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Technology Transfer Network - OAR Policy and Guidance





  • On March 31, 2006, the Environmental Protection Agency (EPA) made a final decision to retain without modification its Clean Air Act rule that limits emissions of toxic air pollutants from existing ethylene oxide sterilization facilities. See more information below to obtain a copy of the final amendments.
  • EPA analyzed emissions from these facilities after implementation of the 1994 air toxics rule and determined that the risks to human health and to the environments are low. Therefore, EPA need not require further emissions reductions.
  • Commercial sterilization facilities use ethylene oxide to sterilize heat- and moisture-sensitive products and as a fumigant to control microorganisms or insects. There are approximately 100 of these facilities in the U.S. covered by the ethylene oxide emissions standards.
  • EPA issued a national rule to limit emissions of toxic air pollutants from these facilities in 1994. That rule is one of 96 rules called maximum achievable control technology (MACT) standards that require 174 industry sectors to eliminate 1.7 million tons per year of 187 toxic air pollutants. Congress listed these toxic air pollutants in the Clean Air Act.
  • The 1994 MACT standards for ethylene oxide sterilization facilities reduce emissions of toxic pollutants by approximately 1,000 tons each year.
  • The Clean Air Act requires EPA to assess the risk remaining after the application of the 1994 MACT. These are called residual risk assessments.
  • The Clean Air Act also requires EPA to review and revise, as necessary, the 1994 standards by taking into account developments in practices, processes, and control technologies.
  • EPA considered the public comments received on the proposal and we are finalizing the decision as proposed.
  • EPA is making a final decision that no further action is necessary to revise the standards, because:
    - The risk assessment found that after application of the standards, the chronic cancer, noncancer, and acute risks to humans, as well as ecological effects, from these facilities are low enough that further controls are not warranted.
    - In our technology assessment, we did not identify any advancements in practices, processes, or control technology.
  • The final action responds to public comments on the residual risk assessment and technology review and announces EPA’s final decision to take no further action to revise the standards.

  • The Clean Air Act requires EPA to regulate air toxics from large industrial facilities in two phases.
  • The first phase is “technology-based,” where EPA develops standards for controlling the emissions of air toxics from sources in an industry group (or “source category”). These maximum achievable control technology (MACT) standards are based on emissions levels that are already being achieved by the better-controlled and lower-emitting sources in an industry.
  • Within 8 years of setting the MACT standards, EPA is required to assess the remaining health risks from each source category to determine whether the MACT standards appropriately protect public health. Applying this “risk-based” approach called residual risk, EPA must determine whether more health-protective standards are necessary.
  • Also, every 8 years after setting the MACT standards, the Clean Air Act requires that EPA review and revise the standards, if necessary, to account for improvements in air pollution controls and/or prevention.

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