Repainting the PCB Picture

This is an open letter to the authors of the article, "Painting the PCB Picture."

I am writing in response to Mr. David M. Bloom and Mr. Steven B. Gold's "Painting the PCB Picture" article, which was published in the October, 2000, issue of Environmental Protection. (See under Archives), and to Mr. Bloom and Gold's November 24, 2000, letter to Monsanto Company posing questions concerning polychlorinated biphenyls (PCBs) in general and the use of PCBs in paints in particular. Solutia Inc. was created on September 1, 1997, as a spin-off of Monsanto and comprises the former chemical businesses of Monsanto. Since the spin-off, Solutia rather than Monsanto has responded to inquiries such as yours regarding PCBs. I am writing this letter in my capacity as Director, Environmental Affairs for Solutia.

Before responding to the specific questions in your letter, I would like to address several inaccuracies in your article. It refers to the 1968 incident in Japan in which approximately 1,200 persons were affected by ingestion of rice oil which had been inadvertently contaminated by thermally degraded heat transfer fluid during the manufacturing process. (The incident is referred to as "Yusho", which is Japanese for "rice oil disease".) Although early reports suggested that PCBs were the causative agent, subsequent investigations confirmed that the most toxicologically significant contaminants in the cooking oil were polychlorinated dibenzofurans ("PCDFs"), not polychlorinated biphenyls. (See, for example, the Toxicological Profile for Polychlorinated Biphenyls Update, which was published by the Agency for Toxic Substances and Disease Registry (ATSDR), in September of 1997. On page 13, that document states, "There is a historical linkage between Yusho and PCBs, but effects from these incidents are not reviewed in this profile because CDFs appear to be the main causal agent".)

Your article further states that "soon" after the 1968 Yusho incident, "studies revealed that PCBs could cause cancer in humans." Although PCBs at high doses have been shown to cause liver cancer in laboratory rodents, there is no consistent, convincing evidence that PCBs are associated with elevated risks for humans in relatively highly exposed occupational populations. Based on these human epidemiological studies, which only began to appear in the early 1980s, there is no reason for concern that exposures to environmental levels of PCBs pose real risks of cancer in humans. In fact, the most recent and largest study to date of persons occupationally exposed to PCBs concluded, "The lack of any significant elevations in the site-specific cancer mortality of the production workers adds important information about human health effects of PCBs". And summarizing their review of the literature, the authors state, "The lack of consistent findings with respect to occupational PCB exposure and mortality in studies conducted to date would suggest a lack of an association". ("Mortality in Male and Female Capacitor Workers Exposed to Polychlorinated Biphenyls", Kimbrough, R. D., et al., Journal of Occupational and Environmental Medicine, 1999, Volume 41 (No. 3), pp. 161-171.)

The statement in "Painting the PCB Picture" that "the carcinogenic characteristics of PCBs led to the ban on manufacturing PCBs in the United States beginning in 1978" is also inaccurate. Environmental concerns, not the potential for adverse human health effects, were the primary reason that PCBs were targeted for regulation under Toxic Substances Control Act (TSCA). Also, the ban on the manufacture of PCBs in the United States imposed by regulations promulgated under TSCA became effective in July of 1979, not in 1978 as your article states. The subsequent statement in your article under the heading "Laws currently in place" indicating that "the manufacturing of paints using PCBs was banned in 1978" is also inaccurate because the TSCA regulations banning the use of PCBs in other than a totally-enclosed fashion did not become effective until July of 1979. Your readers should know that Monsanto voluntarily acted far in advance of any regulations concerning the manufacture and use of PCBs. By 1972, Monsanto had restricted sales of PCBs to totally enclosed uses, essentially limiting sales to manufacturers of electrical equipment. The markets into which PCBs were no longer sold included the plasticizer markets, where PCBs had been distributed for uses such as plasticizers in paints. In 1977, Monsanto voluntarily ceased all manufacture of PCBs, two years in advance of the 1979 regulations.

