Aeration process means any time when ethylene oxide is removed from the aeration unit through the aeration unit vent or from the combination sterilization unit through the sterilization unit vent, while aeration or off-gassing is occurring.

Aeration unit means any vessel that is used to facilitate off-gassing of ethylene oxide.

Air pollution control device means a catalytic oxidizer, acid-water scrubber, or any other air pollution control equipment that reduces the quantity of ethylene oxide in the effluent gas stream from sterilization and aeration processes.

Combination sterilization unit means any enclosed vessel in which both the sterilization process and the aeration process occur within the same vessel, i.e., the vessel is filled with ethylene oxide gas or an ethylene oxide/inert gas mixture for the purpose of sterilizing and is followed by off-gassing of ethylene oxide.

Common aeration time means that items require the same length of time to off-gas ethylene oxide.

Full load means the maximum number of items that does not impede proper air removal, humidification of the load, or sterilant penetration and evacuation in the sterilization unit.

Hospital means a facility that provides medical care and treatment for patients who are acutely ill or chronically ill on an inpatient basis under supervision of licensed physicians and under nursing care offered 24 hours per day. Hospitals include diagnostic and major surgery facilities but exclude doctor's offices, clinics, or other facilities whose primary purpose is to provide medical services to humans or animals on an outpatient basis.

Hospital central services staff means a healthcare professional, including manager and technician, who is either directly involved in or responsible for sterile processing at a hospital.

Medically necessary means circumstances that a hospital central services staff, a hospital administrator, or a physician concludes, based on generally accepted medical practices, necessitate sterilizing without a full load in order to protect human health.

State or local regulation means a regulation at the State or local level that requires a hospital to reduce the quantity of ethylene oxide emissions from ethylene oxide sterilization units.

Sterilization facility means the group of ethylene oxide sterilization units at a hospital using ethylene oxide gas or an ethylene oxide/inert gas mixture for the purpose of sterilizing.

Sterilization process means any time when ethylene oxide is removed from the sterilization unit or combination sterilization unit through the sterilization unit vent.

Sterilization unit means any enclosed vessel that is filled with ethylene oxide gas or an ethylene oxide/inert gas mixture for the purpose of sterilizing. As used in this subpart, the term includes combination sterilization units.