Are Plasticizers the New Asbestos?
Phthalates in Some ESD Vinyl Tile May Pose Health Risk
Over the last few years, the U.S., Canada and the EU have banned
the use of phthalates, such as DEHP,
di (2-ethylhexyl) phthalate (also known as DOP), in children's toys. These government agencies have now begun to monitor and regulate all use of DEHP/DOP.*
DEHP, found in some ESD vinyl tiles, is a manufactured chemical used to make vinyl soft and flexible. According to the U.S. Agency for Toxicity and Disease Registry (ATSDR), the DEHP in some vinyl products may be as high as 40%. In high concentrations, phthalates such as DEHP/DOP are thought to be toxic to humans, particularly to the liver and testes, and may be carcinogenic.
* The EU lists Di-2-ethylhexyl phthalate (DEHP, DOP) as one of their "Substances of Very High Concern" (SVHC); this ruling requires that the DEHP/DOP content in products exported into the EU be reported. In the United States, DEHP/DOP is included in the priority list of hazardous substances identified by the ATSDR and the EPA.
Under the U.S. Consumer Product Safety Improvement Act (CPSIA), products containing Di-2-ethylhexyl phthalate (DEHP, DOP) have been permanently banned at levels greater than 0.1%: OSHA limits the average concentration of DEHP in workplace air to 5 milligrams of DEHP per cubic meter (mg/m3) of air over an eight-hour workday. The short-term (fifteen minute) exposure limit is 10 mg/m3.
DEHP / DOP Cause for Concern? Maybe.
At low levels, DEHP/DOP is currently believed to pose minimal risk to humans. However, according to the ASTDR, the large surface area-to-volume ratio of vinyl flooring may "allow DEHP to volatilize more readily than it does in other products with smaller surface area-to-volume ratios."
A report on the health hazards of DEHP prepared by a section of the California EPA states that: "Release of the material [DEHP] from plastics containing it into the air are relatively small, but may be important in special circumstances, such as contamination of indoor air. For example, Wams (1987) reported indoor air concentrations of 0.2 to 0.3 mg/m3 in rooms with newly installed floor coverings." This higher concentration of DEHP is due to out-gassing that normally occurs in newly installed vinyl flooring.
The risk is not limited to new vinyl floors. In most cases, ESD vinyl floor tiles are not sealed or waxed, and are maintained using high-speed buffing equipment. The elevated temperatures of the buffing process may also create out-gassing of VOCs and DOP plasticizers.
The Solution: DOP-Free Flooring
Safe solution: Specify DOP-free flooring that will not outgas VOCs and that passes California 1350 indoor air quality testing.
DOP plasticizers are not the only plasticizers capable of enhancing the performance of PVC floor tile. Safer plasticizers can be substituted with no negative effect on performance - and no known health risks. The only advantage DOP seems to offer is its low cost. Factored into a risk-analysis equation, the few cents manufacturers save by using DOP in their industrial flooring products may not be worth the hazard or liability.
Learn more about DEHP / DOP
Articles about DOP, plasticizers and potential health effects.
Agency for Toxic Substances and Disease Registry:
Toxic profile on DEHP / DOP
Overview of plasticizers and their effects on human health and environment
Journal of Environmental Science and Technology:
Predicting Residential Exposure to Phthalate Plasticizer Emitted from Vinyl Flooring: A Mechanistic Analysis
Environmental Protection Agency: