Making Sense of Phthalate-Free Vinyl

Bill Walsh - May 29, 2014

Today my colleagues in HBN’s Pharos Project have released the first comprehensive analysis of the plasticizers that are replacing phthalates in flexible vinyl building products. The replacement chemicals in phthalate-free vinyl are not always clearly identified by manufacturers. The level of toxicity testing and the testing results vary among the six non-phthalate formulas we found now in use. The HBN analysis will help purchasers evaluate the claims of phthalate-free product lines in order to make informed choices about a wide array of materials including flooring, wall guards and coverings, wire and cabling, upholstery and membrane roofing.

PVC (polyvinyl chloride) plastic, also known as vinyl[1], is rigid and brittle in its pure form. Phthalates have long been the chemicals of choice used to achieve the flexibility needed for many uses. Many phthalate plasticizers are known endocrine disrupting chemicals - chemicals that interfere with hormone cell signal pathways – and have been known to have adverse effects on reproduction and development. Additionally, some phthalates are known carcinogens. These additives do not tightly bind to PVC molecules and are known to migrate from vinyl products. Over the past 10 years studies have documented alarming levels of phthalates in infants, children, breast milk, and the general population.[2] Regulation has increased, including bans on some phthalates in some products, and many green building leaders have been deselecting vinyl due in part to the concerns about phthalates.

In response, vinyl manufacturers have introduced phthalate-free products that replace phthalates with other plasticizers. It is important to note that products using recycled vinyl content will continue to contain phthalates, as will most products imported from Asia. For US and European manufactured products, the HBN research finds the following:

  • Two bio-based products, Grindsted SoftnSafe (made by Danisco/DuPont) and Polysorb ID37 (made by Roquette), are well studied and appear to be the least toxic of the six non-phthalate plasticizers reviewed.
  • Petroleum-based compounds sold by Eastman Chemical under the trade names Eastman 168 and Benzoflex, as well as Hexamoll DINCH manufactured by BASF, fare better than phthalates in many but not all health and environmental hazard endpoints. For all petroleum-based plasticizers, except DINCH, further study is needed to address data gaps or uncertainties in conclusions from toxicity testing.
  • The data for Equilibrium by Dow, a bio-based plasticizer, are proprietary, and its GreenScreen evaluation is redacted. Therefore we cannot fully evaluate the hazards for this compound.

The removal of phthalate plasticizers is a good thing. It will reduce human exposure to avoidable chemical hazards. It demonstrates that customers who take a precautionary approach to avoidable chemical hazards can drive positive innovation even in a mature product area such as vinyl. It suggests that had the chemical and plastics industries embraced the precautionary approach, rather than fight it for nearly a decade, we could have accelerated this innovation and reduced avoidable hazards for more people on a faster timeline. Our ability to evaluate many of the replacement plasticizers illustrates the benefits of transparency and disclosure to consumers and manufacturers alike.

But does the removal of phthalate plasticizers render flexible vinyl products equivalent to non-vinyl alternatives? No. The weight of the evidence continues to favor non-vinyl products from an overall environmental and health perspective. More on that topic next week.

Footnotes

[1] Although not all plastics with “vinyl” in the name are PVC. See Sorting out the Vinyls — When is “Vinyl” not PVC?


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