A seal check must be done each time a respirator is donned!
The purpose of a seal check is to see if there are air leaks.
Positive Seal Check: Cover the respirator completely with both hands, and exhale sharply. If air blows on your face or eyes, readjust the respirator accordingly. Do not use the respirator until you have passed the seal-check.
Negative Seal Check: Breath in sharply, respirator should collapse/seal to face. For elastomeric respirators with filter cartridges, block filters with hands and breath in. Respirator should seal to your face and not go slack.
Not every respirator can be checked using both positive and negative pressure. Refer to the manufacturer’s instructions for conducting a user seal check on a specific respirator. This information can be found on the box or individual respirator packaging. Respirator should be worn for 5 minutes before fit test starts.
