[Govyn]

Hi everybody,

I'm updating/upgrading the respiratory protection plan where I work and I had a few questions about acetone. Here's the setup:

My workers are allowed to have 0.002 m3 (0.5 gal) of acetone at their workstation at all times. If they run out or if it gets too contaminated they may replace it. I need to find out how much acetone they are exposed to during the day and to make sure it does not exceed the PEL (8 hours) value of 1200 mg/m3 or a STEL (15 mins) of 2400 mg/m3.

I have made the assumption that their immediate breathable space is 2.25 m3 (1.5m*1.5m*1m). My MSDS indicates that the evaporation rate of acetone is 7.7 BuAc (where BuAc=1).

I need your help to get a final mg/m3 value to compare to the PEL value...If I could get an evaporation rate I could work with then I'll be good to go.

Any and all help is appreciated.

Thanks again and have a good day

[typhoon2028]

You should really perform a time weighted study.

Companies who perform work area air quality will rent out little air pump monitors.  The monitors come with some kind of material that absorbs different chemicals.  If you tell them what chemical you are testing for the can measure how much acetone the employee is exposed to.

Basically, one day people would wear little pumps with a tube and filter.  Also, they may mount one of these pumps in the area to determine worse case.  The filters get sent off and analyzed.

[Govyn]

I completely agree with you. We have tests like that done with styrene a couple times a year. According to the hygienist that conducts the tests, the acetone and styrene interfere with each other. The acetone artificially hikes up the measured quantities of styrene, we are borderline but still under. That's why I'm looking for a theoretical approach. I want to use the theoretical results to see if further and more controlled testing is required. For example, if the theoretical results are half of the PEL, then I'll feel good saying my workers are safe (for acetone at least) but if the theoretical results are 10% under, then I'll look for a more controlled test.

I hope that explains my situation a little more.