Tom Lent | February 21, 2010
This blog post, originally shared in the Pharos Signal, includes information about parts of Pharos that are no longer available. Please use it for historical reference and for the other useful information it contains.
Pharos Project users may have noticed that products that are advertised as no- or low-VOC, are not necessarily rated highly in Pharos. For most interior finish products, Pharos scores a product based on whether it passes a 14-day test for emissions of VOCs* such as FloorScore, GreenGuard or Indoor Advantage. The system then deducts points for content of chemicals of concern that are flagged in the Pharos Chemical and Material Library. This addresses the non-volatile, toxic chemicals that occupants are exposed to, but the VOC tests don’t measure. Pharos puts a higher weight on the most hazardous of the VOC chemicals.
Pharos evaluates wet applied products, such as the recently-added high performance coatings (including paints, caulks and adhesives) a bit differently; starting with a score based upon the content of VOCs instead of emissions tests. Some of the VOC emission testing programs do certify these products, but these wet products act differently from carpets and particle board, releasing a big blast of hazardous VOCs during the first hours and days of use that these long-term emissions tests aren’t able to tell us much about. At this point, there is lots of disagreement in the emissions lab world about how best to measure and evaluate these short-term VOC releases from wet products.
While the emissions world is working on this problem, Pharos is using the VOC content (sometimes called TVOC for total VOC) to compare products.
Several issues make TVOC a less than perfect protection for human health:
Pharos staff continues to support efforts to develop improved measures to evaluate both content and short-term emissions of VOCs, and will apply more advanced measures as they are developed.
*VOCs are the Volatile Organic Compounds that outgas from materials after they are made – creating that new carpet smell and releasing toxic gases into your air.