Posted By steve e ashton
Alarms might be needed - it depends on the potential consequences of failure.

In my lab days, we used to provide an 'indicator' on the front of fume cupboards - essentially a strip of tissue taped to the bottom of the sash. If the tissue stopped fluttering, we closed the sash and stopped work until the system had been repaired or more often) unblocked. Very low tech, and inexpensive - but our only issue at that time was nuisance dust...

Steve

Posted By garyh
Surely the answer is - this would be risk based.

I once worked in a lab environment where we used "uprated" fume cupboards to deal with very nasty things such as carcinogens. Since failure of the fume cupboard LEV could lead to unacceptable exposure, the fume cupboard was alarmed.

However.........the alarm was on the motor; the motor drove a fan via a belt. One day the belt slipped off; I noticed a lack of "draught" - the alarm had not gone off!! (Yep, we should have hazopped it!!)

To summarise, if the LEV is "safety critical", based on a competent COSHH assessment, then alarm it. I don't like to passive paper strips idea on critical kit though; it is too passive.

For low risk situations I would say it is a good idea, though.