GLYCERIN MIST

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: 56-81-5; Chemical Formula: CH₂OHCHOHCH₂OH

OSHA formerly had no specific limit for glycerin mist, although this substance was previously regulated at 15 mg/m³ under the generic total particulate limit. The ACGIH has a TLV-TWA of 10 mg/m³ (total particulate) for glycerin. OSHA proposed a total particulate PEL of 10 mg/m³, and the final rule promulgates this limit and retains the 5-mg/m³ limit for the respirable fraction. Glycerin is an oily, hygroscopic liquid with a warm, sweet taste.

Glycerin was long considered to be nontoxic; however, there are indications that the mist may be injurious to the kidneys at very high exposure levels (Campanacci 1965/Ex. 1-1047). NIOSH (Ex. 8-47) states that, at high concentrations, exposure may cause hemolysis, hemoglobinuria, and renal failure. Ackermann, Bassler, and Wagner (1975, as cited in ACGIH 1986/Ex. 1-3, p. 286) have reported that glycerin mist is easily metabolized and excreted. In the adult human of average weight, 2 grams of glycerol can be metabolized and excreted in an 8-hour workday. At this metabolic and elimination rate, the ACGIH believes that no ill effects are likely to occur as a result of exposure at or below 10 mg/m³ as an 8-hour TWA (ACGIH 1986/Ex. 1-3, p. 286).

NIOSH, the only commenter on this substance, does not agree that the final rule’s limit of 10 mg/m³ is appropriate for glycerin mist because a recent study by Wiebe and Barr (1984, as cited in Ex. 8-47) found reproductive effects in rats injected intratesticularly with glycerin mist (Ex. 8-47).

OSHA is establishing an 8-hour TWA limit of 10 mg/m³ (total particulate) and retaining the 5-mg/m³ (respirable particulate) limit for glycerin mist. The Agency concludes that these limits will provide protection against the significant risks of glycerin exposure, which include kidney damage and, perhaps, testicular effects. OSHA finds that these health effects constitute material health impairments, and the Agency intends to monitor the literature on glycerin in the future.