VOC content Methods

As per SCAQMD 1113:

For the purpose of this rule, the following test methods shall be used: (1) VOC Content of Coatings
The VOC content of coatings subject to the provisions of this rule shall be determined by:
(A) U.S. EPA Reference Test Method 24 (Determination of Volatile
Matter Content, Water Content, Density, Volume Solids, and Weight Solids of Surface Coatings, Code of Federal Regulations Title 40, Part 60, Appendix A) with the exempt compounds’ content determined by Method 303 (Determination of Exempt Compounds) in the South Coast Air Quality Management District's (SCAQMD) "Laboratory Methods of Analysis for Enforcement Samples" manual, or
(B) Method 304 [Determination of Volatile Organic Compounds (VOC) in Various Materials] in the SCAQMD's "Laboratory Methods of Analysis for Enforcement Samples" manual.
(C) Exempt Perfluorocarbons The following classes of compounds:
cyclic, branched, or linear, completely fluorinated alkanes cyclic, branched, or linear, completely fluorinated ethers
with no unsaturations cyclic, branched, or linear, completely fluorinated tertiary
amines with no unsaturations sulfur-containing perfluorocarbons with no unsaturations
and with sulfur bonds only to carbon and fluorine will be analyzed as exempt compounds for compliance with subdivision (c), only when manufacturers specify which individual compounds are used in the coating formulations. In addition, the manufacturers must identify the U.S. EPA, CARB, and SCAQMD approved test methods, which can be used to quantify the amount of each exempt compound.

What if the interior coating I use has a VOC content <1 g/l and this is certified by a test made according to the ISO 11890?
Is it valid to get the IEQc.4.2 credits?

ISO 11890-2 is the VOC standard cited in EU Decopaint Directive 2004/42/CE. The ISO method differs from the US-EPA methods cited in the SCAQMD-1113-2004 and in Green Seal Standards GS-11-1993 & GC-03-1997, as referenced by LEED-2009 for IEQc4.2. See Items 1 & 2 of Dwayne Fuhlhage's June 19 post on the Core & Shell IEQc4.2 page: http://www.leeduser.com/credit/CS-2009/IEQc4.2#comment-50943.
In that post, Dwayne recommended submitting formal inquiries to USGBC & GBCI to resolve these differences. If someone has done so, we might see clarifications when USGBC issues quarterly Addenda & Interpretations in October.

Thank you for your answer, Jon.

Since the product I'm talking about is an interior flat coating, I went through the Third Edition of the GS-11-1993 and in the 3.4 paragraph (Volatile Organic Compound (VOC) Content Limit), it says that the alternative method to test the VOC content in air-dry coatings to the ASTM D6886-03 Standard Method is the one made according to the ISO 11890-2, with the only condition that 280° must be used as a marker. As Dwayne Fuhlhage indicates in the comment you suggested me to read, the boiling point cutoff set by the two standards is different but if the test is made according to the ISO 11890-2 but with a marker of 280°, the LEED IEQc4.2. credits should be reached. Is it correct?

LEED-2009 references the 1993 First Edition of GS-11, which does not include the ASTM & ISO references that you have cited from Paragraph 4.4 of the 2011 Third Edition. The First Edition bases VOC measurements on US-EPA methods that may not be equivalent to ASTM D6886-03 (or ISO 11890-2 with adjustments) as allowed under the newer version.

We really need USGBC to issue an official clarification to resolve these questions for LEED-2009 International projects. As Dwayne suggests, you should submit a formal Credit Interpretation Request to validate your approach.