FAQ Group: HEPA Filters

In some BSC work, radioisotopes solutions are used. These solutions could give off radioactive vapors which would pose a Beta and even Gamma radiation hazard. Since a HEPA filter will not stop vapors, it is expected that the radiation will leave the BSC and exit the building. Prior to accessing and changing a HEPA filter, it is good practice to have a health physicist assess and document that the BSC is free of radiation hazards or to supervise any safety measures required by a radiation hazard if it exists. The HEPA filter itself would be decontaminated as biological and/or chemical waste (see the other sections), prior to removal and be disposed of a non-hazardous waste unless otherwise regulated. If the HEPA filters did contain radioactive waste, the health physicist would advise on proper disposal procedures.

HEPA filters used in BSCs for chemo (antineoplastic) drug preparation pose a chemical hazard as opposed to a biological hazard. Typically, BSCs are used for either biohazard or chemo drug work therefore mixing of these two types of hazards are rare. Chemo drugs can pose a variety of acute and chronic occupational exposure hazards. The current guideline document is published by OSHA: in Chapter 21 of their technical manual. When a HEPA filter is changed in a BSC used for chemo drugs, the old filter is classified as hazardous drug (HD) waste. It should be bagged in plastic, labeled, and disposed of as solid hazardous drug waste. Disposal of HD waste can be regulated by the EPA, state, and local toxic waste laws depending on the drugs used. It is important that the facility have in place a hazardous drug safety and health plan which would document how HD waste should be disposed.

HEPA filters in BSCs used for biohazard work are viewed as contaminated with whatever biological agents used in the BSC. The OSHA Bloodborne Pathogen Standard states equipment which may be contaminated with blood or other potentially infectious materials….shall be decontaminated as necessary. This procedure is detailed in NSF International Standard 49 Informative Annex 2. Most HEPA filters that have been decontaminated are viewed as non-hazardous and are disposed of as non-regulated waste. Some biological agents are resistant to gaseous decontamination and may need special handling. In some states or localities there may be regulations that prohibit non-regulated disposal of any perceived medical waste. So even if a HEPA filter is decontaminated, the HEPA may still be incinerated or packaged as medical waste.

High Efficiency Particulate Air (HEPA) filters are used in biological safety cabinets (BSCs), laminar air flow clean workstations, and other air handling equipment to provide clean work environments. In the case of BSCs they also provide worker and environmental protection by removing contaminants from the air. When a HEPA filter is changed, the proper disposal of the used HEPA is always a concern. HEPA filters from laminar air flow workstations and other product protection applications may only filter room air therefore filters may contain only the normal particulates found in air. These filters are typically not viewed as being contaminated and can be disposed of as non-regulated waste.