How to Keep Odors from Coming Back into Your Workplace

Are the air vents at work emitting bad smells?

A few years ago Mitsubishi workers, members of UAW Local 2488 in Normal, Ill., complained of gasoline vapors coming out of the fresh air vents.

“People complained every time the 10,000-gallon gas storage tank was refilled,” says Tim Denaro, first-shift safety representative.

Then the UAW health and safety team discovered that the pressure relief pipes for the tank ran up the side of the building and were vented about 3 feet from a fresh air intake.

After the UAW filed an OSHA complaint, the company moved the pipes to a different location.

The UAW’s new collective bargaining agreement with Mitsubishi outlines a process to study and improve the smoke stacks on top of the plant.

Many of the problems at Mitsubishi have to do with the initial build of the plant, says Denaro. “One of the worst stacks was way too low,” adds Dennis Drnjevic, second-shift safety representative. So the company had to raise the stack.

To deal with persistent problems, the company and the union are jointly developing a process to uncover odor sources.

They are developing a new system of logging complaints from the shop floor about odors from the fresh air vents. Smoke tests will be performed to track the re-entry of fumes.

So the Mitsubishi workers are solving their problem--one that afflicts all too many workplaces.

What causes bad air to recirculate inside a plant?There are many possible causes:

• Poor building design can locate fresh air and exhaust stacks too close together.
• Wind may carry contaminants across the roof of a building into an open loading dock door.
• Negative pressure, created when there is more exhaust coming out of a plant than fresh air coming in, can pull in bad air through open skylights.

To avoid these problems, here are some suggestions:

• Do not locate air intakes at ground level or below ground level. The lower one-third of a tall building is high enough to avoid wind-blown dust, vehicle exhaust, tobacco smoke, grounds-keeping activities, and intentional human contamination.
• Find and remove or minimize potential intake contaminant sources.
• Separate intakes from potential contaminant sources.
• Install louvers or grills (including bird screens) over intakes.
• Keep air filters and scrubbers in excellent operating condition.
• Restrict tobacco smoking near intakes.
• Don’t locate the intake within an architectural screen if it also contains a contaminant source (example: exhaust outlet).

To provide protection against intentional contamination--concerns that have been heightened since Sept. 11--air intake security measures should be included in existing and future building security plans.

The UAW Health and Safety Department recommends that plants that need serious work hire a qualified professional to do the retrofit.

Further information can be found in the UAW Health and Safety Department’s Nov. 5, 2001, newsletter at: www.uaw.org/hs.