Often we encounter clients that are confused by the different information they receive from inspection companies regarding the number of samples required during their asbestos survey. So, this lends to the question “How many asbestos samples is the right amount?” In this blog, we explore the requirements for asbestos sampling.
About Asbestos
Asbestos was used due to its resistance to heat, water proofing, corrosion and its durability in a variety of applications. Once it became clear that asbestos at any level of exposure is harmful to humans, laws were put in place to reduce people’s contact with this hazardous substance.


Asbestos Inspection needs to be done right to ensure safety!
Asbestos was partially banned from its production and laws were enacted to regulate its safe management, construction practices, and improving awareness of its presence. Asbestos remains in buildings that existed prior to the origination of these rules, and it is still available in some products on the market more information can be found at: US Federal Bans of Asbestos.
When is Asbestos Sampling Required?
Renovation or demolition of buildings, or any other activity that might disturb suspect asbestos-containing material requires an inspection by EPA accredited individual to perform the survey and assessment. When determining the number of samples needed for your project it is important to realize that our asbestos survey/ inspections are performed according to the ASTM E2356-14 “Standard Practice for Comprehensive Building Asbestos Survey” which is in compliance with the EPA CFR 40 Part 61 subpart M National Emission Standards for Hazardous Air Pollutants (NESHAP).
Who Performs Asbestos Sampling?
Many of us have heard the term “the fox watching the henhouse.” This comes into play with asbestos testing and inspections when the abatement contractor attempts to do their own testing. The EPA has a strict conflict of interest requirement that consultant firms independent of the abatement contractor must complete the inspection. This makes sure that your asbestos survey is non-biased by a company who is not also doing the remediation. Additionally, states require that the individuals conducting the asbestos assessment obtain the proper accreditation, experience and education. Sampling should only be completed by an experienced testing firm.
Asbestos Sampling Rules
During an asbestos assessment, the EPA, along with other regulatory agencies (it varies by location), require that each homogeneous group of suspect asbestos-containing material be inventoried and categorized. This involves items that are different types, colors, size and date of application. A certified inspector must then collect separate sets of samples from each type of material or assume that the material contains asbestos. Samples should be categorized and taken as follows:
- Miscellaneous– includes such products as flooring, ceiling tiles, caulking, mastics, wallboard (sheetrock), shingles, glazing and grout.
- Miscellaneous suspect Asbestos Containing Building Materials (ACBM) should be sampled “in a manner sufficient to determine” per homogeneous area of the materials – the industry standard is 3 samples per homogeneous area.
- Floor tiles should be sampled per tile, color and size.
- Ceiling Tiles should be sampled by color, dot pattern and size.
- Resilient Flooring Materials- The inspector can assume that non-friable materials contain asbestos. If the inspector opts to sample the floor tile, mastic or vinyl sheet flooring it should be done in a manner sufficient to determine.
- Thermal Systems Insulation (TSI)- includes materials that are put around boilers, pipes, ducts or tanks to avoid heat loss.
- The protocol for taking samples from TSI is that there should be a minimum of 3 samples collected per mechanical system and 1 sample for patched sections if it is less than 6 linear feet or 6 foot2. To identify a patched section it must have a different color or texture from the rest of the system – this would indicate that it has it’s own homogeneous area. The rule is to take samples “in a manner sufficient to determine” of mudded fittings “per mechanical system”. This is important to note because “per mechanical system” can include parts or subparts of a system for example breaking the system into heat/ cold source, distribution lines, and return lines. The reason for the subdivision of a system is that each sub-system would have different insulation needs and therefore different types of insulation and/or different percentages of asbestos in the material.
- When are samples not needed? No samples need to be collected from any homogeneous area of TSI if the accredited inspector determines that it is fiberglass, foam, rubber or other non-ACBM. The inspector must determine that the insulation is non-ACBM and the burden of proof, as well as, the responsibility lies with the accredited inspector, so he/ she must be confident with his/ her method of determination. Non-ACBM insulation on duct work and pipes have been found to have asbestos containing paper underneath the non-ACBM insulation. Some jackets or mud applied over non-ACBM insulation has been found to contain asbestos, therefore when in doubt sample the material.
- Surfacing Materials– includes materials that have been sprayed on or otherwise applied to surfaces such as acoustical or fireproofing purposes.
- Surfacing materials are the biggest concern in the regulation because of their friability and/ or presence in public areas. The EPA funded the production of a guidance document for sampling friable asbestos containing materials that was published in 1985. This was years prior to the AHERA regulation. This document was entitled “Materials” This document is often referred to as “Pink Book”. Many of the recommended practices in this document were adopted by the AHERA Final Rule as regulations. The main recommendation adopted by AHERA (and thus OSHA by reference) was the number of samples to be taken for surfacing materials as follows:
- 3 Samples if the material is <1000 square feet.
- 5 Samples if the material is between 1000-5000 square feet.
- 7 Samples if the material is >5000 square feet.
- Surfacing materials are the biggest concern in the regulation because of their friability and/ or presence in public areas. The EPA funded the production of a guidance document for sampling friable asbestos containing materials that was published in 1985. This was years prior to the AHERA regulation. This document was entitled “Materials” This document is often referred to as “Pink Book”. Many of the recommended practices in this document were adopted by the AHERA Final Rule as regulations. The main recommendation adopted by AHERA (and thus OSHA by reference) was the number of samples to be taken for surfacing materials as follows:
Why So Many Samples?


If you’re wondering why more than one sample needs to be taken of a homogenous group, consider the chocolate chip cookie analogy. When you bite into a chocolate chip cookie, you might not actually get a chocolate chip, or you might get several. The same is true with asbestos-containing materials – you may or may not get what you are looking for or an accurate representation with just one sample due to the manufacturing process.
To add to this, depending on the types of material there may be a need for different types of analysis and analytical tools to meet all of the regulatory requirements and the latest industry standards. One thing is for sure, if your inspection firm completes the asbestos removal work, and they only take one or two samples of all the materials, you may have a problem.
The rules discussed above are just an overview. Ultimately it takes a qualified, accredited inspector from an independent firm to know what is right for asbestos sampling. Requirements can also vary by state and for some materials, it really requires an experienced professional to ensure proper sampling methods and numbers of samples.
Questions About Asbestos Sampling Methods & Requirements?
Dynamic Inspections LLC has the expertise with the applicable regulations, knowledge of how to assess an environment and the materials within, and solid practice with sampling techniques allows us to hold strong to our philosophy of providing the most efficient services possible while meeting the appropriate regulatory needs of our clients. Click here to learn more about our asbestos services.