State-of-the-Art Work Practices and Abatement Methods
Methods a supervisor must recognize
Abatement approaches include removal, enclosure, encapsulation, and repair. Removal is preferred when material is damaged or will be disturbed; enclosure builds a sealed barrier around it; encapsulation coats it to bind fibers.
Containment and engineering controls: critical barriers, negative air pressure machines with HEPA filtration, decontamination units, and plastic sheeting on floors and walls. Wet methods suppress fiber release. HEPA vacuums clean surfaces. Glove bags allow small removals without a full containment.
Work sequencing: isolate the area, post signs, establish regulated areas, shut down HVAC, build containment, establish negative pressure, remove material, clean, then clear before dismantling.
Traps
- Thinking encapsulation is a substitute for removal in all cases; encapsulation is limited to intact material and requires monitoring.
- Forgetting to maintain negative pressure and verify it with a manometer.
- Skipping clearance air sampling before removing containment.
- Confusing gross removal with final cleaning; visible debris must be gone before clearance.
Rule of thumb
Order of operations: contain, depressurize, wet, remove, bag, clean, verify, dismantle. If any step is out of order in an answer choice, it is usually wrong.
Worked example
A crew wants to remove a small section of intact floor tile. Rather than a full containment, a glove bag or mini-enclosure with wet methods and HEPA vacuuming may be appropriate for a small, localized job, provided the material is non-friable and work practices prevent fiber release.