Ventilation Equipment

When installed or modified and at least annually thereafter, fume hoods, fume hood exhaust systems, and laboratory special exhaust systems should be inspected and tested as follows:

• Visual inspection of the physical condition of the hood interior, sash, and ductwork
• Measuring device for hood airflow
• Low-airflow and loss-of-airflow alarms at each hood
• Face velocity
• Verification of inward airflow over the entire hood face

Changes in laboratory conditions that might affect hood performance such as system rebalancing and a change in the source of make-up air should trigger an inspection and test.

Deficiencies in hood performance should be corrected or one of the following should apply:

• The activity within the hood should be restricted to the capability of the hood.
• The hood should not be used.