The California Air Resources Board (CARB) recently solicited bids from contractors to analyze bulk samples using CARB’s proposed methodology for measuring naturally occurring asbestos (NOA). The proposed methodology is called “Test Method 435” or “M435”: Laboratory Testing of Asbestos Content in Rocks and Soil. CMTA and many others believe that the new methodology is flawed and should be re-examined, including a chance for public comment.

CARB’s key revisions include:

• Changing the definition of asbestos to include “asbestos particles,” which include non-fibrous, common minerals that do not cause the health effects associated with real asbestos. This extremely broad definition will lead to “false positives,” incorrectly identifying large areas of California’s common rocks and clean soil as "asbestos."
• New laboratory procedures that will result in greater confusion as to whether a rock or soil sample contains actual NOA deposits, or merely background asbestos that exists everywhere in California.

The false positives that will occur as a result of CARB’s latest proposed revisions will incorrectly label non-fibrous, common minerals as “asbestos” and will critically jeopardize California’s ability to work the land, produce construction materials, and complete public improvements. The new mandatory methodology will, in turn, put thousands of jobs at risk throughout California.

CARB needs to refine the proposed M435 test method to more accurately identify and quantify actual naturally occurring asbestos in rock and soil fragments and avoid false positives.