Washington Employers Concerned about Regulating Ergonomics and other business groups filed the suit, claiming the rules written by the Department of Labor and Industries burden employers while providing dubious benefits to workers.

"Like the federal ergonomics proposal before it, Washington state's ergonomics regulations are unsound procedurally, legally and scientifically," said the National Association of Manufacturer's Deputy General Counsel Quentin Riegel. NAM is one of the groups supporting the suit.

"There is simply no 'up-side' to these regulations, and we hope the court will intervene on our behalf," Riegel said.

Employer and business groups charge that the state did not follow proper procedures in drafting the regulations; that the rules fail the cost-benefit test; that they are not the least burdensome alternative, as required by state law; that there is no reasonable evidence supporting the rules; that it reaches beyond the workplace to cover conditions not related to work; and that it is not coordinated with other state laws governing the workplace.

The department has no plans to rescind or revise the regulations, much to the relief of labor unions in the state.

Washington state requirements are to be phased in over six years beginning next July. Employers will be required to identify tasks that are likely to cause back strain, repetitive stress and other injuries to muscles and joints.

Businesses - starting with sawmills, construction and other industries that report the highest number of injuries - must take steps to lower the risks by buying new equipment, repositioning existing equipment or providing training on how to avoid injury.

Major employer groups say the rules will cost them $725 million a year. The lawsuit also challenges the effectiveness of the ergonomic techniques spelled out in the rules.

Proposals to delay implementation of the rules died in a closely divided state legislature this year.