A federal interagency task force has recommended immediate testing by the Environmental Protection Agency of 10 widely used groups of chemicals because they pose a potential threat to human or environmental safety.
The list compiled by the Interagency Testing Committee, an eight-agency organization set up under the 1976 federal Toxic Substances Control Act. includes chemicals found in thousands of products now on the market and others which are handled by millions of production workers, according to government experts.
"These are substances which have a high degree of suspicion of one sort or another plus a high degree of exposure." said William M. Upholt, senior science adviser for EPA's office of toxic substances and a member of the task force.
The task force recommended that teh EPA have the chemical groups tested for a wide variety of potential hazards, including in many cases possible cancer-causing properties, mutagenic effects and the potential that some of the suspect chemicals may cause embryonic malformations in women exposed to them.
According to the task force report, which has not yet been released but which was made available to The Washington Post, each of the substances has shown some indication of the hazards in preliminary testing. Members of the group interviewed yesterday said additional tests were needed to determine just how dangerous the chemicals actually are.
The 10 chemicals and chemical groups on the suspect list are: alkyl epoxides, alkyl phthalates, chlorinated benzenes mono- and di-, chlorinated paraffins, chloromethane, cresols, hexachloro-1.3-butadiene, nitrobenzene, toluene and xylenes.
Task force members said it is likely that additional chemical groupings will be put on the list, which was submitted to EPA Administrator Douglas M. Costle. The task force is working its way through a list of 330 chemical substances it singled out for study in July. Federal officials have estimated that there are between 50,000 and 60,000 chemicals and chemical compounds which have been produced, most of which have not been tested for safety.
"There are some that we are reviewing now that may turn out to be even worse than the ones we have already submitted." said Dr. Jean G. French, a task force member and research official at the National Institute for Occupational Safety and Health.
The list of chemicals submitted by the task force to the EPA does not include chemicals which are used in drugs, pesticides or food additives. Those chemicals are the subject of separate EPA or Food and Drug Administration studies.
However, the 10 chemical groups that have been turned over to the regulatory agency cover a vast area of human and environmental exposure, according to the report. Much of the use of the chemicals occurs during intermediate manufacturing processes, the report said.
For example, one chemical compound called toluene, which has an annual production figure in excess of 5 billion pounds, is widely used in industry as a solvent to break down other chemicals. More than 1 million workers are exposed to toluene, which the report states has been shown to have a "carcinogenic potential" in tests on laboratory animals.
Chlorinated paraffins, another chemical group on the list, are widely sold commercially in paraffin oils or waves as well as in a number of paints and household products, according to the report. About 80 million pounds of the chemicals are produced annually, and limited laboratory tests have shown they have caused degenerative changes in the livers and spleens of mice.
Members of the task force said yesterday they had difficulty in some cases in obtaining data because manufacturers were reluctant to turn over production information or lists of which products contained the suspect chemicals.
Steven Jelinek, acting administrator for toxic substances at EPA, said that under the federal law Costle would have one year in which to make a final decision on which chemicals should be tested. Testing, which is done by manufacturers for EPA, is the next step in the regulatory process which could result in removal of a product from the market, EPA officials said.
Jelinek said a chemical's presence on the task force list indicated "the possibility that there is a problem." He said not all the chemicals on the list may turn out to be hazardous. In some cases, he said, only one or several chemicals from a large grouping included on the list may be harmful.
"The importance here is that this is the first formal priority list to come out of the toxic substances act," said Jelinek. "It isn't enough to go forth with the regulatory process but it does give us a good basis from which to work."