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Yet Another Chemical of Emerging Concern – EtO

Yet Another Chemical of Emerging Concern - EtO

Not all chemicals of emerging concern are dissolved in water. While per- and polyfluoroalkyl substances are dramatically called “forever chemicals” by the media and make the headlines, numerous other chemicals are gaining notoriety due to their distribution, and public exposure. One such compound is ethylene oxide (EtO), which is rapidly becoming an issue because of a different route of exposure – inhalation, rather than ingestion. 

EtO is a flammable, colorless gas used to make other chemicals in making a range of products, including antifreeze, textiles, plastics, detergents, and adhesives. But its most controversial use is as a sterilizer for equipment and plastic devices that cannot be sterilized by steam, such as medical equipment.

US EPA recently updated its risk value for EtO and is working with industry and state, local and tribal air agencies to address this chemical. The Clean Air Act requires US EPA to regulate emissions of hazardous air pollutants from industrial facilities and control these emissions by developing and implementing standards and guidelines. EtO is a hazardous air pollutant that is emitted from several types of industrial facilities that are regulated by US EPA, including:

  • Commercial Sterilizers
  • Hospital Ethylene Oxide Sterilizers
  • Miscellaneous Organic Chemical Manufacturing
  • Polyether Polyols Production
  • Synthetic Organic Chemical Manufacturing Industry

As stated in an article published in Inside EPA, “Environmentalists are urging EPA to accelerate its ongoing Clean Air Act call for information on ethylene oxide (EtO) usage at sterilization facilities, saying the agency is not acting quickly enough in pursuing rules to restrict emissions of the chemical that is blamed for causing cancer.” But US EPA already issued one rule tightening EtO emissions limits in the miscellaneous organic chemical manufacturing market. US EPA has not tightened limits or obligations for medical sterilization plants. It is these plants that are often creating local headlines.

US EPA is not the only federal agency that has an interest in EtO. The chemical’s characteristics and use have also drawn the attention of The Occupation Health & Safety Administration (OSHA), which has published guidance and information related to EtO. Unfortunately, EtO, which is both flammable and highly reactive, possesses several physical and health hazards that merit special attention. EtO is used extensively by hospitals and other industries as a sterilizing agent. EtO is a colorless, odorless gas, which you cannot smell until it reaches levels that can cause serious harm to human health (NIOSH, 1989). Human and animal studies consistently show that EtO can be hazardous to human health. Short-term exposures to EtO can cause respiratory irritation and lung injury, shortness of breath, headache, nausea, vomiting, and diarrhea. Long-term exposure over many years may cause cancer, reproductive effects, genetic changes, and damage to the nervous system (Lamontagne et al., 1990).

Exposures to EtO are addressed in specific OSHA standards for general industry, maritime, and construction. OSHA’s “action level” is the 8-hour exposure level that triggers certain actions under OSHA’s EtO standard. If an employee’s 8-hour sample result is equal to or greater than the action level, the employer must start certain required activities such as exposure monitoring and medical surveillance. The action level for EtO is 0.5 ppm (which equals 0.9 mg/m3).

Measuring EtO in the air requires a careful analytical-chemistry solution that industry, regulators, and impacted communities are widely ignoring. As EtO continues to hit the headlines, our clients need to be using high-quality data so they can be certain that the reported concentrations in the workplace and at the fenceline comply with regulations – data that can be reliably used for reporting, making decisions, and defending, the use of this important sterilizing chemical. For more information on how Environmental Standards can help, contact David Blye at our Valley Forge, Pennsylvania office. 

Additional References

Lamontagne, AD, Oakes, JM, and Lopez, RN. 2004. Long-Term Ethylene Oxide Exposure Trends in U.S. Hospitals: Relationship with OSHA Regulatory and Enforcement Actions. American Journal of Public Health. 94: (9), 1614-1619.

NIOSH. 1989. Technical Report: Control Technology for Ethylene Oxide Sterilization in Hospitals. Report No. 89-120. National Institute for Occupational Safety and Health. 89-120.pdf (179 pages, 4,133K).

Gerry Kirkpatrick, P.G.

Managing Partner