex/group) exposed to concentrations of 100 (0.01%), 700 (0.07%), and 5,000 ppm (0.5%) in the diet for up to 2 years (average 2,4-DNT intakes of 13.5, 95, and 900 mg/kg/day, respectively). High-dose mice exhibited treatment-related toxicity beginning at Week 28, including low bodyweight, red-orange urine stains, hypoactivity, hunchback, hyperexcitability with stimuli, abnormal gait and muscular dysfunction, and nearly halved survival relative to the other treatment groups. Dietary inclusion of 2,4-DNT from 100 ppm was associated with consistently reduced bodyweights from Month 12, nephropathy, pigmentation (2,4-DNT metabolites or hemolytic deposits), liver dysplasia (mostly in males), increased intestinal pinworms, and unique renal tumors (males only). Treatment-related lesions were more extensive and numerous in mid-dose mice and included cystic renal tumors (over 50% in males), aspermatogenesis and testicular atrophy. High-dose females had nonfunctioning ovaries. Toxic anemia and appearance of Heinz bodies (signifying hemolytic activity) was noted primarily in moribund mid-dose males and high-dose males and females, nearly unanimous among high-dose animals. One-month recovery following 12 and 24-month dietary exposure indicated some amelioration of effects upon the blood. Furthermore, a lesser incidence of toxic anemia or methemoglobin among survivors of 24-month exposure suggested an adaptive or compensatory mechanism. Study authors offered that the lesser incidence of renal tumors in high-dose relative to the mid-dose mice probably reflected early deaths among the susceptible population. There was, however, greater incidence and severity of hepatocellular dysplasia and nephropathy in these animals.[Miles Inc; Mammalian Toxicity of Munitions Compounds Phase III: Effects of Life-Time Exposure, Part 1: 2,4-Dinitrotoluene; 11/01/79; EPA Document No. 86940001004; Fiche No. OTS0557413]**UNREVIEWED**
  
• 2,4-Dinitrotoluene (2,4-DNT, CAS # 121-14-2) was evaluated for chronic toxicity and carcinogenicity in beagle dogs (6/sex/group) fed daily doses of 0, 0.2, 1.5, and 10.0 mg/kg/day in capsules for up to 24 months. Repeated oral administration of 1.4 mg/kg (mid-level) 2,4-DNT and above was associated with effects on the erythrocytes, the biliary tract, the nervous system, and mortality. Increasing reticulocyte levels, Heinz bodies or methemoglobin (high-dose dogs only) were noted in mid- and high-dose animals after 12 months of treatment. All high-dose dogs (after Weeks 8-20, total dose 510-1,240 mg/kg) and 1 mid-level dosed dog (after Week 66, total dose 700 mg/kg) also exhibited neurological effects, documented as ataxia and/or incoordination and paralysis involving hindlimbs, trunk, neck, and control of lips and tongue. High-dose dogs continued to express neurologic symptoms up to the third quarter of treatment (18 months, total dose 2,730 mg/kg). All other mid-level dosed dogs remained free of overt toxicity throughout study (25 months, cumulative dose up to 1,092 mg/kg). Loss of bodyweight coincided with inability to eat or drink during those episodes causing oral motor dysfunction. Three high-dose dogs, euthanized due to severe paralysis, were found to have generalized endothelial vacuolization, hypertrophy and mitosis, and degenerative lesions of the cerebellum and brain stem. Encephalopathy was not identified in other dogs exhibiting neurotoxic signs, and the study authors concluded that biochemical lesions rather than microscopically visible histopathological lesions might be significant at lesser levels of toxicity. Administration of a barbiturate overdose for euthanasia relaxed the paralysis in all cases. Upon terminal necropsy, hyperplasia of both biliary tract and the gallbladder epithelium was found unresolved in affected male and female pairs of middle and high dose dogs sacrificed and necropsied at Months 13 and 25 after a 1-month cessation of treatment at 12 and 24 months, respectively. No other treatment-related lesions were identified and no effects on relative or absolute organ weights were noted at any treatment level at either assessment (12 or 24 months). Red blood cell effects noted early in treatment were only minimally apparent after 24 months in both mid- and high-dose dogs. Study authors suggested that a tolerance or compensatory ability after prolonged exposures may explain the diminution of treatment-associated effects on erythrocytes.[Miles Inc; Mammalian Toxicity of Munitions Compounds Phase III: Effects of Life-Time Exposure, Part 1: 2,4-Dinitrotoluene; 11/01/79; EPA Document No. 86940001004; Fiche No. OTS0557413]**UNREVIEWED**
  
