How to Interpret Asbestos Testing Results
It is very easy and inexpensive for the private individual to send samples to a lab for asbestos testing, but a common problem that occurs is in trying to interpret the results that are received back. Asbestos testing reports usually do not do much to explain the results, and the average Joe sometimes feels lost. This article goes over the basics of how to interpret asbestos testing results.
(You may want to check out this article on How to Asbestos Testing to see how easy it is to take the sample yourself and submit it to a lab)
The Lab Report
Asbestos Testing Report Example
The lab report will sometimes have a lot of extraneous information relating to the optical data used to identify the components and may even list all the types of materials present in the sample. A lab’s accreditation requires that this data be reported, but some reports are better designed than others at providing a clear-cut summary. Many reports will use a summary page, then dump the extraneous information on back pages.
Caution is required in trying to look through this extra detailed information. One area that may mislead an inexperienced reader is that the labs are required to characterize the sample at low magnification first, then go onto high magnification. A lab might report that no asbestos was visible at low magnification (stereoscopic exam), then turnaround and report that asbestos was present at high magnification (PLM exam). Do not let the low magnification data fool you into believing a material is asbestos free.
Low Mag (Stereoscopic) reports ND (None Detected) while High Mag (PLM) reports 3% Chrysotile asbestos
The two key things that are often reported on the summary page are:
• What kind of asbestos it is
• How much asbestos is present
What Type of Asbestos
To a large degree the type of asbestos really does not matter that much. There are six types of asbestos:
• Chrysotile
• Amosite
• Crocidolite
• Tremolite
• Actinolite
• Anthophyllite
These are listed in order of how common they are. Chrysotile is mined in Canada and was used extensively in North America. Chrysotile is also more silky or cottony than the others and found its way into more products.
There have been arguments made that Chrysotile is the least dangerous for various reasons, but it is difficult to really determine. Legally they are all asbestos and all just as dangerous.
How Much Asbestos is Present
If there is no asbestos present, the asbestos testing report will usually say “None Detected” or “ND”. If there is asbestos present then the report will express this in terms of how much of the sample is asbestos. For example if a material is composed of half asbestos and half paper fiber, the summary result will say something like “50% Chrysotile”.
The regulatory threshold is 1% asbestos in most US states except California (where it is 0.1%). Labs will often not try to quantify the amount of asbestos if it is below 1% and will just report “<1%” (less than one percent).
If quantification below 1% is required, then a point count analysis often is used. This is just a more complicated (and expensive) test where more of the sample is analyzed statistically. Whether it really gives a better result is open to scientific debate, but legally the US EPA says it is better. A point count is usually only used when a sample is near the 1% threshold.
How Much Asbestos is Bad
1% asbestos is often the regulatory threshold that determines whether a material is considered asbestos-containing or not. If a material has less than one percent asbestos, then for the most part it is free from regulations (unless you are in California).
This means that a public school, an apartment building, or a public building can dispose of the material anyway they see fit without having to use licensed professionals (private homeowners are generally not bound by these regulations.)
This 1% threshold is not based upon health data however. This value was chosen based upon how good the technology available was at detecting asbestos. It was decided that the various technologies that would be used to detect asbestos for regulatory purposes would not be that consistently accurate below 1%.
For this reason most labs will not bother to try and quantify below 1% on their asbestos testing reports unless specifically asked (for most samples, asbestos can be detected below this 1% threshold, but the quantification is often not very precise.)
This does not mean that <1% is necessarily safe or that 2% would necessarily be dangerous.
Assessing the Danger
The key thing with asbestos is how likely it is to become airborne and inhaled. Asbestos exposure can lead to Asbestosis and Mesothelioma, a particularly bad form of cancer, but fibers must make their way into the lungs first. Some materials with 10% asbestos might be safer than materials with 2% asbestos.
The key is how likely the material is to give off fibers and dust. A material made out of tar is not likely to give off much fibers unless it becomes really dried out and damaged. Other materials may be more easily damaged and therefore more easily create asbestos dust in the air. Most materials that do not ever get damaged or disturbed will not give off asbestos dust.
Do Not Disturb
To a large degree, common sense can guide you here. If asbestos is in a material that never gets touched or disturbed then there is less concern. If it is in your “popcorn-style” ceiling texture that your kids are constantly knocking to the floor, then there is more concern. Once asbestos gets into the dust, it tends to stick around and be easily stirred up into the air.
The key is not to damage and disturb it, and often a problem only arises if you decide to do remodeling. Private homeowners are not bound by NESHAP regulations, but just about everyone else is, including apartment dwellers. Home owners are free to remove the asbestos themselves as long as they follow certain rules, but this is generally not recommended.
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Conclusion
An asbestos testing report can be confusing if you do not know what to look for. The key item to look for on asbestos testing report is whether there is asbestos present or not. If it is present, the asbestos testing report does not do much to interpret the results for you. At this point you must determine for yourself how likely the material is to release asbestos dust depending on the condition of the material and how likely it is to become disturbed or damaged.
Check out our page on Asbestos Testing page and our How To Asbestos Testing page.
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