You may also encounter other types of local exhaust. Images show a few examples.
These types of exhaust systems have very limited application. If you encounter one of these types of systems, you need to determine the identity of the contaminants of concern, approximate amounts, type of operation, length of time of the operation, and frequency of the operation. It is also important to find out from the occupant whether they are using these devices for a perceived worker protection function or trying to capture simple nuisance odors, heat, etc. This information will allow you to consult with a Senior Specialist about the appropriateness of these devices for the intended use and whether a follow-up respiratory hazard assessment referral to the appropriate program specialist is needed.