By-product PCBs have become a matter of concern to state governments working to meet water quality and fish consumption standards for PCBs, some of which are far more stringent than those set by the EPA. For example, as noted above, the Spokane Tribe’s water quality standards for PCBs based on fish consumption in Washington are more than 95% lower than those set by the EPA. The federal government has set this limit at 170 ppq, but the Spokane Tribe set a standard of 3.37 ppq, reflecting that local population’s high fish consumption.12Although state and local governments have been working to address legacy PCB issues, the nonlegacy PCB issue has emerged as paper recycling has increased nationwide and begun to be recognized as an ongoing PCB source. At its 2012 summer meeting, the Environmental Council of the States (ECOS), an association of state environmental agency leaders, passed a resolution calling on the EPA to work with industry and states to develop cleaner pigment and ink manufacturing processes and products.27
As illustrated by the case of the IEP recycling facility—which has no chlorinated waste sources apart from the paper it recycles—the amounts of PCBs allowable in printing ink pigments may make it impossible for facilities to meet local water quality standards for PCBs, even with state-of-the-art water treatment.4,12,28,29 As long as IEP continues to take in paper printed with PCB-containing inks, these compounds will remain in its waste stream. ECOS would like to see these contaminants controlled upstream at the product and process source rather than making this the full responsibility of facilities at the downstream end of the product life cycle.
This is an issue of which EPA is well aware. In April 2010 the agency published an advanced notice that it intends to reassess its PCB regulations.30 Among its proposals is a revision of the current definition of an “excluded manufacturing process” that permits certain by-product PCBs up to 50 ppm. The proposed revised rule would eliminate the limit on the allowed annual average concentration of PCBs and reduce the maximum PCB concentration allowed in manufactured or imported products to less than 1 ppm. This overall rulemaking process began in 2009 and is currently not projected to be completed until 2014. When asked in December 2012 for details on its status an EPA spokesperson would not provide any details, but said the agency is “still considering comments and working on the rule.”
In a 2010 letter to the EPA submitted as part of the rulemaking docket, the Color Pigments Manufacturing Association (CPMA), a trade association representing companies in the United States, Canada, and Mexico, stated that the manufacturing processes involved in making diarylide, phthalocyanine, and certain monazo pigments would be negatively impacted if by-product PCBs were disallowed from these products. CPMA said it is not technically feasible to alter manufacturing processes to eliminate by-product PCBs or to reduce them to the proposed 1-ppm level, nor is testing to such a level feasible.31
The industry association also said that taking these pigments off the market would jeopardize most color printing, the vast majority of yellow, blue, and green paint as well as many plastic formulations, and a large number of red pigments used primarily in paints, plastics, and specialized inks.31 Furthermore, the association claimed, compliance with the proposed 1-ppm level would put the U.S. industry at a competitive disadvantage internationally—a comment the EPA has noted in responses to inquiries about the rulemaking.32,33
Neither CPMA nor any companies that use pigments in inks, dyes, or paints contacted for this story would discuss manufacturing processes directly or provide details of why changing current processes is so challenging. However, John Warner, president and chief technology officer of the Warner Babcock Institute for Green Chemistry in Wilmington, Massachusetts, who holds more than 30 chemical patents, explains that to be commercially successful, a pigment has to be persistent. It has to be stable in light and, depending on the application, also stable in water. Also depending on the application, the pigment may have to be compatible with adhesives or have adhesive properties itself. This, says Warner, explains why come commercial pigments are manufactured with processes that would also produce environmentally persistent by-products.
In its comments to the EPA, CPMA also said that pigments that contain PCB by-products are not toxic or bioaccumulative.31 In a January 2011 position paper on this issue, the Ecological and Toxicological Association of Dyes and Organic Pigment Manufacturers (ETAD), a trade association based in Switzerland, wrote that trace levels of by-product PCBs in pigments do not pose a human health hazard. ETAD said pigments are incorporated into products in such a way that environmental or human exposure to these PCBs is unlikely to occur and that release of any PCBs is “improbable—until both polymeric matrix and the pigments degrade.” ETAD further stated that PCBs in wastewater would likely be captured by filtration, although it does not have any data to support that speculation. It also said in the same document that there is no information to link PCB 11 with pigments.34
Asked to comment on these assertions, Robertson says that PCBs “do not degrade even if the matrices in which they may be applied do.” He also noted that PCBs can be released from dyes and pigments and become a major concern in city wastewater, as the Rodenburg research shows. To say that PCBs “are trapped and do not leave the matrix, that is clearly false,” he says.
As part of its comments to the EPA on the proposed revision of allowable by-product PCB levels, CPMA submitted a 1987 study conducted by researchers affiliated with ETAD and chemical manufacturer Ciba-Geigy, which had a long history of dye manufacturing. The study, which looked at the relative solubility in water and octanol of various organic dyes, concluded that since organic pigments are not readily soluble in these media and are of large molecular size, they are unlikely to be taken up by fish and therefore do not have to be assessed for bioaccumulation in fish.35 But Robertson points out that the dyes tested in the study have many functional chemical groups that allow for degradation by microbes and other organisms. This, he says, may mean that once in an aquatic environment, breakdown products might predominate. He also notes that PCBs do not readily biodegrade in water, so if they are present in pigments or dyes released to water, they might persist after the rest of the compound breaks down.
Also important to understanding by-product PCBs’ presence in the environment is the fact that different environmental monitoring and testing methods will detect different PCB congeners. Some methods are more sensitive than others and are designed to more precisely detect and identify individual PCB congeners.36 According to IEP environmental manager Krapas, the test methods approved by the EPA for regulatory purposes are not the most sophisticated available. What this means is that if testing is done using only the PCB monitoring tests currently used to meet EPA regulatory requirements, some congeners—including those in products such as inks and pigments—could remain undetected.