As I promised a week ago (https://lnkd.in/eDtg5g83), I've measured my exposure to 2,3-pentanedione during the grinding of coffee at the big box store BJ's. I measured using an SKC ultra sampler (Tenax-TA) for 5 minutes, the time it took to grind the 2.5 lbs. bag of BJ's Organic Sumatra Estate. Analysis with our GC-MS using thermal desorption shows both diacetyl (11 ppb) and 2,3-pentanedione (25 ppb) to be present and in significant concentration. Since my exposure to these chemicals was for only 5 min, this big box store grinding activity is judged to be safe since the short-term safe exposure limit (15 min exposure) is 25 ppb for diacetyl and 31 ppb for 2,3-pentanedione. Breathing vapors of this concentration all day (8 h), however, is potentially harmful since the 8 h limit is 5 ppb for diacetyl, and not so different for 2,3-pentanedione. Businesses that require employees to work near grinding operations need to be routinely monitored and ventilation be used to control exposure.
