Those of us who work in biological labs always have
parafilm around to seal flasks and test tubes. It is a thin waxy sheet material that is ductile and waterproof. My co-worker and fellow looney mentioned in passing that he used to use it as a firestarter in the Kenyan bush. He wrapped it around a few sticks to start his fire. So we lit some with a match from my EDC. Burns well!
More importantly, parafilm is great for sealing things. From now on I will be sealing my kits with parafilm both for waterproofing and as a backup firestarter.