The household detectors do not alarm in time to save your health, only your life. They alarm at one of three levels:
100 ppm for <90 minutes
200 ppm for <35 minutes
300 ppm for <15 minutes
So theoretically you could be at 90+ ppm for ever and it still wouldn't alarm.
The OSHA PEL-TWA is 50 ppm
The ACGIH TLV-TWA is 25 ppm
EPA says 9.5 - 12.4 ppm ave for 8 hours is unhealthy for sensitive groups
EPA says 12.5 - 15.4 ppm ave for 8 hours is just plain unhealthy.
So I'd want a detector that would let me know at an ave of 10 ppm at 8 hours or provides digital read out of peak levels on demand down to 10 ppm.
Monona
In a message dated 6/9/2010 3:03:11 PM Eastern Daylight Time, mattlundgren**At_Symbol_Here**BOISESTATE.EDU writes:
It seems we have more and more labs wanting to work with carbon monoxide and
I'm wondering when you require a detector and what type. Where do you draw
the line for requiring a detector? Do you allow residential detectors for certain
processes? When do you require a detector be linked into a communication
system for alarms, security, etc? Is this based upon quantity, the process, all of
the above? The labs will have quantities ranging from 80-140 cubic feet in a
single cylinder.
Thanks,
Matt