The U.S. National Toxicology Program published its 500th two-year safety test of chemicals in rodents a landmark in a series that has influenced what is allowed in your drugs, your water, your foods, and your air, for these reports have often formed the foundation for regulatory action by the Food and Drug Administration, Environmental Protection Agency, Occupational Safety and Health Administration, and Consumer Product Safety Commission.

The 500th report is on ordinary naphthalene, the principle ingredient in mothballs and the familiar odor in millions of closets filled with winter's woolens. It is also used as a restroom deodorizer.

The rat study found clear evidence that naphthalene causes cancer, a finding that scientists and regulators must wrestle with to determine if, as commonly used, it presents a risk to humans as well. An abstract of the study is available on request or at the web site listed below.

The National Toxicology Program is headquartered at the National Institute of Environmental Health Sciences. NIEHS/NTP Director Kenneth Olden, Ph.D., said, "We are proud of this milestone of health protection. These 500 tests have had a profound effect on our health and the length of our lives. In 1997 and 1998 alone, nine of these studies were the basis for regulatory decisions by the EPA, FDA, and Occupational Safety and Health Administration."

Dr. Olden added, "The National Toxicology Program's testing prevents disease by identifying hazards and allowing the regulatory agencies and the marketplace to act on these results. That is how NTP has its great benefit on human health."

Since NTP was established in 1978, its reports have changed how substances are handled in occupational and home settings, and in the more general environment. Some examples of chemicals that have been found to cause tumors in laboratory animals and have subsequently been regulated or dropped from use, are:

*Tetrachlor
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Contact: Tom Hawkins
hawkins@niehs.nih.gov
919-541-1402
NIH/National Institute of Environmental Health Sciences
24-Jan-2001