4 PCH Testing and SBR Verification

4-PCH was my Masters Thesis in the mid-1980s. If anyone cares for a longer discussion, I know why it is in LEED and why it shouldn't be. Nevertheless, 4-PCH is a side reaction when polymerizing styrene and butadiene (combining styrene and butadiene that don't polymerize makes 4-PCH), which are the "S" and "B" in SBR, to create latex backings in carpet and other materials. When I do the LEED air testing I use a method that can have 4-PCH included typically for no additional charge. The method is EPA TO-17. I use the Radiello passive sampler and have it analyzed for the individual compounds present including total VOCs. This helps identify the VOC culprit(s) if the samples fail LEED criteria. With this information I can make recommendations on what to do to help the sampling pass the follow up tests. I have a presentation called "Eight Ways to Fail Your LEED Air Testing" which includes mostly VOC issues. Also, MSDSs are not very reliable and often incomplete. Hopefully this will change with the implementation of the new OSHA Hazard Communication standard which requires global harmonization and specific items be included in what are to be called Safety Data Sheets (SDSs). This should be fully implemented within the next two to three years. My bottom line recommendation would be to include 4-PCH in your air testing and have the TVOC samples analyzed for all the VOCs present, including Tentatively Identified Compounds (TICs). The likelihood that 4-PCH will be present is very low. Modern SBR manufacturing has reduced or eliminated the side reaction that creates 4-PCH. It is an unwanted compound that indicates poor efficiency in the process.

Dale, Have you pust your viewpoint into a LEED Interpretation? The current testing methodology came out of a CIR request that was then adopted into practice (and I can't remember if it went through the LI route). It sounds like you have a lot of good technical information and an LI is one route to change or create an alternate pathway for project teams to follow once the LI is accepted. Susan

Hello Dale, What if we do not have carpets and fabrics with Styrene Butadiene Rubber (SBR) latex backing, installed as part of the base building system? Thanks, KC

With that being the case, you don't have to ask the lab to analyze for 4-PCH. Depending on the lab it shouldn't have much of an impact on the total volatile organic compounds (TVOC) analysis cost, if any. Again, I would suggest that the analysis requested for the TVOCs include the amount of the individual VOCs present with the addition of tentatively identified compounds. That way if the sample(s) fail LEED criteria you can find out what compounds were most prevalent and try to ret rid of the cause for the retest.

Thanks Dale!