"Painting the PCB Picture" exaggerates the extent of the use of PCBs in paints by stating that "by the 1950s, PCBs had become an established part of many exterior and interior paints and other coating formulations." This statement is incorrect, particularly as it pertains to interior paints. To the best of Solutia's knowledge, PCBs were not used in interior or residential decorative paints in the United States. Instead, PCBs were used in specialty paints (including, as your article notes, chlorinated rubber paints) usually intended for industrial and/or military applications. It is therefore highly unlikely that a demolition or construction crew working on a residential project would encounter PCBs in paints.

Your article notes the potential for "furans" to be formed upon the thermal oxidation of PCBs. "Furans" is a general term; the particular furans that potentially can be formed when PCBs (and many other chlorinated materials) are burned under certain conditions are polychlorinated dibenzofurans (PCDFs), which are the thermal degradation products implicated in the Yusho incident. Although PCDFs can be formed by the thermal degradation of PCBs under certain very specific conditions including temperature and oxygen concentration, it should be noted that PCDFs are common byproducts of many combustion processes, and their presence is not uniquely associated with the presence of PCBs.

"Painting the PCB Picture" notes the existence of the TSCA regulations contained in 40 C.F.R. Part 761.62, which govern the disposal of "PCB bulk product waste" (which includes dried paints), but it fails to discuss pending rulemaking for TSCA regulations that would authorize continued use of various non-liquid PCBs, including PCBs in dried paints, subject to substantial conditions. This rulemaking would have some impact on the concerns noted in your article because it would impose conditions designed to minimize human exposure on the continued use of solids, including dried paints, known to contain PCBs. Currently, there is no use authorization in the TSCA regulations for PCBs in place in dried paints and many other non-liquid forms. The comment period on a proposed rule (40 C.F.R. Part 761.30(q)) that would authorize the continued use of PCBs in existing dried paint and other non-liquid PCB forms subject to significant conditions was extended on April 6, 2000, until January 10, 2001. (See 65 Fed. Reg. 18018-18020.)

The proposed 40 C.F.R. Part 761.30(q) authorizing the conditional continued use of many non-liquid PCBs was first proposed by EPA on December 6, 1994, along with many other provisions that were subsequently incorporated into the June 29, 1998, PCB "Mega Rule". (See 59 Fed. Reg. 62788-62874.) When EPA finalized the Mega Rule in June of 1998, however, it deferred action on Part 761.30(q) "for future rulemaking" because "EPA needed additional time to review the recently submitted risk assessment studies and also to obtain additional data for certain uses in order to reduce the uncertainties associated with the available studies." (See 63 Fed. Reg. 35384, 35386.) The proposed conditions under which the continued use of non-liquid PCBs would be authorized are strict and include quarterly or annual air monitoring, quarterly or annual surface sampling, encapsulation, marking, notification of EPA, provision of information to potentially exposed individuals, and recordkeeping. The conditions diminish to marking and providing information if the material is shown to leach at less than 50 parts per billion using the TCLP (EPA's toxicity characteristic leachate procedure).

The proposed Part 761.30(q) would apply to certain non-liquid PCB materials that were in use before July 2, 1979, and that were manufactured to contain PCBs (as opposed to materials inadvertently contaminated through spills of PCBs). An independent provision (40 C.F.R. Part 761.30(p)) that was included in the Mega Rule already conditionally authorizes the use of porous surfaces such as concrete that are contaminated with PCBs via inadvertent spills. Although we do not know at this time precisely what conditions Part 761.30(q) will impose when EPA ultimately promulgates it as a final rule, it probably will ameliorate some of the concerns that you note in your article. Part 761.30(q) will therefore address what you refer to as the "inconsistent legal framework between lead and asbestos on one side and PCBs on the other."

With respect to the questions you posed in your November 24, 2000, letter, it is difficult to answer such historical manufacturing and marketing questions concerning PCBs because the pertinent events occurred decades ago. Monsanto began manufacturing PCBs in 1935 when it acquired Swann Chemical Company, which had been manufacturing PCBs since about 1929. PCBs were primarily used as a fire-resistant safety fluid for electrical applications, but over the years they were adopted for a variety of additional applications, including the general category of applications known as "plasticizer" applications. The use of PCBs in paints was a plasticizer application. As noted above, however, Solutia is not aware of the use of PCBs in paint formulations for residential or interior decorative use. Instead, PCBs were a component of specialty paints designed for other applications that were primarily of an industrial nature. The PCBs used for plasticizer applications, including those used in paints, were often sold to ind ependent distributors who resold them to the manufacturers of the ultimate product. Therefore, Monsanto is unable to furnish information concerning customers, product names, or volumes as you requested.

