Asbestos abatement: 0.1 fiber per cc and the clearance

The asbestos limit is 0.1 fiber in a cubic centimeter of air, and a cubic centimeter is a sugar cube. A single square foot of dry pipe insulation, broken, puts out fibers by the million.

The points

• Asbestos gives you mesothelioma and lung cancer 20 to 40 years after the job, and the dose does not have to be large. The people who did this work in the 1970s without wet methods are the reason the rule exists.
• The rule sorts the work into four classes. Class I is pipe and boiler insulation and sprayed-on material; Class II is floor tile, roofing, siding and wallboard; Class III is repair work that disturbs it; Class IV is cleanup around it. Each class has its own controls.
• Every Class I, II and III job is a regulated area: signs, limited entry, no eating or smoking, respirators on everyone inside whenever the rule requires them, and on Class I that is always, and a competent person who has been through the training and has the authority to stop the work.
• Wet it before you touch it and keep it wet. Amended water, a garden sprayer, and material that is dripping, not damp. Dry removal is a violation and it is how fibers get airborne in the first place.
• Waste goes in 6 mil bags, sealed, with the DANGER asbestos label on every bag, and the glove bag gets used once and never moved. The job is not done until the clearance air sample comes back from the lab.

Why it goes wrong

The PEL in 29 CFR 1926.1101 is 0.1 fiber per cubic centimeter as an 8-hour average, with a 30-minute excursion limit of 1 fiber per cc. You cannot see, smell or feel any of that; a room that looks clean can be over the limit. That is why the rule assumes Class I work is over the limit until air monitoring proves otherwise, and Class II work with no negative exposure assessment still needs respirators.

Class I work goes inside a negative pressure enclosure or a glove bag. The enclosure runs at minus 0.02 inches of water column and four air changes an hour, smoke tested before you start. The glove bag is 6 mil, seamless at the bottom, used once, not used above 150 °F, and needs two people on it, one working and one watching the bag.

The competent person on an asbestos job is a specific role with specific training. They set up the regulated area, check the containment, supervise the air monitoring, verify respirators and decon are being used, and make sure notifications went out. On a Class I or II job that person is on site, not on the phone.

Decon is the shower, the clean room and the dirty room. Suits come off inside the dirty side, you shower, then dress on the clean side. Fibers ride home on hair, in eyebrows and in the seams of a boot, and family members of asbestos workers have gotten mesothelioma from laundry.

The EPA side is 40 CFR 61 Subpart M, the asbestos NESHAP. At or above 160 square feet, 260 linear feet of pipe, or 35 cubic feet of regulated material, the owner or contractor files a written notice at least 10 working days before the work, and the material stays adequately wet until it is sealed in a container. A state or county program usually adds a licensed contractor and a licensed supervisor on top.

Clearance is an air sample by an independent person after the visual inspection passes and the containment has been cleaned and wiped. Do not pull the poly on a passed visual alone. If the sample fails, the containment stays up and you clean again, which is far cheaper than a family living in a failed clearance.

Questions for the crew

1. What class is the work in that room, and who is the competent person on this job?
2. Where does the wet come from today, and what happens if the sprayer runs dry mid-shift?
3. Who is running the clearance sample, and what do we do while we wait for the lab?

To close

Nothing on this job gets removed dry today, and nothing gets bagged without the label.