HEPA filters must be:

• A. Removed when dirty and discarded as contaminated waste
• B. Cleaned and reused
• C. Escalated to a higher level of filtration
• D. Replaced on a fixed schedule regardless of condition

Answer: (A)

HEPA filters in asbestos work are the last line of defense against released fibers. Once a filter becomes loaded with asbestos, cleaning it can shake fibers loose and reintroduce them into the air, so it must be removed and discarded as contaminated waste. Reusing or cleaning the same filter is not acceptable, because it would no longer reliably contain fibers. Replacing on a fixed schedule or increasing filtration level without regard to actual contamination doesn’t guarantee safety, whereas removing a dirty filter and replacing it with a clean one directly maintains the containment barrier and protects workers.