As environmental concerns over PCBs began to emerge in the late 1960s and early 1970s, Monsanto voluntarily terminated sales of PCBs for plasticizer applications effective August 31, 1970. Although paint manufacturers could have legally manufactured PCB-containing paint until July of 1979, when the TSCA regulations restricting the use of PCBs became effective, it is not likely that PCB-containing paints were manufactured in the United States after the early 1970s. As mentioned above, Monsanto voluntarily ceased manufacturing PCBs altogether in 1977, two years before the EPA implemented regulations banning their manufacture.

I hope the information provided in this letter is useful to you and your readers. If you have additional questions, please feel free to contact me.

Robert G. Kaley, II, PhD, Director, Environmental Affairs, Solutia Inc.

The Authors' Response

We appreciate the numerous positive responses, and are gratified our goal was accomplished: the issue of PCBs in Paint has been brought into the forefront of discussions among environmental professionals. Many were unaware that PCBs exist in some paints.

Along with the many positive responses, we have also received many questions from other professionals, focusing on the extent of the problem (e.g., quantities, frequency applied, specific products). While the goal of our article was not to provide a treatise on this issue, we hope our efforts will result in environmental professionals continuing the dialogue, exploring the extent of PCBs in paint.

We are aware that predominant use of PCBs was oils in transformers and other closed systems. We are also aware that ASTM and other standard practice in our industry include the investigation of possible environmental releases from such equipment. However, we believe that gradual deterioration of PCB-containing paint or its ignorant disposal could be a major contributor to PCBs in the environment.

Contrary to some comments, our research suggests that paint was not "contaminated" with PCBs, but rather added to paint during manufacture to give chlorinated rubber paint its desired properties of low permeability and high chemical resistence. When these paints were manufactured, such an additive would have been as legal as other paint additives (e.g., lead or asbestos).

In response to several requests, we have attempted to obtain information concerning customers, specific product names, and quantities sold. References cited in our article state common applications included swimming pools, highway striping, floor paints, and paints for brickwork, concrete, asbestos, and steelwork. This month, we received a response from Dr. Bob Kaley, Environmental Affairs Director at Solutia Corporation. The chemical businesses of Monsanto, formerly the major PCB manufacturer, were spun-off as Solutia. Dr. Kaley confirmed that PCBs were sold to independent chemical distributors, who resold them to paint manufacturers. Unfortunately, Dr. Kaley was "unable to furnish information concerning customers, product names, or volumes as we requested . . . because the pertinent events occurred decades ago."

Many also question the carcinogenicity of PCBs. Research continues as to the carcinogenicity of many substances, including PCBs. In a January 2001 report, the Public Health Service National Toxicology Program concluded that PCBs are reasonably anticipated to be a human carcinogen, but that inadequate studies of PCB-exposed human populations exist to verify that PCBs are a human carcinogen.

Our article does not suggest that testing for PCBs in paint be routinely performed for all environmental site assessments. Rather, our goal was -- and remains -- to make our community of environmental professionals aware that the potential exists for paint to contain significant levels of PCBs, and to protect our clients from the consequences of not knowing about that potential. Lack of knowledge in our profession is costly to ourselves, our clients, and the public at large.

We welcome additional information on PCB contamination, and the source of that contamination. With this information, we can all use our best professional judgment in determining the extent of the problem, and what action, if any, should be taken.

Steven B. Gold and David M. Bloom, February 10, 2001

Authors of "Painting the PCB Picture" which appeared in Environmental Protection, Volume 11, Number 10, October 2000, Page 58.

This article appeared in the April 2001 issue of Environmental Protection, Vol. 12, No. 4, on page 58.

This article originally appeared in the 04/01/2001 issue of Environmental Protection.

About the Author

Ray H. Ankers is vice president of EH&S at Novartis Corp. US, Summit, N.J.

comments powered by Disqus