While occupational overexposure to potent opioids like fentanyl are theoretically possible, it is likely only under limited circumstances. I supported a facility that was a primary producer of the active pharmaceutical ingredient (API) of fentanyl in kilogram quantities and initially we kept EMTs in level1 suits with naloxone in adjacent room during handling but never had a mishap during my tenure. Consider this in deciding needed emergency response and likelihood of generating a respirable dust:
1) potency of API
2) purity: whether mixed with inactive ingredients
3) quantity handled: mg vs kg
4) physical form, whether powder or liquid
5) energy applied to API, like milling grinding or tableting
6) engineering controls used: ventilated enclosures vs open bench.
Many potent opioids can be safely handled if using techniques like used for antineoplastic drugs. If in doubt get EHS staff to review, there are lots of resources under “safe handling of potent pharmaceutical compounds”
Tom Kibby, MD MPH