• 2,4-Dinitrotoluene (CAS # 121-14-2) was evaluated for metabolic disposition in fasted CD rats (12/sex/group) previously exposed to concentrations of 0, 15 (0.0015%), 100 (0.1%), and 700 ppm (0.7%) in the diet. After 3, 9, or 20 months each group was fed single oral doses of 57 mg/kg (males) or 65 mg/kg (females) 2,4-DNT, spiked with 25 uCi/kg of DNT-(ring-UL-14C, specific activity 3.55 mCi/mM) and suspended in peanut oil, by oral gavage in a volume of 10 ml/kg bodyweight. Urine and feces were collected for 24 hours, after which all animals were sacrificed for collection of blood from the abdominal aorta and analysis of tissues for radioactivity. The sample was nearly wholly absorbed, a large portion returned in the urine after 24 hours with minor amounts appearing in the gastrointestinal tract and feces. Only a trace amount of radioactivity remained in the tissues, largely in the liver and kidney. The predominant metabolites were dinitro-, aminonitro-, and diaminobenzyl alcohols indicating oxidation of the side chain and reduction of nitro groups; very little unmetabolized 2,4-DNT was recovered. Conjugation products of these metabolites primarily constituted the total excreta. Because of morbidity and mortality among high-dose rats at the 20 months' scheduled gavage, extra mid-dose animals were used for the final analysis. No significant discrepancies in absorption, distribution, metabolism, or excretion values were noted between exposure groups, sexes, or terms of exposure.[Miles Inc; Mammalian Toxicity of Munitions Compounds Phase III: Effects of Life-Time Exposure, Part 1: 2,4-Dinitrotoluene; 11/01/79; EPA Document # 86940001004; Fiche No. OTS0557413]**UNREVIEWED**
  
• 2,4-Dinitrotoluene (CAS # 121-14-2) was evaluated for reproductive toxicity in CD rats (38 male and 58 females/group) exposed to concentrations of 0 ppm, 15 ppm (0.0015%), 100 ppm (0.1%), and 700 ppm (0.7%) in their diet for 6 months. Of this F0 generation, 10 males and 20 females randomly selected from the same dietary exposure group were then mated (1 male with 2 females) twice for 14 days, with 20-24/sex of a second F1 litter randomly selected for inclusion in continued study. This process repeated twice more, each successive generation was mated at 3 months of age and treated with 2,4-DNT at the same dosage as the parental generation until removed from study upon the weaning of their offspring. Treatment did not appear to effect fertility, liveborn index, birthweight, weight at weaning, or sex ratio. No treatment-related morphological abnormalities in the pups of 2,4-DNT exposed parents were observed. Two generations only of high-dose rats were available for study due to the toxic effects of 2,4-DNT toxicity on F0 and F1 parents, i.e. markedly diminished bodyweight (77% and 75% in males and 77% and 90% in females of F0 and F1 generations, respectively), debilitation, aspermatogenesis. The low numbers of F1 mated animals and a lack of F2 parents further indicated a decreased reproductive performance if not a direct reproductive effect. A reduction in mean litter size in the F1 generation did not persist in subsequent generations, but coincided with depressed viability and lactation indexes in offspring of F0 parents. Loss of pups was found to occur primarily during parturition, which may have been due to both the age and 2,4-DNT toxicity of F0 females upon a second mating.[Miles Inc; Mammalian Toxicity of Munitions Compounds Phase III: Effects of Life-Time Exposure, Part 1: 2,4-Dinitrotoluene; 11/01/79; EPA Document # 86940001004; Fiche No. OTS0557413]**UNREVIEWED**
  
• 2,4-Dinitrotoluene (CAS # 121-14-2) was evaluated for clastogenicity in CD rats (38/sex/group) exposed to concentrations of 0 ppm, 15 ppm (0.0015%), 100 ppm (0.1%), and 700 ppm (0.7%, average 2,4-DNT uptake 34 mg/kg/day in males and 45 mg/kg/day in females) in the diet for up to 2 years. Metaphase cells (200/culture for ploidy analysis) of peripheral blood lymphocytes (harvested at 1 year), bone marrow, and kidney cultures revealed slightly but significantly (Dunnett's multiple comparison procedure following an analysis of variance; p < 0.05) increased tetraploidy in kidney cultures harvested from middle dose (100 ppm) rats exposed for 2 years. Neither kidney nor bone marrow cultures from a solitary high dose rat surviving 2-year exposure showed any such effect. Furthermore, no morphological changes relative to control were noted in chromosomes of any culture (up to 50 cells/culture for chromosome morphological analysis) from any treatment group.[Miles Inc; Mammalian Toxicity of Munitions Compounds Phase III: Effects of Life-Time Exposure, Part 1: 2,4-Dinitrotoluene; 11/01/79; EPA Document # 86940001004; Fiche No. OTS0557413]**UNREVIEWED**
  
