Global Effort on PBT Chemicals Called Useful; Funding Seen as Challenge

By Pat Rizzuto

Jan. 21 --Governments could reduce redundant work and encourage more consistent classifications of persistent, bioaccumulative and toxic (PBTs) chemicals by sharing data and approaches they use to determine how and when to classify a chemical as a PBT, governmental and academic science policy analysts said Jan. 17.

Yet, shrinking budgets combined with the growing number of chemical laws, regulations and related issues that countries and regions already are tackling on their own and through international treaties and other forums make it a challenge to find and fund government scientists' participation, they said.

The science policy specialists discussed PBT chemicals in light of a report, Scientific and Policy Analysis of Persistent, Bioaccumulative and Toxic Chemicals: A Comparison of Practices in Asia, Europe and North America, released by Indiana University in December.

The university organized a meeting, PBTs: Science and Policy, and invited 10 speakers to comment on the findings and recommendations in its report.

One conclusion of the PBT report was that greater harmonization in data gathering and PBT assessments would help smooth trade and avoid duplication of effort.

The American Chemistry Council funded the report. Its international team of authors includes John Graham, dean of Indiana University's School of Public and Environmental Affairs, who served as the administrator of the Office of Management and Budget's Office of Information and Regulatory Affairs from 2001 to 2006; Cornelis “Kees” van Leeuwen, principal scientist at KWR Watercycle Research Institute in Utrecht, Netherlands; Marco Vighi, an applied ecology professor at the University of Milano-Bicocca, in Milan, Italy; and Anna Gergely, a chemist who directs the environmental, health and safety regulatory division of Steptoe & Johnson LLP's Brussels office.

Useful Compilation

The classification of chemicals as PBTs is playing an increasingly prominent role in local, national, regional and international chemicals policy, the report noted. The reasons are the intrinsic characteristics of these chemicals: their ability to remain in the environment without degrading, their ability to accumulate in organisms and be concentrated within the food chain and various harms they may cause people or the environment.

Gunter Hormandinger, environment counselor at the EU delegation to the United States in Washington, D.C., said the PBT report was highly welcomed by European Commission and long overdue.

Maria Doa, director of the U.S. Environmental Protection Agency's Chemical Control Division, also said EPA found the report to be a useful compilation of current practices.

More PBTs Than Anticipated

Among the report's findings:

• “While it was originally thought that the number of PBTs in commerce was fairly small (perhaps less than twenty), recent screening exercises of chemical inventories suggest that the number of PBTs in commerce is probably between 100 and 1,000 depending on the particular data and cut-off values that are used. This number is small relative to the total number of chemicals in commerce but large enough to put substantial work burdens on regulatory agencies and industry;”

• “The estimated number of PBTs in commercial use is sensitive to the cut-off values employed and the specific tests and models used for PBT determination. When modeling data are replaced by appropriate measurements, the estimated number of PBTs tends to decline significantly;”

• Governments increasingly are using weight-of-evidence approaches to classify PBTs, but “little guidance exists on how weight of evidence judgments about P and B should be made on a case-by-case basis. As a result, PBT determinations may become, to varying degrees, subjective, unpredictable, inconsistent, and not fully replicable;” and

• “Some jurisdictions go beyond PBT determinations and identify as possible concerns chemicals that might be called 'partial PBTs,' which typically means that only two of the three properties have been established.”

Nearly Two Dozen Recommendations

Among nearly two dozen recommendations, the report suggested:

• “To avoid duplication of effort and foster predictability in global trade, greater efforts at international harmonization are needed in data gathering and assessment, especially in the cut-off values for P, B, and T,” including the importance, or “weight,” assessors give to each of those three values;

• “Chemicals found to be 'partial PBTs' should not be given formal designations because the number of chemicals with all three PBT properties will be high enough for the foreseeable future to stretch the resources of regulators and industry;”

• Governments and industry should invest more resources in research to generate physical chemical characteristic, toxicity and exposure data; and

• “[M[]ore focus should be given to using PBT determination as a priority-setting tool for risk assessment and management rather than as a trigger for binding risk-management obligations.”

'Retail Regulation' Will Continue

One speaker, Daniel Rosenberg, a senior attorney with the Natural Resources Defense Council, told Bloomberg BNA he found the PBT report conventional and disappointing.

“Perhaps predictably, since it was funded by the chemical industry, it offers no ideas for quick action to protect the public from even the worst PBTs, or any other chemicals of concern. The result is more of the same--less opportunity for public engagement and more delay for protections decades overdue,” he said.

During his presentation, Rosenberg said “retail regulation,” in which major retailers or product manufacturers refuse to carry products made with certain chemicals, is going to continue.

Chemical manufacturers can continue to fight allegations that a chemical causes problems, or they can get in front of the issue and agree on some number--25, 50, 100--of chemicals that pose concerns due to PBT or other characteristics, he said.

Chemical manufacturers would gain credibility if their trade associations were to identify a selection of chemicals, and companies worked to develop alternative to the problematic compounds, he said.

Limited Resources, Competing Demands

Bette Meek, a toxicologist who worked on global chemical risk assessment issues for years at Health Canada before retiring to teach at the University of Ottawa, told Bloomberg BNA she fully supports global efforts to jointly work on PBTs.

She asked, however, who would support the international forums suggested by the report or the international meetings it suggests some organization host.

A problem, Meek told the audience, is that government agencies in many countries are facing shrinking budgets and increased demands on their staff.

It is hard to find enough staff to participate in the many global chemical meetings taking place, Meek said.

Another practical problem is that it takes time--10 years or more--to phase a chemical out of commerce, said Mark Greenwood of Greenwood Environmental Counsel, who has served in several senior EPA positions, including as associate general counsel for pesticides and toxic substances.

PBTs are among the types of chemicals being placed into a growing number of chemicals-of-concern lists around the world, according to Indiana University's report.

It is unrealistic to think that the hundreds of PBTs the report says are in commerce could be phased out in 10 or even 20 years, he said. “That is not going to happen.”

Special Properties, Exposures

Some speakers and some audience members said the idea of working together to share information about PBTs and jointly develop ways to classify and address them has merit, but classification decisions cannot be formulaic.

Some chemicals may have PBT characteristics, but also have properties that make those characteristics hard to identify in standard tests, Doa said.

For example, a chemical may not be water-soluble in the time or conditions an approved protocol uses. Yet longer testing times, the organisms in sediments and other factors could create the conditions for the chemical's PBT properties to manifest.

Many standard tests for persistence assume a chemical will be exposed to sunlight, yet chemicals in household dust are less exposed to sunlight and may last longer, one speaker said.

To contact the reporter on this story: Pat Rizzuto in Washington at

To contact the editor responsible for this story: Larry Pearl at

Information about Indiana University's report, “Scientific and Policy Analysis of Persistent, Bioaccumulative and Toxic Chemicals: A Comparison of Practices in Asia, Europe and North America,” and a link to the document are available at