Concrete

Cutback Adhesive & Asbestos ID

Black cutback adhesive and old resilient tile can contain asbestos, and you can't tell by looking. What OSHA and EPA presume, how to get it tested, and what changes if it's positive.

Updated · 4 min read

Safety

This guide is general information, not a substitute for the regulations or a qualified professional. Follow OSHA's silica standard for construction (29 CFR 1926.1153) and OSHA's asbestos rules for construction, and use an EPA-accredited asbestos professional for testing and abatement. State and local rules may be stricter.

Black cutback adhesive and the tile laid over it are the most common asbestos surprise on a flooring tear-out. You cannot identify asbestos by color, age or feel. The only answer is a lab result, and until you have one, federal rules tell you to treat the material as if it contains asbestos.

Stop before you grind, blast, sand or scrape

Do not disturb old resilient flooring or black mastic until it has been sampled by a qualified inspector and analyzed by an accredited lab. If it is positive, removal is regulated asbestos work under OSHA 29 CFR 1926.1101 and may trigger EPA NESHAP requirements.[1][4] This guide is general information, not legal or abatement advice.

What cutback adhesive is

Cutback is an asphalt-based adhesive thinned with solvent. It dries black or dark brown and was widely used under asphalt tile, vinyl-asbestos tile (often the 9" x 9" size) and some wood floors. Many older cutback and resilient flooring products contained asbestos fibers. Newer black adhesives may not, which is exactly why appearance tells you nothing.

What the rules presume

Federal rules start from the assumption that old resilient flooring and its adhesive contain asbestos. Each rule below covers a different piece of that.

  • Flooring installed in 1980 or earlier. OSHA treats asphalt and vinyl flooring from those years as asbestos-containing unless it's shown not to be (1926.1101(k)(1)).[1]
  • Flooring of any age. When vinyl or asphalt flooring comes up, OSHA has you assume the flooring, its mastic and its backing contain asbestos until an industrial hygienist finds otherwise (1926.1101(g)(8)(i)).[1]
  • How the work is classified. Removing asbestos floor tile, sheeting and construction mastics is Class II asbestos work, which requires a trained competent person and specific work practices.[1][2]
  • When it becomes regulated material. Under EPA NESHAP, resilient floor covering with more than 1% asbestos is Category I nonfriable material. Once it's sanded, ground, cut or abraded, it becomes regulated asbestos-containing material (40 CFR 61.141).[4] Grinding or shot blasting positive mastic is exactly that. Your state or local air agency administers NESHAP notification and disposal rules.

How to get it tested

Testing is the only way to know what you're dealing with, and how you sample matters as much as the lab you send it to.

  1. Use an accredited inspector. Many states require a licensed or EPA-accredited inspector to collect samples in commercial buildings. The EPA asbestos site links to state programs and to finding accredited professionals and labs.[3]
  2. Sample every layer separately. Tile, sheet backing, mastic, and any old patch or leveler are different materials. A negative tile does not clear the adhesive under it.
  3. Use an NVLAP-accredited lab. Bulk samples are normally analyzed by polarized light microscopy (PLM) under EPA/600/R-93/116. Labs doing this work are accredited through NIST's NVLAP program.[6]
  4. Don't trust a single negative PLM on tile or mastic. Floor tile and mastic are non-friable organically bound (NOB) materials, and the binder can hide fibers. By one state regulator's estimate, 2 to 15% of vinyl floor tile samples tested by PLM alone come back as false negatives.[5] Ask the lab for gravimetric (NOB) preparation or TEM confirmation of any negative result.
  5. Keep the report with the job file. It's your proof for OSHA, the building owner and the flooring manufacturer's warranty.

If the result is positive

Removal becomes asbestos work. In most states that means a licensed abatement contractor. The OSHA work practices for vinyl and asphalt flooring include:

Activity OSHA 1926.1101(g)(8)(i)[1]
Sanding flooring or backing Prohibited
Dry sweeping Prohibited. Use HEPA vacuums with a disposable bag and metal floor tool (no brush)
Mechanical chipping Prohibited unless inside a negative pressure enclosure
Scraping residual adhesive or backing Wet methods only
Tile removal Remove tiles intact unless intact removal is shown not possible. Wetting may be omitted when tiles are heated and come up intact
Sheet flooring Cut with the snip point wetted; wet during delamination. Rip-up is prohibited

Grinding or shot blasting positive cutback is not a flooring-contractor task. Some flooring and underlayment manufacturers publish written procedures for covering well-bonded residual cutback instead of removing it. If you go that route, follow their instructions exactly and get your abatement consultant's sign-off.

If the result is negative

Keep the lab report on site and pick a removal method for the job size:

Common mistakes

Most asbestos problems on flooring jobs start with a shortcut taken before the lab report comes back.

  • Sampling only the tile. The mastic is a separate material and often the positive one.
  • Assuming newer means safe. OSHA's 1980 cutoff is a presumption, not a guarantee, and it only covers asphalt and vinyl flooring.[1]
  • Test-grinding a small patch "to see what's there." If it's positive, you've already created regulated material and an exposure.
  • Shop vac cleanup. Standard vacuums exhaust fine fibers. OSHA calls for HEPA vacuums on this work.[1]

Regulations and references

These are the rules and guidance this article draws on. Read them for the full requirements.

  1. OSHA 29 CFR 1926.1101, Asbestos (construction), full text
  2. OSHA: Asbestos in construction
  3. EPA: Asbestos, including state programs, accredited professionals and labs
  4. EPA: Asbestos NESHAP, 40 CFR Part 61 Subpart M
  5. Maine DEP: Analysis protocol for non-friable organically bound materials
  6. NIST NVLAP: Bulk asbestos analysis accreditation

Linked PDF documents are archived copies saved by PreFloor Tools so they stay available if the publisher moves or removes them. Check the publisher's website for the latest revision.

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