Asbestos 101: Low Risk, Medium Risk and High Risk Abatements
James Watson
Collaborating with Housing, Pre-Employment and Band Council members to combat the challenges of Indigenous housing | Mold awareness, testing, and remediation training | FOUNDER, CEO AND TRAINER at got mold?™
Asbestos removal procedures are defined by three different abatement levels. Depending on the risk level of the asbestos containing materials, the job will be defined as a low risk abatement, medium risk abatement, or a high risk abatement.
Each abatement level has an escalating amount of safety procedures to ensure a safe removal of asbestos from the area. These procedures are in place to protect the workers on the job site and also to ensure a proper removal of asbestos from the area.
Today's article focuses on the three asbestos abatement levels, which materials pose the highest risk levels and the procedures that must be followed if your job is defined as a low risk, medium risk, or high risk asbestos abatement.
Low Risk Abatement
Low risk abatements do NOT require a containment. Often simple banner tape can suffice to keep people out of the abatement area.
Air monitoring must be done at the commencement of the project to make sure that air borne fibers are within the accepted limits. Materials to be removed should be wetted with a surfactant to inhibit asbestos fibers from becoming airborne
Tyvek suits and a ½ mask with P100 filters are the minimum PPE required for a low risk abatement job.
Medium Risk Abatement
Medium - also referred to as moderate - risk abatements require a containment. This means all materials not being removed must be covered.
A three stage chambered exit must be set up with a dirty room, transfer room, and clean room. All materials leaving containment must be bagged, wiped down and then double bagged in yellow asbestos bags.
All workers leaving a medium risk containment must wet wipe themselves off with a cloth soaked in soapy water.
Any clothes worn in a medium risk abatement must stay in containment and are considered contaminated materials.
Air monitoring is mandatory inside the containment, outside the containment and in the clean room, and one daily occupational exposure test done.
Negative air pressure must be maintained throughout the abatement.
Medium risk asbestos materials include: Drywall mud, decorative plasters, roofing shingles and wall board.
High Risk Abatement
The protocols and sophistication of containments for high risks abatements are significantly more strict, due to the heightened risk of handling high risk asbestos containing materials.
A three stage containment, consisting of a dirty room, transfer room, shower unit and clean room must be set up for all high risk asbestos abatements.
The Minimum PPE required for a high risk abatement is a PAPR full face mask, with P100 filters.
A shower unit equipped with a 10 micron filter is required to keep asbestos out of the water supply.
Workers must be naked under the Tyvek suit, and must shower before leaving the containment area to clean off potential asbestos fibres.
All materials leaving the containment must be bagged, the bag containing the materials must then be washed and placed in a clean bag in the transfer room.
Air monitoring must be set up inside, outside and in the clean room.
In addition to extensive air monitoring, a daily occupational sample taken to ensure the safety of the work area.
If the daily occupational test of the air quality comes back higher than the acceptable OEL, workers must up their PPE to a self-contained breathing apparatus (SCBA) for the remainder of the abatement to ensure safety.
Negative air pressure must be maintained throughout the duration of the abatement.
Materials considered as a high risk abatement include: Linoleum, popcorn ceilings, vermiculite, boiler insulation, pipe wrap, ceiling tiles, and spray on asbestos insulation.
got mold?™ Asbestos Services
At got mold?™ we offer a full range of asbestos services to help ensure a safe renovation, construction, or demolition project.
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got mold?™ Asbestos Services:
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If you suspect asbestos containing materials on your residential, commercial, industrial or institutional building contact the got mold?™ team at 1.888.909.MOLD [6653] or via our website to protect yourself, your employees or your loved ones.
Senior Occupational Hygienist
6yHi James, you don't need the 2-day asbestos course to work in a moderate-risk containment in Alberta. You only require the 2-day course/ticket if you are entering into a Restricted Area, which is an area that might exceed the OEL. You should never exceed the OEL in a moderate-risk containment. If you do, then the work becomes high-risk. Cheers!
Construction Superintendent at Arbutus Landscaping Inc.
6yJames, I agree with most of your information but some of the statements are incorrect. At least in Alberta.