Perfluorinated Compounds Persist, As Do Concerns About Their Safety

In February 2017, Dupont and Chemours, a DuPont spin-off, settled over 3,000 pending lawsuits brought by Ohio and West Virginia residents who claimed they were sickened by contaminated drinking water[1]. The lawsuits had grown from a 1999 suit that claimed perfluorooctanoic acid (PFOA), a chemical ingredient in numerous consumer products including Teflon, seeped into the Ohio River from Dupont’s Washington Works plant. PFOA has been profiled in CoMeta™ since its inception, with PFOA’s profile demonstrating steadily growing scientific consensus around PFOA’s ability to cause bodily injury.

Before this year’s settlement, Dupont and other chemical companies voluntarily phased out production of several of the most commonly used perfluorinated chemicals (PFCs), with PFOA and perfluorooctanesulfonic acid (PFOS) receiving the most attention. Both PFOA and PFOS are also known as C8 perfluorinated compounds, with C8 representing the number of carbon atoms in their chemical formula chain structure. PFCs can have chain structures ranging from four to twenty-four carbons (C4-C24) in length.

Despite the phase out, human exposures to PFCs remain because PFOA and PFOS were largely substituted for other PFCs that had longer or shorter carbon chains.  Additionally, many PFCs are environmentally persistent with nearly decade-long half-lives[2].

Consumers and manufacturers appear uncertain about the safety of PFOA and PFOS substitutes. For example, in early 2016, Tyco, a company that manufactures fire protection products, announced it was reformulating its firefighting foams to eliminate C8 perfluorinated compounds and to replace them with C6 perfluorinated compounds[3]. Tyco states that the change is meant to be “environmentally mindful.” But only a few months earlier, Levi Strauss & Co., an American clothing manufacturer, announced it was no longer going to use C6 perfluorinated compounds due to concerns about toxicity and environmental contamination[4].

Praedicat is adding several new PFC Litagion® agents to CoMeta in the March 2017 release including perfluorohexanoic acid (PFHxA) and Perfluorohexane sulfonate (PFHxS). These are both C6 perfluorinated compounds and two of the most prominent PFOA and PFOS replacements, respectively. Though many of these new PFC Litagion agents have thin scientific literatures and, hence, low GC risk scores, their inclusion is important in order to understand the potential emerging risks and the possible similarities to PFOA and PFOS. Additional PFCs are forthcoming in future CoMeta releases along with updated company Dartboard visualizations.