• 2,4-Dinitrotoluene (CAS # 121-14-2) was evaluated for dominant lethal mutations in the progeny of male CD rats fed plain feed or diets containing 2,4-DNT concentrations ranging from 0.02 - 0.15% for 10 or 13 weeks. Each male was mated to 2 virgin females, the females sacrificed at mid-pregnancy for analysis of implant viability, and pre- and post-implantation losses. Four separate studies assessed effects associated with graduated dosage ranges, dose selection confounded by infertility due to treatment-related aspermatogenesis. A final 13-week study with male rats (24/group) at dietary exposures of 0, 0.07, 0.10, and 0.15% examined differences in bodyweight, feed consumption, and morphological changes in the genitalia of male rats, while seeking evidence of a reduced fetal viability without treatment-related infertility. In this last study, decreased weight was dose-dependent. There was also a dose-related increase in spermless vaginal plugs and decrease in number of pregnancies (fertility). No significant deviations from control in corpora lutea/dam or implant viability index were noted in the females mated to exposed males. The lack of influence on implant viability index, despite a marked effect on implantation index, conflicts with the presence of dominant lethal mutation. Microscopic examination of treated male reproductive systems revealed marked to severe atrophy or degeneration of seminiferous tubules and insufficient or absent spermatozoa. Upon discontinuation of dietary exposures for 13 weeks, there was no apparent recovery from these effects.[Miles Inc; Mammalian Toxicity of Munitions Compounds Phase III: Effects of Life-Time Exposure, Part 1: 2,4-Dinitrotoluene; 11/01/79; EPA Document # 86940001004; Fiche No. OTS0557413]**UNREVIEWED**
  
• 2,4-Dinitrotoluene (CAS# 121-14-2) was studied for reproductive effects in 50 CD-1 mice when administered by oral gavage for 8 days at 390 mg/kg/day on gestation days 7 through 14. Observations continued through day 3 postpartum. The dose was selected based on the results of a preliminary maximum tolerated dose test on groups of 10 nonpregnant, female CD-1 mice using doses of 310, 525, 1250, 2500 and 3500 mg/kg/day administered by oral gavage for 8 days. A corn oil (vehicle) control was treated similarly to the test group. The test group had 15 deaths including 6 pregnant mice and 4 resorbed pregnancies. The reproductive index (number of females bearing viable litters per number of pregnant females) of the test group was statistically less (p=0.01) than the control group (0.68 vs. 0.91 respectively) as determined by chi-square testing. Other reproductive effects, including maternal weight and maternal weight changes, as well as live and dead pups per litter, litter weights and litter weight changes were not shown to be significantly different as determined by ANOVA or chi-square testing although there seemed to be a trend to lower maternal weight gains during pregnancy.[Bioassay Systems Corporation; Determination of the Reproductive Effects in Mice of Nine Selected Chemicals (1983), EPA Document No. 40-8336210, Fiche No. OTS0506158]**UNREVIEWED**
  
• Dinitrotoluene (CAS# 121-14-2) was evaluated for developmental toxicity. It was administered daily by gavage to 179 (total number) pregnant Fischer 344 rats on gestation days 7-20. Treatment with 0, 14, 35, 37.5, 75, 100 or 150 mg/kg/day of dinitrotoluene resulted in 1/22, 1/13, 0/22, 0/13, 1/23 and 6/13 deaths respectively. Treatment-related clinical signs included rough coat, lethargy and hindlimb weakness in 7/13 rats at 150 mg/kg/day. Dams exhibited significantly increased methemoglobin, increased reticulocyte count, decreased RBC count, decreased hematocrit, increased RBC size, increased platelet count, elevation of organ/body weight ratios and absolute weight gain. Altered fetal relative liver and spleen weight and fetal hematological profile were reportedly not treatment related. Litters from treated dams showed statistically significant but not dose-related differences from controls in litter size, crown-rump length, body weight, reticulocyte count, and appearance of eye opening. Decreased rearing in open field tests was noted at 100 mg/kg/day, and was dose-related for female pups (suggesting sex-specific neuromotor deficit). It was concluded that doses causing maternal and fetal toxicity failed to produce a teratogenic effect, and doses producing facilitation or retardation growth did not exhibit dose-response relationships.[UNION CARBIDE CORP; Teratological and postnatal evaluation of dinitrotoluene in Fischer 344 rats; 7/12/82, EPA 88-920004588, Fiche No. OTS0537569]**UNREVIEWED**
  

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Footnotes

¹ Source: the National Library of Medicine's Hazardous Substance Database, 10/28/2007.