NIOSH Proposes new IDLH for Peracetic Acid

The National Institute of Occupational Safety and Health (NIOSH) has approved an Immediately Dangerous to Life and Health (IDLH) limit for peracetic acid (PAA) at 0.6 ppm.

OSHA defines an IDLH as “An atmospheric concentration of any toxic, generic corrosive or asphyxiant substance that poses an immediate threat to life or would cause irreversible or delayed adverse health effects or would interfere with an individual’s ability to escape from a dangerous atmosphere.” [29 CFR* 1910.120]. NIOSH publishes a list of chemicals and their IDLH values on their website

NIOSH initially proposed an IDLH of 0.64 ppm for PAA and posted the proposal in the Federal Register for external review in March 2015, hospital along with 13 other compounds. There were no comments for PAA or any or any of the other chemicals for that matter, which is surprising considering how widespread PAA is used, from healthcare, food processing, and water treatment. It’s also surprising given how low the IDLH is relative the ACGIH‘s STEL TLV or 0.4 ppm (15 min time weighted average). It appears that no-one saw the post, probably because the Federal Register did not list PAA on the contents page and so it was not picked up by the various search engines and services.

At the time of writing this blog, NIOSH has approved the new IDLH for PAA at 0.6 ppm and is expecting to publish the value this summer.

Concerns are being heard from various industries and organizations. The Aseptic and Antimicrobial Processing and Packaging Association (AAPPA), an industry consortium focusing on the safe use of PAA, hydrogen peroxide and other chemicals used for aseptic packaging and antimicrobial processing, has had many members express concern about how the new IDLH will impact their businesses. The organization plans to continue discussions and form a plan of action concerning the regulation and best practices.