By John S. McClenahen The U.S. Senate, using the six-year-old and previously unused Congressional Review Act, is expected to vote, possibly as early as today, on whether to junk OSHA's controversial workplace ergonomics rule. Both business and labor groups expect the Senate vote to be "close." The sweeping standard, which took effect in mid-January and carries a mid-October compliance date for manufacturers, has drawn the ire of many businesses. "OSHA's $18 billion regulation will tie the hands of small companies like mine with increased cost and paperwork, with no guarantees that the safety of my employees will be enhanced," complains Arthur D. Wainwright, chairman of Wainwright Industries, St. Peters, Mo. and vice chairman of the National Assn. of Manufacturers (NAM). Indeed, stopping the OSHA ergonomics rule is the top public-policy priority of 55% of the manufacturers that the Washington-based NAM recently surveyed.