Milk Jugs
I just gotta ask...
what's the deal with milk jugs? Think about it...most plastic milk jugs come in two forms, the returnable ones with about a 2mm wall thickness, and the "recyclable" ones, about 0.15-0.3 wall; both are made of polyethylene, although the returnables have a somewhat heavier molecular weight due to the metal crosslinking polymers.
Now, the average red plastic gas can is made of PE as well, as is the quart oil bottle, and the gallon anti-freeze jug. All of them outgas plasicizers and some dyes, and all are permeable to shorter hydrocarbon molecules. Of course, the thinner, lower-quality milk jug is going to be much more permeable, and since the regrind (recycled plastics) content is variable, it is possible that some unfriendly molecules could be contained in them. But, for moldability, the regrind content is often held below about 7%, and given the costs involved in cleaning, handling and blending, regrind is not usually present in most packaging.
So what is the mechanism for gas from milk jugs burning saws down, and will I have to go back to a steel gas can?