The Occupational Health and Safety Administration says its new proposed rules on ergonomic injuries will provide needed protection to millions of workers harmed by the repetitive keyboarding motions of the new economy and the lifting and pulling of the old. Business says the rules are vague and open employers to endless liability for ill-defined ailments.

There are elements of truth in both arguments. OSHA is correct in asserting that the changing workplace demands changing protections for workers. Business is understandably concerned with the proposal’s underlying assumption of guilt, that every musculoskeletal disorder — sore back, tendinitis, carpal-tunnel syndrome — is caused on the job unless the employer can prove otherwise.

There are also elements of exaggeration. With the public-comment period on these rules just beginning, business groups were hasty in predicting economic collapse and in threatening litigation. OSHA makes claims about the cost/benefit ratio of the rules that must be verified. The cause of the pandemic of injuries it describes needs further examination, the definition of work-related injury is fuzzy, the trigger for employer liability is too sensitive.

Under the proposal, the liability trigger gets pulled if a workplace reports a single recordable ergonomic injury that the job can be assumed to have caused. At that point, the employer must analyze all the jobs in that category and develop a plan to eliminate the hazard. The injured worker is eligible for up to six month’s leave at 90-percent pay. The old difficulty of determining when, how and where a worker got hurt remains, as does the even greater difficulty of determining when the worker is healed. OSHA’s claim that the $4.2 billion cost to business of implementing these rules will be offset by double that amount in savings — less lost time, higher productivity, lower insurance premiums — sounds too convenient to be swallowed whole. The flexibility and common-sense approach OSHA says is a hallmark of this proposal has a dark side for employers; it leaves a lot of discretion for citing violations and assessing liability in the hands of individual inspectors.

Rarely has business reacted so swiftly and violently to proposed regulations and OSHA asked for it. This proposal was been in the works for years; the agency easily could have addressed many of the fundamental concerns by bringing employers into the process. The release of the proposal — just days after Congress adjourned and thus was unable to mount organized objections — is suspect. With the campaign season now fully under way, the timing and nature of the plan seem awfully political, calculated to widen the rift between labor and management.

Certainly, employers have an obligation to provide safe workplaces and to help workers injured on the job. But the regulators, with this artless approach, have turned what should be collaboration into confrontation and the only remedy is an open, accommodating and receptive comment period that leads to reasonable modifications. It will take some heavy lifting to make this right and OSHA must shoulder most of the burden.