In an unusual move that split the Consumer Product Safety Commission 3 to 1, a majority of the members warned yesterday that the agency's ability to safeguard consumers will be "substantially impaired" if the CPSC budget for fiscal 1984 is held to the proposed $32 million and 595 workers.

Commissioners Edith Barksdale Sloan, Stuart M. Statler and Sam Zagoria expressed their concern in a letter to the House subcommittee on HUD-independent agencies, which has jurisdiction over the CPSC budget.

Included in the letter was an analysis of the impact of current and previous budget restrictions, which the commissioners said had forced the agency to "cancel or delay numerous critical projects."

Chairman Nancy Harvey Steorts declined to sign the letter, insisting that the agency can be viable with the proposed budget. "This is a tough budget year," Steorts said in an interview after the hearing.

"If everyone asks for more money, it puts a squeeze on the government."

Steorts said she wouldn't turn down more money if Congress decides to award more to the agency, which has been buffeted by budget cuts under the Reagan administration. In fiscal 1981, for example, the CPSC budget was $42.1 million and 889 workers. In the current fiscal year, the agency has $33.5 million and 636 workers.

The CPSC had requested $35 million for fiscal 1984, but that proposal was trimmed to $28 million by the Office of Management and Budget. Some of those cuts were restored later by OMB and the proposal set at $32 million.

In their letter, the three commissioners urged the committee to provide the agency with the budget and the resources needed to carry out its mandate to protect American consumers against unreasonable risks from consumer products.

They said that the CPSC has sustained greater cuts than any other federal health and safety agency. And they said that current and previous budget reductions have forced the agency to cancel or delay investigations of deaths and injuries associated with many products under its jurisdiction, including chain saws, because of lack of funds.

In addition, they said CPSC turned down an invitation from three national family magazines to list a CPSC publication on children's safety because of lack of funds to supply the anticipated requests.