n-VALERALDEHYDE

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: 110-62-3; Chemical Formula: CH₃(CH₂)₃CHO

OSHA formerly had no limit for n-valeraldehyde. The ACGIH limit is 50 ppm as an 8-hour TWA for n-valeraldehyde, which is a colorless liquid. The proposed PEL was 50 ppm as an 8-hour TWA, and NIOSH (Ex. 8-47, Table N1) concurs that this limit, which is established by the final rule, is appropriate.

n-Valeraldehyde’s toxic effects include both skin and eye irritation. Animal studies showed n-valeraldehyde to be severely irritating when applied to guinea pig skin and to rabbits’ eyes (Fassett, as cited in ACGIH 1986/Ex. 1-3, p. 619). The dermal LD(50) for guinea pigs exceeds 20 ml/kg (Fassett, as cited in ACGIH 1986/Ex. 1-3, p. 619).

A series of studies of the relative acute inhalation toxicity of 13 aliphatic saturated and unsaturated aldehydes in mice, guinea pigs, and rabbits showed that valeraldehyde was relatively nontoxic systemically (Salem and Cullumbine 1960/Ex. 1-360). Only NIOSH commented on this substance.

In the final rule, OSHA is establishing a 50-ppm 8-hour TWA limit for this previously unregulated chemical. The Agency concludes that this limit will protect workers from the significant risk of severe eye and skin irritation associated with exposure to this substance at levels above the new PEL.