OSHA comments from the January 19, 1989 Final Rule on Air Contaminants Project extracted from 54FR2332 et. seq. This rule was remanded by the U.S. Circuit Court of Appeals and the limits are not currently in force.

CAS: 118-96-7; Chemical Formula: C7H5N3O6

OSHA’s former PEL for 2,4,6-trinitrotoluene (TNT) was 1.5 mg/m3 as an 8-hour TWA, with a skin notation. The ACGIH has set a TLV-TWA of 0.5 mg/m3, also with a skin notation, for this chemical. The proposed PEL was 0.5 mg/m3 as an 8-hour TWA, and the final rule establishes this limit; the skin notation is retained. NIOSH (Ex. 8-47, Table N1) agrees that this limit is appropriate. TNT occurs as yellow, needle-like crystals and is used as an explosive.

The ACGIH’s limit was selected on the basis of health surveys conducted among occupationally exposed workers. Fairhall (1957e, as cited in ACGIH 1986/Ex. 1-3, p. 610) describes dermatitis, cyanosis, gastritis, acute yellow atrophy of the liver, and aplastic anemia as possible effects of exposure to TNT. According to Sollman (1957/Ex. 1-991), blood destruction, leucocytosis or leucopenia, and varying degrees of central nervous system change (probably resulting from anoxia, peripheral neuritis and muscular pains, cardiac muscular and menstrual irregularities, and urinary and renal irritation) can also occur as a consequence of TNT exposure. TNT has irritant properties and may cause sneezing, sore throat, or skin irritation (von Oettingen 1941/Ex. 1-874).

A study by Goodwin (1972/Ex. 1-556) revealed 36 cases of liver damage in a munitions plant where workers were exposed to a mean air level of 2.38 mg/m3 TNT over a period of 20 years. Another study (Morton, Ranadive, and Hathaway 1976/Ex. 1-566) found elevated levels of liver enzymes in 43 TNT shell-packers and loaders who worked where TNT exposures ranged from 0.3 to 0.8 mg/m3 over a period of five months. In 1975, Djerassi and Vitany (Ex. 1-550) published a paper describing hemolytic episodes in three TNT workers with glucose-6-phosphate dehydrogenase deficiency; although these workers were from Iraq, where G-6-PDase deficiency has a high (25 percent) frequency of occurrence, the study is also of concern for other workers having a high frequency of G-6-PDase deficiency. NIOSH was the only commenter to the record on TNT.

In the final rule, OSHA is establishing an 8-hour TWA of 0.5 mg/m3 for 2,4,6-trinitrotoluene; the skin notation is retained. The Agency concludes that this limit is necessary to protect workers against the significant risk of liver damage and hemolytic effects potentially associated with exposure to TNT. OSHA has determined that this limit will substantially reduce these significant risks and that liver damage and hemolysis constitute material health impairments.