California breaks 'ergonomic ground.' (Occupational Noise and Ergonomic Hazards rule)

Ergonomics is an increasingly important issue. Based on Bureau of Labor Statistics and workers' compensation data, the number of musculoskeletal disorders has risen tenfold since 1980. Ninety-two countries have completed or begun the process of developing ergonomic mandates and standards to help ensure the health and safety of workers.

In July 1993, the governor signed a law mandating that statewide ergonomic requirements be developed by the end of 1994. As a result, the California Standards Board proposed the Occupational Noise and Ergonomic Hazards rule.

This ergonomic rule is nationally significant because California has taken the lead on several occupational safety and health issues with the result being adoption by other state legislatures.

One part of the California ergonomic rule details the minimum compliance requirements for companies where workers use computers more than four hours a day or 20 hours a week. These requirements include:

Chairs

* Seat Height should allow the user to place feet firmly on a support surface.

* The maximum seat depth should permit contact with the backrest in the lumbar area and be designed to avoid increased pressure on the back side of the lower leg.

* The seat pan angle should generally ensure that the angle between the upper and lower leg, with the lower leg perpendicular to the floor, is between 60 and 100 degrees. (Exception: Where the seat pan angle is adjustable and the employee can readily adjust it to a comfortable position.)

* The angle between the seat back and seat pan should permit the user to assume a working posture with a torso-to-thigh angle of at least 90 degrees. (Exception: Where the seat pan angle is adjustable and the backrest is adjustable to angles ranging from behind the vertical position to forward of the vertical position.)

* The backrest should be at least 12 inches wide and support the lumbar region.

* The minimum distance between armrests, if present, should at least be equal to the user's clothed hip breadth.

* Forearm supports, if present, should be removable if they are not adjustable.

* The adjustment mechanisms for adjustable seat pans and backrests should be easy to operate.

Computer Work Stations

* The VDT screen should be positioned so that the entire primary viewing area of the screen is 0 to 60 degrees below the horizontal plane passing through the operator's eyes.

* The keyboard, in conjunction with the chair and work surface, should be positioned so that the user's forearms, wrists and hands are parallel to the floor when operating.

* Work surface height should provide adequate clearance for the operator's legs in his or her most comfortable position.

Work Station Accessories

* An adjustable document holder and arm, wrist and foot rests should be provided at the user's request.

Lighting

* Lighting for computer work stations should be arranged to avoid glare and visual discomfort.

* Glare from natural and overhead light on computer screens and keyboards should be minimized as much as possible.

Computer Screens

* Screens should be clean, clear and flicker-free.

Work Breaks

* VDT operators should receive alternative work or a rest break for at least 15 minutes following each two-hour period of repetitive keyboard work. Where the pace of repetitive keyboard work is automated or controlled by a mechanical or electronic device, alternative work should be provided for at least five minutes every hour.

Paul Williams is supplements editor for the Los Angeles Business Journal