AWPA OK’s Micronized Wood
(March 16, 2017) In the coming weeks, wood treated with micronized preservatives will officially be AWPA standardized, with the publication of the next American Wood Protection Association Book of Standards.
Previously, there were AWPA standards for the chemicals, but not for wood products treated with those chemicals. Instead, preservative manufacturers Lonza and Koppers maintained ICC-ES reports to establish and certify appropriate retention levels.
Now, wood treaters using the of two systems of micronized copper azole (MCA and MCA-C) will be able to legally claim conformance of their treated wood to AWPA Standard U1.
Nonetheless, Lonza will renew its ICC-ES report for at least one more year, to provide their customers an extended transition period and an additional option for production of a code-compliant product, since the retention levels in their report and those approved by AWPA are higher in some cases.
Koppers will also continue to reference ICC-ES. Its retentions did not change for Above Ground (.06) and Ground Contact (.15).
Producers can not switch to AWPA end tags until the changes to AWPA U1 are effective and they conform to the updated retentions and other AWPA standards and procedures.