OSHA, WITH ITS $1.6 million fine against Chrysler last week, is showing a remarkable burst of new energy in enforcing its health and safety standards. That's the opposite of the performance you might have expected in the next-to-last year of the Reagan administration. Chrysler isn't going to fight the fine, the company said, and it promises to work with OSHA to ensure the protection of its employes.

OSHA -- the Labor Department's Occupational Safety and Health Administration -- found, among other violations, unacceptably high levels of lead and arsenic in the air at Chrysler's Newark, Del., assembly plant. The greatest dangers were being generated by painting and soldering operations that will be largely automated with the renovation next year of the Newark plant. "We know that OSHA discovered high lead levels in blood samples of two employes at Newark," the company said, "and we have taken steps to improve the monitoring . . ." Chrysler has also set up a task force with union participation to maintain surveillance over future compliance.

OSHA, an agency widely given up for dead earlier in this administration, is now at work with new force and vigor. The fine levied on Chrysler, $1.6 million, was the largest in OSHA's history. The investigative work preceding it was of a quality that led Chrysler not to challenge it. What's responsible for this turnabout?

One obvious part of the explanation was the arrival two years ago of an unusually able secretary of labor, Bill Brock. Perhaps another part of it was the election last fall of a Senate with a Democratic majority. OSHA will come before the Senate Labor Committee later this year for oversight hearings, and that's always cause for an agency to look to its record.

More broadly, tolerance for avoidable health risks has diminished sharply in this country over the past generation. Practices that people once accepted with a shrug are now seen as intolerable. Hazards earlier considered necessary to industrial production are now illegal, and new manufacturing technologies -- like the robots that will shortly be doing most of the painting and soldering at Newark -- provide the means to end them. The Chrysler case is an example of industrial health regulation at its most successful.