Consumer Product Safety Commission Chairman S. John Byington has resigned his post effective June 30, in what he called an effort to "depoliticize" coming congressional hearings into the activities of the be-leaguered agency.

Byington, 40, was one of two remaining Republicans heading up independent regulatory agencies, and ever since he was confirmed in May 1976 - following six months of bitter confirmation hearings - he and the agency have been the target of criticism from both inside and out.

The worst of the criticism has come in recent weeks after the release of a Civil Service Commission study citing several alleged personnel abuses at the CPSC. Several press reports revealed widespread discontent with the commission's accomplishments from many of those who first supported its creation almost five years ago.

And last week, a CPSC internal planning document revealed that the agency anticipated continuing difficulty in doing its job while faced with tighter budgets and an increased mandate.

"No matter what we did, or what we said, nobody wanted to hear anything positive," Byington said in an interview yesterday. "We just weren't getting through in sucha political environment."

"I really think the agency is a hell of a lot more imporant than any indi-be done to get the focus on the vidual," he said. "And we've got to ry and figure out what, if anything, can be done to get the focus on the agency, where it belongs."

He said that he felt the agency was approaching a critical time. "The summer is going to be taken up by the commission really studying its course for the next four years by setting up its operative plan for fiscal 1979 and finalizing its budget submissions for '80, '81, '82," he said.

Byington, whose term would have expired on Oct. 26, 1978, said he felt the new chairman should "play the major leadership role in those kinds of decisions that are certainly going to impact (his or her) first four years as chairman."

Byington said his decision came after a weekend trip to Florida where he saw his parents, and discussed his options. He also and he wanted to give President Carter time to get his two new appointees to the commission, Susan King and Edith Barksdale Sloan, confirmed. Their confirmation hearings begin today.

Byington said he could not resign immediately because only three of the five positions on the commission are filled, and two persons could not keep it moving.

Byington also faces a gruelling set of congressional hearings in the coming months - hearing that were sure to focus on him and charges made about his and the agency's activities.

In two weeks, he goes before House oversight and appropriations subcommittees working on the CPSC budget and, following that, he goes before correponding Senate committees.

In the Senate, Wendall, Ford (D-Ky.), long an outspoken opponent of Byington, had called for the chairman's resignation two weeks ago, following publication of the Civil Service report. Byington called Ford personally with the news of his resignation yesterday.

Ford's office released the following statement from the senator yesterday afternoon:

"It is my opinion that Chairman Byington's decision definitely is in the best interest of the commission. I believe he'll find that I will continue to directo my energies to improving the position, ability and effectiveness of the CPSC."

President Ford in November 1975 to head the CPSC, he had served a year and a half as White House deputy special assistant for consumer affairs under Virginia Krauer. Prior to that, he had worked in the Commerce Department.

But his contribution to the agency was his management expertise, acquired partially from his earlier post as executive vice president and chief operating officer of Intermart Inc. of Michigan. Byington is a native of Grand Rapids, Mich.

Clearly Byington's proudest achievement has been the role of the CPSC in an interagency task force with the Environmental Protection Agency, Occupational Safety and Health Administration and the Food and Drug Administration to study federal regulation of chronic hazards.

The CPSC role as the lead agency in that effort is also up in June.

Byington inherited a badly managed bureaucracy with a blacklog of more than 180 cases. Although he has produced that backlog dramatically, and has streamlined management operations considerably, he has not succeeded in silencing critics who claim the 900-person agency has accomplished little. Congress has cut the CPSC budget for four straight years.

In his letter of resignation sent to President Carter yesterday, Byington said "events of the past month have convinced me that it is in the long-term best interest of the CPSC to take some action to depoliticize the enironment in which we operate by accelerating the timing of your naming a new chairman."

He cited "the political harassment which in recent months has increasingly swirled around me in particular and the agency in general, and has significantly detracted from our ability to function and overshadowed our excellent record of consumer product safety protection that the CPSC is now achieving.