subject: New Interior Building Products And Furniture Can Be Analyzed For Potential Impacts On Human Health [print this page] The potential human health impacts of furnishings and building products used indoors can be addressed through chemical testing of these products by a qualified environmental laboratory. One approach is to test representative samples of newly manufactured products in environmental chambers for their air emissions of hazardous volatile organic compounds, or VOCs. These VOCs are present in new products primarily as residual solvents from production of the product and its components. VOC emissions occur by diffusion of chemicals within the solid product to the surface where they are released to air. The amount released depends upon the bulk concentrations of chemicals in the product and their diffusion rates, i.e., processes that occur within the product. Once in air, VOCs impact occupants by inhalation exposure. The magnitude of the exposure is dependent upon the source strength or emission rate, the amount of the product in the building space and the ventilation rate of the space which dilutes and removes the VOCs. The test procedure, known as VOC emission testing, is routinely conducted for many floor products, such as carpet and resilient flooring, and major lines of commercial office furniture.
Concerns regarding the potential health impacts of interior building products and furniture extend beyond VOCs and inhalation as the primary exposure mechanism. For example, many products contain additives such as plasticizers and flame retardants. Organic chemicals in these categories are considered to be semi-volatile, i.e., SVOCs, due to their very low vapor pressures. Phthalate esters are one common family of SVOCs used as plasticizers in some flexible plastics and in products such as PVC flooring. Exposure to phthalates can occur by inhalation and by other routes such as dermal contact and ingestion of contaminated house dust. Some environmental testing programs purport to measure emissions of phthalates using environmental chambers and procedures similar to those employed for VOCs. But, research has shown that the air emissions of phthalates are controlled primarily by parameters external to the product. That is, the chamber environment has a major influence on measured emissions because SVOCs stick to all of the chamber surfaces and equilibrium is only achieved after a month or more of testing. The most credible approach for phthalate testing is to measure the content of these chemicals in interior building products. For phthalate analysis, an environmental laboratory homogenizes and solvent extracts a representative sample of a product. The extract is then analyzed by gas chromatography/mass spectrometry, which allows identification and quantification of the individual chemicals. Potential exposures and exposure pathways in buildings then can be estimated by mechanistic models reported in the scientific literature.
