NC Asbestos Abatement key terms

Any material or product that contains more than one percent asbestos by weight as determined by an accredited laboratory using polarized light microscopy. Regulators treat all such material as hazardous during renovation, demolition, and maintenance work.

Material assumed to contain asbestos until sampling proves otherwise, typically installed before the mid-1980s. Building owners may treat it as ACM without testing, and workers must handle it with asbestos precautions until laboratory analysis says no.

Asbestos that can be crumbled, pulverized, or reduced to powder by hand pressure when dry. Friability drives how easily fibers become airborne, so friable material requires stricter handling, containment, and disposal rules than nonfriable material.

Asbestos material that cannot be crumbled by hand pressure when dry, such as intact floor tile, roofing, or transite pipe. It becomes regulated when cutting, grinding, or sanding breaks the matrix and releases fibers.

Nonfriable asbestos material that is unlikely to become friable when disturbed, including packings, gaskets, resilient floor coverings, and asphalt roofing products. Handling rules are lighter than for friable material unless the material is sanded, ground, or abraded.

Nonfriable asbestos material that may become friable when disturbed, such as asbestos-cement sheet, transite pipe, and some roof coatings. It requires careful removal and handling because impact or weathering can break it into releasable fibers.

A regulatory category covering friable ACM, Category I and II nonfriable ACM that has become friable or will be disturbed, and any ACM that is sanded, ground, cut, or abraded. RACM triggers full abatement and disposal requirements.

An on-site inspection to locate, identify, and document asbestos-containing and presumed asbestos-containing materials before renovation, demolition, or maintenance. Results guide the abatement plan, worker protection measures, and notification obligations.

Collecting small physical samples of suspect material for laboratory analysis to determine asbestos content. Samples must be taken in a way that avoids fiber release, and each homogeneous area is sampled according to a defined protocol.

A surface or material that is uniform in color, texture, and date of installation, so one set of samples can represent the whole area. Correctly defining homogeneous areas prevents missed asbestos and unnecessary sampling.

The standard laboratory method for identifying asbestos in bulk samples by examining optical properties of fibers under polarized light. It distinguishes asbestos types and estimates percentage, though it can miss thin fibers in some matrices.

A more precise PLM technique that counts fibers on a prepared slide grid to estimate asbestos percentage, often used when results are near the one percent regulatory threshold. It reduces the chance of misclassifying borderline material.

A high-magnification method used to identify and count very fine asbestos fibers in air or bulk samples. It is more sensitive than phase contrast microscopy and is used for clearance testing and research-grade analysis.

The standard method for counting airborne fibers on membrane filters from air samples. It counts all fibers of a certain size, not just asbestos, so results are reported as fibers per cubic centimeter rather than asbestos fibers specifically.

The unit used to express airborne fiber concentration. Regulatory exposure limits, action levels, and clearance criteria are all stated in this unit, so reading and comparing sample results depends on understanding it.

The legally enforceable maximum airborne asbestos concentration to which a worker may be exposed over an eight-hour shift, set by federal occupational safety rules. Employers must keep exposures at or below it and monitor when levels may approach it.

A short-term ceiling on airborne asbestos exposure measured over a brief sampling period, typically thirty minutes. It protects workers from brief high-concentration bursts that an eight-hour average would not capture.

Air sampling worn by workers to measure personal asbestos exposure during abatement tasks. Results determine whether respirators are required, whether regulated areas are needed, and whether engineering controls are working.

A documented finding by the employer that worker exposure will stay below regulatory limits for a specific task, based on objective air monitoring data. It can justify reduced controls, but it must reflect actual conditions and be reassessed when they change.

A small battery-powered pump worn by a worker that draws air through a filter cassette at a calibrated flow rate. The collected fibers are counted later to calculate that worker's exposure over the sampling period.

Air sampling conducted inside a containment after abatement and cleaning to confirm fiber levels have fallen below the required threshold before the enclosure is removed. Failure requires recleaning and retesting.

A sealed enclosure of plastic sheeting and framing that isolates the work area and prevents asbestos fibers from escaping. It includes negative pressure, critical barriers, and decontamination access so that air flows inward, not outward.

A condition in which air pressure inside the containment is lower than outside, so air flows inward through leaks rather than outward. Exhaust fans with HEPA filters maintain it and must run continuously during abatement.

A temporary seal placed over openings such as doors, windows, vents, and ducts to stop air movement between the work area and occupied spaces. Critical barriers are installed before containment is built and removed last.

A high-efficiency particulate air filter rated to capture at least 99.97 percent of particles 0.3 micrometers in diameter. It is used on vacuums, negative air machines, and respirators to trap asbestos fibers rather than recirculate them.

A vacuum equipped with a HEPA filter, used to clean surfaces and equipment without releasing collected fibers back into the air. Ordinary shop vacuums are prohibited because they exhaust fine particles into the work area.

Cleaning surfaces with water or a wetting agent to keep dust down and remove settled fibers. It is combined with HEPA vacuuming during final cleaning and is repeated until visual inspection shows no residue.

A close look at all containment surfaces, ledges, and equipment after cleaning to confirm no visible dust or debris remains. It must pass before clearance air sampling begins, so cleaning problems are caught early.

A three-stage entry and exit system with a clean room, shower, and dirty room that workers pass through to remove contaminated clothing and fibers before leaving the work area. It prevents tracking asbestos into clean spaces.

Gear worn to protect the worker from asbestos exposure, including respirators, disposable coveralls, gloves, and eye protection. PPE is the last line of defense and never replaces containment or engineering controls.

A tight-fitting mask that filters inhaled air, selected according to expected exposure levels and worn with a medical evaluation and fit testing. It must be worn inside the containment and removed only after decontamination.

A procedure that verifies a respirator seals against the wearer's face, using a challenge agent or measured particle count. It is required before first use and repeated at least annually or when facial conditions change.

A sealed plastic bag with built-in gloves that encloses a small component such as a pipe section, letting a worker remove asbestos inside the bag without opening the containment. Debris and tools are bagged out through the glovebag.

A small, sealed containment built around a localized work area, such as a pipe fitting or valve, when a full enclosure is impractical. It still uses negative pressure or HEPA vacuuming and follows the same cleaning and clearance rules.

A written site-specific document describing the scope of asbestos removal, work practices, containment design, worker protection, waste handling, and clearance criteria. It is prepared before work starts and guides daily supervision.

Collecting and analyzing air samples to measure fiber levels in the work area, at the containment boundary, and in adjacent occupied spaces. Results verify that controls are working and support clearance decisions.

A tracking document that follows asbestos waste from the generation site through transport to the disposal facility, with signatures at each handoff. It creates a chain of custody proving the waste reached an approved landfill.

Wrapping or bagging removed material in leak-tight containers, labeling them clearly as asbestos, and keeping friable waste wet. Proper packaging prevents fiber release during storage, transport, and disposal.

A disposal site permitted to accept asbestos waste and required to cover it promptly to prevent fiber release. Abatement contractors must confirm a site's acceptance before hauling waste off the job.