Where Do Primers Fit in the VOC Limits?

I was just asked today about what the VOC limit is for primers to help achieve EQc4.2, Low-Emitting Materials, Paints & Coatings. A CIR ruling (for NC 2.0/2.1, none listed for NC 2.2) states the following: 3/14/2003 - Ruling The Green Seal Environmental Standard for Paint (GS-11) is the standard on which achievement of this credit is based. All paints used on the project must meet these standards to achieve this credit. According to Green Seal, primer is classified as a topcoat for purposes of this standard and must comply with the requirements as well. So... the primer definitely must meet the standard. The question now is whether it's flat (50 g/l) or non-flat (150 g/l). I have a hard time believing that it would be non-flat, but then again, primers are never really listed either way. I tend to err on the side of durability, not LEED, and I could definitely see where additional VOC's (which sort of serves as a proxy for performance) would help improve adhesion. After reading through a PPG created guide spec, I get the impression that these primers qualify as non-flat finishes. They repeatedly exhibit awareness of the different requirements between flat and non-flat paints, but in most cases the primer (including multiple series and substrates) is between 50-150 grams/liter. See page 6 for the spec, page 23 for LEED COMPLIANT OPTIONS. Note, for gyp board and other surfaces they often offer a zero voc option... while potentially expensive, there would be no doubt about compliance...

CORRECTION!!! HUMBLE PIE SERVING NUMBER 2!!!

Primers must meet the limit for NON-FLAT paint with a 150 g/l VOC max.

Alert reader Josh Greenfield once again has pointed out something I missed. He was smart enough to search through the latest LEED-NC Reference Guide Errata Sheet (page 11), where it definitively states that primers are to be considered non-flat paints.

If I had been so smart this would have been a much shorter post. Due to the corrections some of the unecessary portions of the original post has been removed.

2 comments:

kerry said...

The 2nd edition of Green Seal Standard GS-11 calls for a 100g/l limit for non-flat paints.
http://www.greenseal.org/certification/standards/paints_and_coatings.pdf
Do you think it's safe to assume the 2003 edition limit of 150g/l for non-flat paints still stands until the USGBC updates the requirement?

Raph said...

GS 03 rule refers to anticorrosive coatings without specifying if primers are included. In SCAQMD rule, a primer is defined as a coating. Can we assume that the limit of 250 g/l for anticorrosive coatings can also be applied for anti-corrosive primers ?