A Consumer Product Safety Commissioner said yesterday that another commissioner or CPSC staffer leaked confidential information to the manufacturers of a certain style of baby gates, and that the leak may have seriously impaired the safety of small children.

CPSC Commissioner Stuart Statler contended that information from a closed-session CPSC meeting was leaked to the makers of accordion-style gates, which the agency had deemed unsafe, and may have encouraged the companies to ignore an earlier CPSC letter and continue manufacturing the products.

"To me, this is as reprehensible as what Rita Lavelle at EPA did in allegedly divulging sensitive enforcement information to Dow Chemical," Statler said.

Baby gates are barriers designed to bar infants and toddlers from doorways and stairways. Last month, CPSC's enforcement staff sent a letter to the makers of accordion-style baby gates urging that production and distribution be halted because a baby could be killed or injured if his head were trapped either in the diamond-shaped slat openings or the V-shaped openings at the top of the gate. Three non-accordion styles of gates are safe, according to the commission.

What was leaked, Statler said in a press briefing, was the fact that the CPSC was disputing the authority of its staff to send the letter urging the ban when the letter had not been approved by all the commissioners. The dispute surfaced at a closed CPSC meeting last month.

The intra-agency squabbling over the issue comes as the CPSC awaits the White House nomination of a new chairman to replace Nancy Harvey Steorts, who will step down Jan. 5. The criticism of a breach of confidentiality yesterday appeared to be aimed at Commissioner Terrence M. Scanlon, a leading contender for the chairmanship, sources said.

"This whole thing was an attempt to embarrass Scanlon," said Aaron Locker, a Scanlon supporter and attorney representing three manufacturers of the accordion-style baby gates -- Paris Industries Corp., North States Industries Inc. and Nu-Line Industries, a division of Memline Corp.

Scanlon often has sided with the Reagan administration and opposed Steorts and Statler on key commission votes.

"Today's meeting was really an extreme example of the different points of view at the CPSC over which direction a regulatory agency should take toward industry," a commission source said.

"These aren't safety gates -- they're unsafety gates," said Statler, who complained that the product is still being manufactured.

Statler wouldn't say who leaked the confidential information questioning the letter's validity.

He said that the leaked information specifically concerned a staff-initiated letter sent to baby-gate manufacturers throughout the country on Nov. 9. The CPSC letter said that "to prevent future death and serious injuries from occurring with this . . . gate, we now urge you to stop manufacture and distribution of the accordion-style gates immediately."

After this letter was sent, Scanlon protested that he hadn't approved the letter. Several other commissioners also indicated surprise that the "urging letter" had been written before a scheduled upcoming briefing of the commissioners was held, Statler said.

The CPSC director of compliance who authored the letter said yesterday he had transmitted it to the commission through the executive director, but it was never forwarded to the commissioners.

After the baby-gate makers learned of the internal CPSC flap, their lawyer, Locker, wrote the commission on Nov. 28. "Your letter on the letterhead of the commission tends to be treated as a letter and request from the commission itself. This is hardly the case, as you readily admitted at the meeting."

"How would he know what happened in a closed-session meeting?" asked Statler. "I would like to know just how Mr. Locker found this information out."

The compliance director who wrote the original CPSC letter next attempted to write Locker to clarify what he called "an unfair misstatement and inaccurate characterization" by Locker of what was said in the confidential meeting. But the staffer said he was prevented from sending his letter out by Scanlon.

When the CPSC first began addressing the baby-gate issue in 1981, there had been four deaths and eight incidents related to accordion-style baby gates. Since that time, the gates have been linked by the commission to four more deaths and 15 more incidents.

Locker, in his letter, argued that the staff letter to baby-gate manufacturers was an example of "backdoor rulemaking. . . . It is notrulemaking by adjudication but, in its effect, the imposition of a ban by letter of a single agency executive."

Statler disagreed: "It's not backdoor rulemaking. This is backdoor collusion."