Does this mean that HDPE is safer than other kinds of plastic for hot food?
While I agree in principle, I wonder about the details. There is supposedly a difference between “microwave-safe plastic wrap” and non-microwave-safe plastic wrap, presumably a difference in the type of plastic, how it reacts when heated, and what the temperature limits are before bad things start to happen – though I’m also curious what exactly those bad things are and how bad it really is. Do you have any more information on the health effects and if certain types of plastic are better than others?
On the other hand, I do recall on occasions buying food from a convenience store, having the clerk heat it up in the microwave, and then noticing that the container seems slightly warped from the heat. This then becomes a complicated question of how much toxic effect is caused by how much heat.
On a related note, I recently heard that ordinary PET bottles of water or other drinks have the same problem, if stored in a sunny place. The sun and/or heat apparently can cause some kind of chemicals to be released into the liquid which you then consume. Again, though, it’s a question of degree.
I’m having a hard time picturing what kind of plastic bag would be used for this purpose; my image of a “plastic bag” is the thin, wrinkly kind you use for shopping, but I can’t imagine hot food being placed into one of those. What kind of plastic bags and what kind of food are you talking about?
Doing a bit more searching, it seems there is a cooking technique called “sous vide” (What Is Sous Vide?) that involves cooking foods that have been vacuum-sealed in plastic bags in not-quite-boiling water. One would assume that the plastic bags used for this style of cooking can withstand the not-quite-boiling liquid temperatures, so if such a bag is used to serve food, it might be safe.