Abatement Work Practices, Engineering Controls, and Worker Protection
Containment and engineering controls
Abatement relies on containment plus suppression. Regulated areas are bounded by critical barriers (usually two layers of 6-mil poly over openings), with remaining openings sealed. Negative pressure is maintained with HEPA-filtered air movers sized for roughly 4–6 air changes per hour and verified by manometer at about −0.01 inches of water column relative to outside. Decontamination units provide a clean room, shower, and equipment room - three stages on large projects - and work and waste move outward, never back into clean space. HVAC systems are shut down, isolated, and locked out. Wet methods are used during removal and cleanup; dry sweeping and compressed air are prohibited; only HEPA vacuums are used.
Removal technique
Remove material in the largest practical sections, keep it wet, and avoid breaking or dropping it. Use glove bags for short vertical pipe runs, mini-enclosures for small fittings, and wrap-and-cut for isolated pipe sections. Bag waste as it is generated and seal it in 6-mil poly.
Worker protection
Respirator selection follows 1926.1101 Table 1: half-mask HEPA air-purifying respirator up to 10× PEL (max 1.0 f/cc); full-facepiece APR up to 50× (5.0 f/cc); full-facepiece tight-fitting PAPR up to 100× (10 f/cc); supplied-air above that. Add disposable coveralls, boot covers, hoods, and gloves. No eating, drinking, smoking, or chewing in the work area; wash and shower before leaving; annual fit testing and medical evaluation under 1910.134.
Rule of thumb
Match control to job: glove bag for a few fittings, mini-enclosure for a small valve cluster, full negative-pressure enclosure for anything that cannot stay intact. If the manometer will not hold about −0.01 in. w.c., stop removal.