What does EtO stand for and what are the hazards?

• A. Ethylene Oxide; used for sterilization; mutagenic and carcinogenic
• B. Ethyl Trioxide; used for disinfection; harmless
• C. Ethylene Oxygen; used for ventilation; inert
• D. Ethanol; used for cleaning; flammable

Answer: (A)

EtO stands for Ethylene Oxide, a low‑temperature gas used to sterilize heat‑sensitive medical devices that can’t be steam sterilized. The hazards come from its toxic, mutagenic, and carcinogenic nature, meaning exposure can cause genetic damage and increase cancer risk. It is also highly flammable and can form explosive mixtures in air, so sterilization systems require tight sealing, strong ventilation, and continuous gas monitoring, along with aeration to remove residual EtO before handling. Proper training, procedures, and personal protective equipment are essential to keep exposure within safe limits. The other options misname the chemical or its use and hazards—Ethyl Trioxide and Ethylene Oxygen aren’t correct terms for this context, and Ethanol is a different chemical used mainly as a cleaner and is not the sterilant described here.