Ralph Nader's health researchers yesterday petitioned for an immediate sharp reduction in worker exposure to chloroform, a chemical which, they charge, "presents an immediate grave danger of cancer to an estimated 40,000 workers."

The petition from Public Citizen's Health Research Group and the Chicago Area Committe on Occupational Safety and Health to Eula Bingham, assistant secretary of labor for occupational safety and health, asks for an emergency temporary standard that in most cases would forbid occupational exposure. It would require companies to obtain a permit befire using chloroform, and then only in a close-off area.

Chloroform is now mainly used in making fluorocarbon aerosol psopellants. The government recently announced plans to phase out those propellants over a twoyear period to protect the earth's ozone layer, which filters out cancercausing radiation from the sun.

Chloroform is also converted into chemicals used in refrigerants, and is used in the production of paints, plastics, biological drugs and laboratory products. Last year, following a Health Research Group lawsuit, the Food and Drug Administration banned the use of chloroform in cosmetics and drugs. (It was commonly used in cough medicines, toothpaste, liniments, salves and hair tints.)

This action followed a National Cancer Institute (NCI) study showing that chloroform caused liver and kidney tumors when fed to rats and mice.

The NCI study showed that acute exposure to levels of chloroform - approximately equal to the current work place maximum - induced liver poisoning in mice, and that nearly all mice fed larger doses developed liver cancer.

Workers inhale chloroform rather than ingesting it, but the Health Research Group said government scientists believe that "ingestion and inhalation effects on the kidney and liver."

Chloroform at one time was used as an anesthetic, but rarely is any longer.

A year ago, the National Institute for Occupational Safety and Health (NOISH), recommended that exposure to chloroform in the workplace be drastically reduced.

Bingham said she shared the concern of the Health Research Group and that she was "going to take appropriate action as rapidly as possible." The quickest route is a temporary emergency order putting new standards into effect immdeiately, pending hearings on a permanent regulation.