was at the hardware store today and saw tire plug kits. the also have refills that are just the black, goopy, string-like things. they would fit nicely in a straw and was wondering about their use in firestarting. they are 'highly flammable' as stated on the package and contain heptane. this is where my question is. anyone know what heptane is and is it hazardous. the package has a warning about inhalation, but i imagine that inhaling petro soaked cotton isn't that great for you either. again, just a quick brainstorm, and looking for more info??