The ACGIH has recently set a Threshold Limit Value (TLV) Short Term Exposure Limit (STEL) for peracetic acid (PAA) of 0.4 ppm, calculated as a 15 minute time weighted average (TWA). This article discusses the legal significance of a TLV compared to an OSHA Permissible Exposure Limit (PEL).
If OSHA issues a PEL, it is a legal requirement. “Thou shalt not expose thine employees to more than 1 ppm ethylene oxide, calculated as an 8 hour TWA.” Currently, there is no PEL for PAA.
In the US, the ACGIH TLVs are important for two reasons. The first is that an employer using PAA knows there is PAA vapor in the air, may even have measured the concentration, but does not know what concentration is safe. Even if the employer finds a research paper that recommends an exposure level of 0.2 ppm, it does not mean that the employer has to believe that is the safe level. There may be other papers out there with different recommended exposure values.
This blog is intended to give general advice not related to any specific case; consult a lawyer if you have specific legal questions.
The Legal Significance of the New ACGIH TLV for Peracetic Acid