Ethylene oxide is one of the largest volume chemicals produced in the world primarily as a chemical intermediate, especially for the manufacture of antifreeze, surfactants, thickeners and detergents, solvents, plastics, and organic chemicals. The EtO molecule contains a very strained three-membered ring which makes it very reactive and so very useful to the chemical industry. This high reactivity also make EtO a very effective biocide against all forms of microorganisms, including bacterial spores and protozoal cysts. EtO one of the most efficient low temperature sterilization methods and it is used for about half of all the medical devices produced in the world today. Every facility that is using Ethylene Oxide, should employ a ChemDAQ gas monitoring system to ensure the safety and health of their workers. 

Not surprisingly for a sterilent gas, EtO is potentially hazardous to anyone exposed to it. In the short term EtO is an irritant, but more concerning is the fact that EtO is also a known carcinogen (IARC, NTP, EPA). The occupational exposure limits from OSHA (1 ppm PEL) reflect this hazard any location where EtO is used, should have continuous monitoring. The high reactivity of EtO also results in ethylene oxide being explosive, with a lower explosive limit of 3 % v/v with an upper explosive limit of 100% v/v. In areas where there is the risk of a flammable EtO gas mixture occurring, then only intrinsically safe monitors and other technology approved from that environment should be used. For example, ChemDAQ offers sensors for EtO from 0 to 100 % LEL (3% v/v), ppm levels of EtO and oxygen that are intrinsically safe.

Microbial Activity: Ethylene oxide has been shown to be effective as a sterilant against all forms of microorganisms, including bacterial spores and protozoal cysts. EtO is a direct alkylating agent that does not require metabolic activation, and its microbiologic inactivation properties are the result of alkylation cellular constituents of organisms, such as nucleic acid and functional proteins, including enzymes, which leads to consequent denaturation.