Burning plastic is clearly a non-goal.

Most plastic foundation is made of polypropylene.

That's good news, as the melting points for the common plastics are:

PVC:   160 - 210 C 
HDPE: 210 - 270 C
POLY:  200 - 280 C

Any additives or impurities would likely lower the melt temperatures.

Steam sterilization is most often specified as 121 C for 15 minutes at 15psi, which seems safely below the melt point of any plastic that would be used.

The states that have autoclaves might be able to take their autoclaves and run "pure steam" rather than melting paraffin to sterilize frames of plastic foundation.
WVA has had a mobile bottled-gas-powered autoclave for decades, perhaps the most ingenious DIY hack in the history of beekeeping.
Steam pressure is not to be played with, one needs relief valves and a solid grasp of steam pipe fittings and such.  

Has to be worth a try, but the odds of large-scale AFB problems are small these days, as varroa have been the most effective mechanism ever in stopping the spread of AFB.

My own steam circulates in 1.5-inch pipe and in heat exchangers in my Bee-Quick stills, so I have no "autoclave" chamber to test this with, and I have everyone from the local Fire Marshall to the Dept of Homeland Security constantly looking over my shoulder and worrying about my solar steam plant, so I'm not going to add yet another "scary thing" to the apparatus mix.  (I wish more people could do math!)

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html