Activated charcoal can carry 2,000 times its own weight in toxins (including heavy metals) which makes it an essential item for the first aid kit since it can save the life of a person who has accidentally ingested poison.
Activated charcoal is carbon (typically resulting from willow bark or coconut fibre) which has been subjected to air or steam at incredibly high temperatures, causing it to develop an extensive network of fine pores and become incredibly adsorbent. Adsorbency is different to absorbency in that it binds to the material in question and then carries it out of the body.
For digestive problems relating to food and water whilst travelling, you will need to mix a teaspoon of this black powder into a glass of water, stir well, and drink the full glass each morning. This same dosage should be used immediately after any suspected incidence of poisoning.
Brushing your teeth with a black powder seems like a counter-intuitive way to make your pearly whites whiter, but it truly works! To use activated charcoal for your teeth, just dip your toothbrush in plain water (or use a little natural toothpaste) and then dip it in the activated charcoal. It is messy and turns your mouth black, but after a rinse with pure water your teeth will be shining. This can also help to remove plaque as well as stubborn coffee stains.