Reading Reg's post (106) about 'hot fill' I did look up what it was, a lot of juices get hot filled into PET bottles which can take close to boiling. For the bog standard plastics I came across this list.
What are the hot fill temperatures for the plastic bottles?
Hot fill temperatures for plastic bottles and jars.
PET (polyethylene terephthalate) 120°F
PS (polystyrene) 150°F
HDPE (high density polyethylene) 145°F
LDPE (low density polyethylene) 120°F
PP (polypropylene) 165°F
PVC (polyvinyl chloride) 140°F
NOTE: The information provided above is intended to provide a relative comparison of plastic resin hot fill temperatures and should only be used as guide during the selection process. Individual plastic bottle resins may have hot fill temperatures that vary from those listed above. It is the buyer's responsibility to make the final determination as to whether a given bottle is suitable for their hot fill process. Chemical and temperature compatibility testing is, and will always be, the final determining factor in the bottle selection process.
just put my first brew in the 55, should have read this first i guess... transferred in at 60 degrees and left it overnight, had a look this morning and there are dints where it touches the frame, should have cooled it down a bit more but thought 60 should be ok. normally id droip it to about 40 but it was late at night and way past my bedtime.
will try putting some hot water in it to see if i can pop them out a bit later but i would be doubtfull.