4-6 Professional advice
If the smell of fume hood drainage is causing concern, check the condition of the "drain trap" of the hood’s drainage on the work surface or so.
Just like household sinks, a certain amount of wastewater is collected in the drain trap, so that the smell on the sewage side does permeate into the room.
This is called a water seal.
If the sinks are not used for a long time, the water in the trap may evaporate, and the water seal may become ineffective.
In such a case, if you let water flow for a while, the smell will eventually dissipate.
Another possibility is that the room is in an extreme negative pressure state.
If there is an imbalance between supply and exhaust air in a relatively airtight room and extreme negative pressure is reached, in rare cases, the negative pressure may exceed the height of the water seal and the odor of the sewage may be sucked into the room.
4-6 Advice for
Initial support/correspondnce
If the cause of the problem cannot be determined, consult with the laboratory manager or facility administrator and ask a specialist to investigate the plumbing / drainage piping.
