The Occupational Safety and Health Administration has proposed revoking 194 safety and health standards that it says are unenforceable the way they are written. But the move has concerned some representatives of organized labor, who say that the agency should simply rewrite the regulations, not eliminate them.

The provisions all use the word "should" rather than "shall." In legal terms, "shall" is considered mandatory and "should" only advisory.

In the past, OSHA has insisted that all its standards were mandatory, regardless of which word was used. But companies repeatedly have challenged that position, and, according to OSHA officials, most appellate courts have sided with the employers.

In a notice published Friday in the Federal Register, OSHA cited as its evidence a 1978 decision in which the 3rd U.S. Circuit Court of Appeals sided with the Pittsburgh-Des Moines Steel Co. and said standards containing the word "should" were not mandatory.

George E. Smith, director of safety for the International Brotherhood of Electrical Workers, said he understands the legal problems involving "should." But he said he thought OSHA was going to resolve the issue by changing all the "shoulds" to "shall."

"Eliminating the permissible word and eliminating the provision are two different things. I find it disturbing," said Smith.

But OSHA claims that changing "should" to "shall" would create further legal problems because the regulations were originally written as voluntary standards.

The confusion dates from the early 1970s, when OSHA relied heavily on standards developed by the American National Standards Institute and the National Fire Protection Association in writing its original standards. The ANSI standards, in particular, are normally intended to be advisory and so frequently use the word "should." In many cases, OSHA adopted the ANSI standards verbatim.

OSHA officials said they would propose new rules, where necessary, to replace some of the revoked standards. In its Federal Register notice, the agency said that, for instance, the standard for nonionizing radiation "covers a hazard which OSHA considers to be worthy of consideration for future regulatory action."

However, an OSHA spokesman said the agency has "not made any definite decision about" which items should be covered by new rules nor how long the process would take. "We are waiting to evaluate" comments on the proposals before deciding how to proceed, she said.

If the standard that was revoked covered a hazard that might cause death or serious harm to an employe, OSHA said it would be able to issue "general duty clause" citations to prevent dangerous situations. (These citations are issued when there are no specific rules that apply to a hazardous situation.)

OSHA also said that even though the "should" standards could not be enforced, the agency could not issue "general duty" citations of violations in those areas as long as the standards were in place.

Among the provisions the proposal would eliminate is one stating that if work-place noises come from two or more sources, their combined effect should be considered. Labor officials are concerned, because adding up the impact of each individual noise source often results in a lower noise exposure reading than if total work-place noise was measured.

Other provisions that would be killed include restrictions on the use of fixed electrical equipment near highly explosive liquefied petroleum gases, and requirements that structures supporting large tanks of flammable or combustible liquids be fire resistant.