I'm more interested in how tinder behaves under non-ideal conditions where the user is careless. A good test would be to carry both PJ cotton balls and WD-40 cotton balls in unsealed containers for a few months, and be careless with the containers. The mineral spirits in the WD-40 would evaporate, but the question is whether or not the remaining oil would be sufficient to keep the cotton flaming for over a minute. I already know the PJ cotton balls would pass the test.