Systematic review of the scientific evidence on ethylene oxide as a human carcinogen

Chem Biol Interact. 2022 Sep 1:364:110031. doi: 10.1016/j.cbi.2022.110031. Epub 2022 Jun 30.


Ethylene oxide is a highly reactive chemical primarily used as an intermediate in chemical production and as a sterilant of medical equipment and food products; it also is produced endogenously as a result of physiological processes. We conducted a systematic review of the potential carcinogenicity of inhaled ethylene oxide in humans using methods that adhere to PRIMSA guidelines and that incorporate aspects from the Institute of Medicine (IOM) (now the National Academy of Medicine) as well as several US Environmental Protection Agency (EPA) frameworks for systematic reviews. After a comprehensive literature search and selection process, study quality was evaluated following a method adapted from the EPA Toxic Substances Control Act (TSCA) framework. The literature screening and selection process identified 24 primary studies in animals or humans and more than 50 mechanistic studies. Integrating epidemiological, animal, and mechanistic literature on ethylene oxide and cancer according to the IOM framework yielded classifications of suggestive evidence of no association between ethylene oxide and stomach cancer, breast cancer and lymphohematopoietic malignancies at human relevant exposures. However, we acknowledge that there is additional uncertainty in the classification for lymphohematopoietic malignancies owing to a paucity of evidence for specific types of these tumors, each of which is a distinct disease entity of possibly unique etiology.

Keywords: Carcinogenicity; Ethylene oxide; Systematic review.

Publication types

  • Review
  • Systematic Review

MeSH terms

  • Animals
  • Breast Neoplasms*
  • Carcinogens* / toxicity
  • Ethylene Oxide / toxicity
  • Female
  • Humans
  • United States
  • United States Environmental Protection Agency


  • Carcinogens
  • Ethylene Oxide