As many as five million hand-held electric hair dryers emit potentially dangerous levels of cancer-causing asbestos particles, government regulators confirmed yesterday.

Officials of the Consumer Product Safety Commission said they have hastened efforts to determine which hair dryers now on the market are dangerous. Their action followed an investigative report on hair dryers on WRC-TV (Channel 4).

In an uninterrupted 15-minute report, WRC's investigative team summarized the results of a nine-month probe in which independent laboratories found asbestos linings in 24 of 112 new and used hair dryers.

Tht asbestos lining is used to keep the dryer from overheating or melting. But according to appaliance industry officials, several alternative products can be used. Asbestos has been found by the Department of Health, Education and Welfare to be responsible for as many as 75,000 cancer deaths every year.

WRC claimed it had first contacted the Consumer Product Safety Commission about the hair dryer problem nine months ago, but said the agency had done its own study, which determined hair dryers were not a serious problem.

Last December, the television station gave a Norelco hair dryer to the CPSC and asked that it be tested for asbestos. The agency confirmed the asbestos content, but said more sophisticated analysis would have to be done to determine the level of danger, and the agency did not have the equipment to do such an investigation.

Late last week, the WRC investigators returned to the CPSC with the more sophisticated results of tests they had commissioned using an electron microscope. At that point, CPSC Chairman Susan King reversed an earlier commission position and ordered a hair dryer investigation on a "high-priority basis."

"We had a consultants' report delivered to us in April 1978 which identified 75-100 consumer products containing asbestos," King said in an interview last night. "Based on the conclusions of that study, we were more concerned about our products and concentrated our limited resources on investigating those products."

But WRC found that hair dryers should have been classified a higher-priority item. reporters Jack Cloherty and Lee Thompson alleged.

The reporters found that 25 million hair dryers are in use in the U.S., and that they are particularly dangerous because they are used in close proximity to the face. As the appliances deteriorate through use, particles of a asbestos flake off from the linings.

An Environmental Defense Fund spokesman said the asbestos level of the hair dryers was at least as dangerous as the level found in certain schools recently.

"We can now justify emergency procedures," CPSC's King said last night. "Before, we just didn't have the hard data to move."

CPSC sources said the consultant who did the original report, Kearney Associates, no longer does work for the CPSC because the agency had been dissatisified with the firm's work.

King said she was moving as quickly as possible to free up funding for this project. "We will find the money. We will take the money from other projects. We will readjust our budget," she said.

Some of the hairdryers the WRC reporters said could be affected were Sears, J.C. Penney, Norelco and Montgomery Ward brands.