For many years, a class of non-bleach liquid sporicidal disinfectants, also known as cold sterilants, have been used in biological research and pharmaceutical production to control microbial contamination. These are made up of a stabilized mixture of peracetic acid (PAA), hydrogen peroxide and acetic acid. Spor-Klenz®, manufactured by STERIS Life Sciences, is a popular example. Sampling and analysis of PAA is a challenge because it coexists with acetic acid and hydrogen peroxide and PAA’s chemical properties are similar to the two chemicals. Although ACGIH has established a TLV® for PAA, neither NIOSH nor OSHA have a sampling or analytical method for it. Additionally, PAA and acetic acid have STELs which require short-term monitoring.