For Surfacing Material: TSI, how many samples are generally required to prove not ACM?

For Surfacing Material: TSI, how many samples are generally required to prove not ACM?

• A. 1
• B. 3
• C. 4
• D. 5

Answer: (B)

When you’re trying to prove a surfacing material isn’t asbestos-containing, you must use representative sampling because asbestos distribution in spray-applied surfaces is not uniform. A single sample can miss pockets that do contain asbestos, so results may be misleading. Three samples from different locations across the area provide a practical and accepted level of confidence that the material is not ACM. If all three samples test negative, you can reasonably document that the material is not ACM. If any sample tests positive, the material is considered ACM and must be handled accordingly.

When you’re trying to prove a surfacing material isn’t asbestos-containing, you must use representative sampling because asbestos distribution in spray-applied surfaces is not uniform. A single sample can miss pockets that do contain asbestos, so results may be misleading.

Three samples from different locations across the area provide a practical and accepted level of confidence that the material is not ACM. If all three samples test negative, you can reasonably document that the material is not ACM. If any sample tests positive, the material is considered ACM and must be handled accordingly.