Chemical of the Week – Peracetic Acid

Peracetic acid is what happens when you take acetic acid (vinegar’s active ingredient) and add an extra oxygen atom, transforming a kitchen staple into a powerful oxidizer that’s equal parts useful and ornery. This pungent, colorless liquid with a sharp vinegar-like odor is widely used as a disinfectant and sanitizer in food processing, healthcare, and water treatment, but don’t let its cleaning credentials fool you: it’s a strong corrosive that attacks skin, eyes, and respiratory tissue on contact, it’s a potent oxidizer that can ignite combustibles or explode when concentrated, and it has an annoying habit of decomposing into oxygen and acetic acid when it gets warm, building pressure in containers until they rupture or vent aggressively. The real headache is that peracetic acid is typically sold in equilibrium mixtures with hydrogen peroxide, acetic acid, and water, meaning spills release multiple hazards simultaneously, and the solution’s strength can vary wildly from dilute sanitizer (safe-ish) to concentrated industrial grade (definitely not safe). Whether you’re responding to a food plant incident, wastewater treatment facility leak, or transportation spill, verify the concentration immediately, treat it as both a corrosive and an oxidizer, ensure excellent ventilation to handle the vapors, and remember that containers under pressure from decomposition can turn into projectiles or geysers without warning. Respect peracetic acid as the high-maintenance oxidizer it is, and never assume that “it’s just a sanitizer” means you can skip proper PPE or atmospheric monitoring.

Have fun and let us know how you did in researching the hazards.