Fumehood Shutdown Policy
When a fumehood is tagged with a "Do Not Use This Fumehood" sign, the hood is not to be used for any purpose, even for the removal of a chemical. The sash/glass of the hood is to remain closed. (When working on a hood, Facilities employees realize that they are exposed to any fumes going up the hood. However, they do not have the chemical background that we have that would allow them to differentiate between safe and unsafe chemicals/conditions. Therefore, we should be sensitive to their concerns and err on the side of caution.) In the case of an unscheduled emergency shutdown, you may only open the hood to shut down any reactions which would pose a safety risk if left unattended.
Planned Maintenance Policy
Facilities workers are routinely working on the fumehoods. Most of the time, the work is preventative maintenance (which occurs once a year) and Facilities can schedule their work with plenty of advance notice. The worker will place a work notice on the hood warning of the impending shutdown and indicating what actions should be taken to prepare the fumehood for shutdown. Prior to the actual shutdown, any chemicals/experimental setups needed by researchers during the time frame indicated and are stored in the hood itself should be removed. Chemicals may remain in the cabinets beneath the fumehood and accessed as needed. Experimental setups, reactions, and stills do not need to be removed as long as they are shut down and sealed. Closed chemical containers may remain in the hood as long as they are not accessed during the shutdown. It is also the researcher's responsibility to ensure that there are no open containers in that hood. The workers do not know what we are working with and we need to be sensitive to their concerns. Therefore, we should even cover open water baths, etc., with aluminum foil so that there are no safety concerns. When actually working on the hood, the worker will tag the hood with a "Do Not Use This Fumehood" sign at which point the fumehood may not used at all and the sash/glass of the fumehood must remain closed.
If you are doing an important experiment, etc., the workers are more than willing to try to accommodate your needs but access to the hood is only permitted after Facilities removes the "Do Not Use This Fumehood" sign. By cooperating, we can minimize the impact of the fumehood shutdown to our researchers as well as show our concern for the safety of Facilities workers.