Yes. Fentanyl / Carfentanyl can be absorbed, ingested - eaten / drank it is water soluble, injected and or inhaled.
Your mouth is very vascular and can easiliy absorb medications.
We had several LEO's while securing a vehicle of a drug overdose get substance on their skin and it put both of them down, they were transported to the ER and resuscitated and were eventually ok, but the stuff that is out there is really bad shit.
Paramedic anon