| Toxizitätsübersicht | IDENTIFICATION AND USE: N,N-Dimethylaniline is a pale-yellow, oily liquid with amine-like odor that solidifies below 36 degrees F. It is used as a solventan intermediate in the manufacture of vanilin, methyl violet, other dyes, and Michler's ketoneas a reagentas a catalytic hardener in certain fiberglass resinsand as an acid scavenger or acceptor in the manufacture of semisynthetic penicillins and cephalosporins. HUMAN EXPOSURE AND TOXICITY: N,N-Dimethylaniline has been reported to be quantitatively less toxic than aniline but produces a very similar effect notably, methemoglobinemia. The human lethal oral dose is 50 mg/kg. Short-term exposure: contact may irritate or burn the eyes, and may irritate the nose and throat. It can be absorbed through the skin, thereby increasing exposure. Swallowing the liquid may cause aspiration into the lungs with the risk of chemical pneumonia. The chemical may affect the blood, resulting in formation of methemoglobin. Symptoms of anoxia, cyanosis, weakness, dizziness, ataxia. Symptoms may be delayed. Long term exposure: repeated or prolonged contact with skin may cause dermatitis. While this chemical has not been identified as a reproductive hazard, there are some evidence that women working with aniline, a related compound, have a higher incidence of reproductive cycle disorders and abortions. There are case reports of two workers who showed symptoms very similar to aniline poisoning. One of the workers, who was exposed for only a few minutes to hot vapors from a vat containing dimethylaniline and phenol, collapsed immediately, was unconscious for 8 hours, and complained of visual disturbances, noise in the ears, and intense abdominal pain. The other worker was less severely poisoned after 7 hours of baling dimethylaniline from one container to another. The compound was not irritating when approximately 0.1 g of petrolatum containing 0.6% N,N-Dimethylaniline was applied to the backs of human subjects for 24 hours. There is inadequate evidence in humans for the carcinogenicity of N,N-dimethylaniline. ANIMAL STUDIES: When mice were injected with 65 mg/kg N,N-Dimethylaniline for 3 days, 1.8 % metHb and 2.0 % sulfhemoblobin were found in the blood 48 hours after the last dose. Rats inhaling dimethylaniline at 0.3 mg/cu m for 24 hours/day for 100 days showed significant changes in the central nervous system, blood, and liver, including changes in the correlation of muscle antagonist chronaxy, a reduced number of erythrocytes and hemoglobin, increased methemoglobin level, reticulocytosis, leukopenia, hypoproteinemia, a reduced sulfhydryl group content in the serum, and accumulation of pyruvic acid in the liver and serum. Dimethylaniline increased the coproporphyrin urinary excretion and reduced the adrenal ascorbic acid level. Dimethylaniline at 0.005 mg/cu m did not change the above parameters. In other experiments, splenomegaly was observed in rats and mice given a daily dose of up to 500 mg of N,N-dimethylaniline/kg body weight 5 days/wk for 13 wk. Microscopic examination revealed the presence of hemosiderosis and hematopoiesis in the spleens, livers, and kidneys of treated rats and mice. Bone marrow hyperplasia was noted in treated rats but not mice. N,N-Dimethylaniline was evaluated for developmental toxicity (litter size as well as the birth weight, neonatal growth, and survival of pups) in a short-term in vivo animal bioassay. Fifty pregnant mice were given 365 mg/kg/day N,N-dimethylaniline in corn oil by gavage on days 6-13 of gestation. N,N-Dimethylaniline had no toxic effect in the dams or in their offspring for the parameters assayed. N,N-dimethylaniline was found to be negative when tested for mutagenicity in the Salmonella/microsome preincubation assay in 5 Salmonella typhimurium strains (TA1535, TA1537, TA97, TA98, and TA100). The highest ineffective dose tested in any Salmonella typhimurium strain was 333.000 ug/plate. There is limited evidence in experimental animals for the carcinogenicity of N,N-dimethylaniline. Urinary metabolites of N,N-dimethylaniline produced in dogs were 4-aminophenol, 4-(methylamino)phenol, 4-(dimethylamino)phenol, 2-aminophenol, and N-methylaniline. |
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