Definition
A liquid product applied to in-place asbestos-containing material (ACM) to create a protective coating or membrane that prevents fiber release. Two types exist: penetrating encapsulants, which are absorbed into the ACM and bind fibers internally, and bridging encapsulants, which form a tough surface membrane over the material. Encapsulants are used when ACM is in reasonable condition and will not be disturbed, as an alternative to removal. They do not eliminate asbestos; the material remains in situ and must be maintained, re-inspected periodically, and recorded in the asbestos register. Encapsulants differ from lockdown agents: an encapsulant treats ACM that is being left in place, while a lockdown is applied after removal to seal residual fibers on stripped surfaces.
See also:
Asbestos Encapsulation
Asbestos encapsulation is a method of asbestos abatement that controls fiber release by treating asbestos-containing materials (ACMs) with a sealant rather than removing them. Two product types are used: penetrating encapsulants (absorbed into the ACM to bind fibers from within) and bridging encapsulants (forming a protective membrane over the surface). To encapsulate asbestos correctly, the material must be in good condition and not subject to future disturbance — encapsulation does not eliminate asbestos, it temporarily prevents fiber release. Encapsulated materials must remain in the asbestos register, be inspected at regular intervals, and have the encapsulant condition recorded at each inspection. Long-term management obligations persist: any future renovation, refurbishment, or demolition requires the ACM to be removed before work begins. Most national regulations require that encapsulation of licensed asbestos materials be carried out by certified or licensed contractors.
Lockdown (Fiber Binding Agent)
A fluid liquid applied to surfaces after asbestos removal to bind and immobilize any residual fibers that may remain despite thorough cleanup. Also known as a fiber binding agent. Lockdown is the final step in the abatement process: once all bulk ACM has been removed and the area wet-cleaned and HEPA-vacuumed, a lockdown agent is sprayed or rolled onto exposed substrates (walls, ceilings, structural members). The liquid penetrates rough surfaces and cracks, and upon drying forms an elastic, neutral layer that locks remaining microscopic fibers in place and prevents air recontamination. The treated surface must then pass visual inspection and air clearance testing before the containment is dismantled and the area reoccupied. Reference products: CEMBLOK BASE (Deconta). May also be applied to fiber-cement materials (such as asbestos-cement roofing) before or during handling to suppress hazardous dust. Lockdown differs from encapsulant: a lockdown seals surfaces after removal, while an encapsulant treats ACM that remains in place. Differs from wetting agent: a wetting agent saturates material before intervention, while lockdown is applied after removal.
Wetting Agent
A liquid applied to asbestos-containing materials before intervention to saturate and moisten them in a controlled manner, minimizing fiber release and dispersion during cutting, drilling, or sample collection. The agent is injected or sprayed onto the exact area where work will take place, binding fibers completely before the material is disturbed. Reference products: Astrip (Deconta), used with the Safestrip system. A wetting agent differs from an encapsulant and a lockdown agent in its timing: the wetting agent acts before intervention, the encapsulant treats ACM left in place, and the lockdown seals surfaces after removal.
ACM (Asbestos-Containing Material)
ACM (asbestos-containing material) is any material with more than 1% asbestos by weight. At peak use, ACMs appeared in over 3,000 different products: insulation, fireproofing materials, roofing, flooring, and cement products. Buildings must be surveyed for ACMs before renovation or demolition, and any found must be managed or removed to protect occupants and workers.
Friable Asbestos
Asbestos-containing material that can be crumbled, pulverized, or reduced to powder by hand pressure when dry. Friable asbestos releases fibers more readily than non-friable asbestos and is therefore considered more dangerous. Common examples include pipe insulation, spray-on coatings, and thermal insulation. Friable materials require specialized handling, removal, and strict containment.