Dimethylformamide, occupational exposure

Redlich CA, Beckett WS, Sparer J, et al Liver disease associated with occupational exposure to the solvent dimethylformamide. Ann Int Med 108 680-686, 1988... 

According to the 1981-83 United States National Occupational Exposure Survey (NOES, 1997), as many as 125 000 workers in the United States were potentially exposed to dimethylformamide (see General Remarks). Occupational exposures to dimethylformamide may occur in the production of the chemical, other organic chemicals, resins, fibres, coatings, inks and adhesives. Exposure also may occur during use of these coatings, inks, adhesives, in the synthetic leather industry, in the tanning industry and in the repair of aircraft (Ducatman et al., 1986 lARC, 1989). 

The American Conference of Governmental Industrial Hygienists (ACGIH) (1997) has recommended 30 mg/m as the 8-h time-weighted average threshold limit value, with a skin notation, for occupational exposures to dimethylformamide in workplace air. Values of 10-60 mg/m3 have been used as standards or guidelines in other countries (International Labour Office, 1991). 

Seiji et al. (1992) studied the effects of occupational exposure to dimethylformamide on sister chromatid exchange rates in peripheral lymphocytes from 22 dimethylformamide-exposed women (aged 22-52 years) in comparison with 22 sex-, age- and residence-matched controls. All subjects were non-smokers and non-drinkers of alcohol as confirmed by medical interview. The 22 pairs were divided into three subgroups according to the intensity of their exposure to dimethylformamide high exposme (8 pairs with mean exposme of... 

Redlieh, C.A., West, A.B., Fleming, L., True, L.D., Cullen, M.R. Riely, C.A. (1990) Clinical and pathological characteristics of hepatotoxicity associated with occupational exposure to dimethylformamide. Gastroenterology, 99, 748-757... 

Occupational exposure to formamide may occur through inhalation and dermal contact with this compound at workplaces where formamide is produced or used. Formamide, a physiological product of N,N-dimethylformamide, was detected in the urine of synthetic leather factory workers. Formamide may be inhaled, swallowed, or absorbed through the skin. The chemical is moderately irritating to the skin and can produce from mild to severe irritation to the eye. In its usual application, inhalation is the most common route of exposure although dermal contact is always possible. 

Walrath J, Fayerweather WE, Gilby PG, et al A case-control study of cancer among Du Pont employees with potential for exposure to dimethylformamide. J Occup Med 31 432M38, 1989... 

Chromosomal aberrations in peripheral lymphocytes were also reported in a study of about 40 workers who had been occupationally exposed to trace quantities of 2-butanone (methyl ethyl ketone), butyl acetate, toluene, cyclohexanone and xylene in addition to dimethylfonnamide. Blood samples were taken at two Ibur-nionth intervals, when exposure was to an average of 180 and 150 mg/nr dimethylformamide, respectively. The frequencies of chromosomal aberrations were 3.82% and 2.74% at these two sampling times. Subsequent sampling at tliree six-month intervals, when average dimethylformamide exposures were to 50, 40 and 35 mg/m- , gave lower aberration frequencies of 1.59%, 1.58% and 1.49%. Aberration frequencies in two control groups were 1.61% and 1.10% (Koudela Spazier, 1981). 

The Working Group was also aware of inhalation studies with dimethylformamide conducted for the United States National Institute of Occupational Health. These involved exposure to 400 ppm [1200 mg/m ] for 7 h in a rat bone-marrow cell cytogenetic study, for 7 h per day for five days in a rat bone-marrow cell cytogenetic study, a male rat dominant lethal assay and a mouse sperm morphology assay and for 2.25 h in a Drosophila melanogaster sex-linked recessive lethal assay. All results were negative. 

Ikeda, M. (1992) Occupational dimethylformamide exposure. 3. Health effects of dimethyl-... 

Kawai, T., Yasugi, T., Mizunuma, K., Watanabe, T.. Cai, S.-X., Huang, M.-Y, Xi, L.-Q., Qu, J.-B., Yao, B.-Z. Ikeda, M. (1992) Occupational dimethyl formamide exposure. 2. Mono-methylformamide excretion in urine after occupational dimethylformamide exposure. Int. Arch, occup. environ. Health, 63, 455-460... 

Dimethylacetamide is used as a solvent in the manufacture of plastics and as a paint remover. Occupational poisoning and hepatotoxicity to extreme eoneentrations of dimethylacetamide (DMA) are reported in the medical literature. Deereases in hepatie clearance measures and alterations in hepatic transaminases with hepatomegaly have been reported at lower doses.Like dimethylformamide, DMA is readily absorbed through the skin. Chronic exposures in workers exposed to low air concentrations of DMA of less than 3 ppm and with biological monitoring assessments to measure dosages by dermal absorption demonstrated little evidence of hepatotoxicity by clinical chemistries. "... 

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