Fume hoods, essential safety devices in many labs, need regular inspection and maintenance to ensure they are functioning properly. Testing frequency can depend on a variety of factors, including the type of work being done, the specific equipment being used, and local regulations or institutional policies.
As a general guideline, the U.S. Occupational Safety and Health Administration (OSHA) and the American National Standards Institute (ANSI) recommend that fume hoods be inspected at least annually.
This annual inspection typically includes:
Face velocity measurements: This is a measurement of the speed at which air is drawn into the fume hood. It's important that this speed is within the appropriate range to effectively contain and exhaust harmful or dangerous fumes.
Visual inspection: This includes checking the general condition of the fume hood, the sash (the movable "window" of the fume hood), the interior surfaces and lining, the ductwork, and the exhaust fan.
Alarm and monitor tests: If the fume hood is equipped with a monitor or alarm system to indicate improper functioning or unsafe conditions, this system should also be tested.
Containment tests: These tests, such as the smoke test, are designed to ensure that the fume hood is effectively containing and venting fumes, with no "leakage" or escape into the lab.
If a fume hood is used heavily or for particularly hazardous substances, it might need to be tested more frequently, potentially every six months or even more often.
Remember to check with your local or state regulations and guidelines, or consult with your institution's environmental health and safety office, for the specific requirements and recommendations in your area or field. MTI can help you with what your local regulation is but lets keep employees safe.