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Worst in Class Chemicals
(PDF factsheet on healthy building materials and how to find them)
All materials exist on an environmental impact continuum of varying postitive and negative impacts on human health and the environment. A wide range of environmental health policies of local and national governments and international treaty have identified a set of chemicals as warranting priority efforts to eliminate due to their high toxicity and global impact.
HBN works in the building sector to move the industry away from materials that incorporate these high priority "worst in class"chemicals or lead to their release in the materials' life cycle toward alternatives that we understand to be safer.
At the top of the list are Persistent Bioaccumulative Toxics (PBTs). PBTs do not break down readily from natural processes (persistent), accumulate in fatty tissues concentrating as they move up the food chain (bioaccumulative), and are generally highly toxic in small quantities, creating a toxic legacy that will haunt us for decades to come. Hence environmental health advocates prioritize substitution away from materials whose manufacture, use and disposal result in the release of PBTs into the environment. Persistent Organic Pollutants (POPs) are a priority subset of PBTs targeted by international treaty. Dioxins, furans and PCBS are the prime POPs connected with building materials.
Building materials that release PBT's include polyvinyl chloride (PVC) based products, mercury thermometers, lead solders and roofing materials, and certain paints and finishes.
A large number of chemicals known as VOCs (volatile organic compounds - so called because they volatilize - released from the material as a fume into the air of the building as the material dries or cures) and SVOCs (semi-volatile organic compounds) are also of concern to human health as they affeect the indoor air quality.
For updated information about worst in class chemicals, see HBN/GHSI fact sheet "Toxic Chemicals in Building Materials, an Overview for Health Care Organizations."
Where to Start
Some of the most important materials to avoid in order to reduce the release of persistent bioaccumulative toxic chemicals include: chlorinated building materials, PBT based material treatments, and heavy metal additives or components:
1) Chlorinated building materials: The manufacture and combustion of materials that include chlorine is associated with dioxin and several other POPs. Chlorinated materials to avoid include:
Note that PVC is far and away the largest volume material in this group with neoprene being the only other one in a significant number of products. By phasing out the purchase of PVC building materials, we can greatly reduce the negative impacts of PBT's on environmental health.
While being chlorine-free would be great, the health-based green guidelines like the Green Guide for Health Care (GGHC) sensibly suggests that you go for the high volume materials and don't sweat the minor parts, such as tracks, gaskets, and other seals, as long as a chlorinated compound is not one of the primary materials of the frame or body of the product.
PVC and the other chlorinated plastics are not alone in the use and emission of toxic chemicals in the irmanufacture, use and disposal, but are tarteted due to the chlorine-dioxin connection. All plastics, however - particularly those derived from petrochemicals - have toxics in their lifecycle. "Creating Safe and Healthy Spaces: Selecting Materials that Support Healing" provides an overview of concerns with plastics, including a plastics spectrum that can be used to evaluate many of the plastics commonly used in building materials.
2) PBT based material teatments. Several studies have shown these materials to be accumlating in human tissue at an alarming rate:
3) Heavy metal additives and components. Heavy metals are inherently persistent and often bioaccumulative, including:
Indoor Air Quality In addition to avoiding the PBTs that spread through the environment at large, it is important to avoid materials that contribute to unhealthy indoor air quality:
Preserved wood Efforts to make wood pest resistant has introduced millions of board feet of highly toxic wood into the environment. Avoid chromium copper arsenic (CCA), creosote, and pentachlorophenol treated wood products.
Click here to download a Healthy Building Materials factsheet to help you understand and find healthy building materials (2 page PDF).
For more detailed information about concerns with BFRs, PFCs, heavy metals, indoor air quality, as well as other emerging chemicals of concern, see HBN/GHSI fact sheet “Toxic Chemicals in Building Materials, an Overview for Health Care Organizations.”
Worst in Class Chemicals Resources