Evaluation of the toxicity data for peracetic acid in deriving occupational exposure limits: A minireview

• A mini-review of the toxicity data for peracetic acid (PAA) was conducted in the context of deriving health-based occupational exposure limits (OEL).
• The available toxicity data for PAA frequently suffer from deficiencies in reporting, information gaps and unconventional testing methodology
• In spite of these limitations, sensory irritation is identified as the most sensitive health endpoint and serves as the point-of-departure upon which health-based OELs are derived.
• Time-weighted average (TWA) OELs are derived and range from 0.36 to 0.51 mg/m3 (0.1–0.2 ppm). Short-term exposure limit (STEL) OELs also are derived and range from 1.2 to 1.7 mg/m3 (0.4–0.5 ppm).
• A joint TWA/STEL approach is recommended to effectively mitigate PAA workplace inhalation hazards with selection of specific OELs within the proposed ranges being a risk management decision.

Peracetic acid (PAA) is a peroxide-based chemistry that is highly reactive and can produce strong local effects upon direct contact with the eyes, skin and respiratory tract. Given its increasing prominence in industry, attention has focused on health hazards and associated risks for PAA in the workplace. Occupational exposure limits (OEL) are one means to mitigate risks associated with chemical hazards in the workplace. A mini-review of the toxicity data for PAA was conducted in order to determine if the data were sufficient to derive health-based OELs. The available data for PAA frequently come from unpublished studies that lack sufficient study details, suffer from gaps in available information and often follow unconventional testing methodology. Despite these limitations, animal and human data suggest sensory irritation as the most sensitive endpoint associated with inhalation of PAA. Rodent RD50 data (the concentration estimated to cause a 50% depression in respiratory rate) were selected as the critical studies in deriving OELs. Based on these data, a range of 0.36–0.51 mg/m3 (0.1–0.2 ppm) was calculated for a time-weighted average (TWA), and 1.2–1.7 mg/m3 (0.4–0.5 ppm) as a range for a short-term exposure limit (STEL). These ranges compare favorably to other published OELs for PAA. Considering the applicable health hazards for this chemistry, a joint TWA/STEL OEL approach for PAA is deemed the most appropriate in assessing workplace exposures to PAA, and the selection of specific values within these proposed ranges represents a risk management decision.