Response Actions and Abatement Methods
The menu of responses
Response actions range from operations and maintenance (O&M) for material in good condition that will remain, through repair, enclosure, encapsulation, and removal. Removal is generally preferred where the material will be disturbed, where the building will be demolished, or where condition is poor. Each method has a design consequence: enclosures create a hidden space that future workers may penetrate; encapsulants must be compatible with the substrate and may not be applied to damaged or friable material without repair; removal generates the largest waste stream and the strictest containment.
Traps
Questions often present encapsulation as a cure-all. Encapsulation does not remove the hazard and is inappropriate on significantly damaged or crumbling material. Another trap is confusing enclosure (a physical barrier) with encapsulation (a coating). For removal, know the hierarchy of controls and the difference between glove-bag work on small fittings and full negative-pressure containment for large areas. Also expect questions on aggressive vs. non-aggressive final cleaning and on when a critical barrier must be maintained.
Rule of thumb
Match the response to the disturbance: material that will be disturbed should generally be removed before the disturbance, not encapsulated. Worked example: a boiler room with friable insulation scheduled for pipe replacement - removal inside containment is the defensible design; encapsulation would be defeated by the very work planned.