Three Floor-Tile Samples, One Hit
An accredited inspector is conducting an AHERA inspection of a 1968 elementary school. One homogeneous area consists of 3,200 square feet of 12-by-12 floor tile in 12 classrooms. The inspector collects three tile samples; the laboratory reports 2 percent chrysotile in one sample and less than 1 percent in the other two by polarized light microscopy. The mastic beneath the tile was not sampled separately. In a crawlspace, friable thermal-system insulation on pipes could not be accessed because of standing water, so no TSI samples were collected. On the roof, a single sample of flashing cement used to patch a vent stack reports 3 percent chrysotile; the material is nonfriable where it sits. The principal wants to know whether the tile is “mostly negative” and whether the crawlspace can be left out of the management plan because nobody goes there.
1. Is the 12-by-12 floor tile ACM? Explain the AHERA sampling rule and whether the three results can be averaged. What about the mastic?
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Under AHERA, ACM is material containing more than 1 percent asbestos. For a homogeneous area of floor tile, the inspector should collect at least three samples. If any one sample exceeds 1 percent, the homogeneous area is classified as ACM; the results are not averaged to produce a “mostly negative” finding. The 2 percent chrysotile result therefore makes the 3,200-square-foot tile area ACM. The mastic is a separate material and a separate homogeneous area; it was not sampled, so it cannot be assumed non-ACM. It should be sampled, or treated as ACM until characterized. The fact that floor tile is nonfriable does not make it exempt: removal can break it and create dust, and removal is Class II work under OSHA. The principal should be told that “two out of three negative” does not make the area negative under AHERA.
2. How should the inaccessible friable TSI and the single roof-patch sample be classified and handled?
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The crawlspace TSI cannot simply be omitted because access is difficult. AHERA requires the inspector to sample each homogeneous area or assume the material is ACM; if access is unsafe, the material should be assumed ACM and managed accordingly. OSHA separately presumes thermal-system insulation to be ACM unless it has been sampled and proven otherwise. The roof flashing was sampled only once, which is insufficient to characterize a homogeneous area; moreover, one result of 3 percent chrysotile means the material should be treated as ACM until additional sampling shows otherwise. Nonfriable roofing material can become friable when cut, ground, or pried, so removal is not automatically exempt. Both materials should be entered in the management plan, labeled where feasible, and addressed before any renovation disturbs them.
3. What should the inspector recommend to the local education agency, including management-plan and re-inspection requirements?
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The inspector should recommend that the LEA update its asbestos management plan to list the floor tile and mastic, the assumed ACM in the crawlspace, and the roof flashing. The plan should include location, quantity, accessibility, condition, and response actions. Friable TSI in a wet crawlspace should be prioritized for repair, enclosure, or removal because water and access can worsen its condition. The floor tile can be managed in place if intact, but any renovation must use Class II work practices and proper worker protection. The LEA should notify parents and staff as required, label or post warning signs where appropriate, and conduct periodic surveillance every six months and re-inspection at least every three years. The principal should also be told that “nobody goes there” is not a valid basis for excluding the crawlspace from the plan.