|Mold in Buildings
I’m writing to correct an erroneous statement made by Robert Barone, RA, and Katie Schwarting in the article “Surveying Mold in Buildings” in the June issue of SN. It’s ironic that authors who state in the second paragraph of their article: “The overarching problem with respect to mold has been a lack of reliable information,” should a few sentences later make a totally inaccurate statement.
By writing: “Many substances commonly used in the construction of buildings and homes wood, paper covering for drywall, and cellulose insulation, to name three of many provide ample sustenance for mold” the authors displayed a lack of knowledge of the nature of cellulose insulation. They committed the error of seeing “cellulose” in “cellulose insulation” and instantly thinking “mold.” They are apparently unaware that all cellulose insulation contains boric acid at concentrations ranging up to 20 percent by weight for materials intended for enclosed installation and up to 24 percent for cellulose commercial sprays (Type I material per ASTM C 1149, Specification for Self-Supported Spray Applied Cellulosic Thermal Insulation), which are intended for exposed or enclosed application and represent the material most likely to be found in buildings addressed by E 2418, Guide for Readily Observable Mold and Conditions Conducive to Mold in Commercial Buildings: Baseline Survey Process. Boric acid is incorporated in cellulose insulation as a fire retardant, but it has the convenient side effect of making the material inhospitable to mold colonization.
Mold can grow on anything, including cellulose insulation under extreme conditions, but it will grow on everything else in sight before it colonizes the insulation. As one of the nation’s leading mold and indoor air quality experts commented to me at a conference several years ago: “With the boric acid you put in it’s hard to make mold grow on that stuff!”
Other comments by knowledgeable experts include the following.
Jeff May, a nationally known home inspector and author of the book My House Is Killing Me, wrote in a posting on the IAQ mailing list: “I have yet to see a moldy cellulose insulation sample. I imagine mold growth occurs where there has been constant water and the antimicrobials have been leached out, but in general blown in cellulose insulation, surprisingly, is not found moldy.”
Southface Journal, a publication of Atlanta’s respected Southface Energy Institute, in an article “Debunking Mold Myths” stated: “Please note that some scientists will refer to all plant based fibrous materials as ‘cellulose.’ This use of the word does not apply specifically to cellulose insulation, but rather to the general category of wood-based building materials like drywall, oriented strand board (OSB), and framing. Insulating with cellulose insulation does not increase the risk of mold problems but rather, if properly installed, will actually reduce the risk of mold growth.”
Members of the cellulose segment of the insulation industry have been active, contributing members of ASTM International for many years. I have been a member for nearly two decades. Currently, 21 members of Committee C16 on Thermal Insulation are from cellulose insulation manufacturers and their suppliers. ASTM members representing cellulose insulation interests have served and currently do serve as officers of C16 and as chairs and secretaries of C16 subcommittees and task groups. We do not expect the Society to be a conduit for damaging, inaccurate claims about our product.
Cellulose Insulation Manufacturers
Association, Dayton, Ohio
Member, Committees C16 on Thermal Insulation and E05 on Fire Standards