I was thinking about this at work today. When you ship "hazardous materials", DEpt of Transporation regulations come into play, at least for shipping in the US.
So DOT regs say the hazards must be visible to those involved in the transport and the materials packed ina manner to prevent spills and exposures Thus, the overpack with the polybag, as a method of secondary containment. Thus, the hazard warning labels on the bag for the shipping, receiving clerks and drivers. All this may very well be for the notification of others and not the patient.
I went and looked this up today, and it appears pharmaceuticals are part of those DOT regs. In fact, hospitals are supposed to ship drugs and biologicals in a manner compliant to the regs. I get my gleevec from the hospital pharmacy, and I get it in a FedEx envelope, no hazards on it, no secondary containment. In fact, I kinda doubt FedEx knows what is in there. So either they don't know the regs, or the regs have more wiggle room than my brief perusal of them revealed.
Traci