Activated charcoal is used as an antidote for many types of poisons. When mixed into a slurry and ingested, it bonds with the poisonous material, rendering it inert. The body then stops absorbing the poison, which allows it to pass through the digestive system. Activated charcoal can be purchased at most drugstores for a modest fee, but you can make your own at home provided you possess the proper equipment. Coconut shells make a good source of activated charcoal because of its absorbent properties, but you can use any nontoxic forms of wood and achieve similar results.
Strip a number of coconut shells free of any remaining meat or fibre. Wash them and let them dry completely to remove any dirt.
Place the coconut shells in a burning sink and burn them at a temperature of 302 to 482 degrees Celsius. Allow them to burn for at least 4 hours, until they are complete ash.
Remove the ash from the sink and place it in a clean plastic pail. Add enough CaCl2 or ZnCl2 25% chemical solution to completely soak the ash.
Allow the ash to soak in the chemical solution for one full day. That will transform it into activated charcoal.
Remove the charcoal from the pail and place it on a draining tray. Wash and rinse it thoroughly with clean, distilled water to remove all traces of the chemical solution. Allow the water to drain away for an hour or so.
Place the charcoal in an oven heated to 102 degrees Celsius, and allow it to bake for 3 hours.
Remove the charcoal and crush it into powder form using a hammer or an industrial blender. The grains should be as small as you can make them.
Store the activated charcoal in Ziploc bags until you need it. When treating poisons, mix 1/3 of a cup with 1 cup of water, then have the victim drink it. It also can be effective for alcohol and drug overdoses.
The sooner activated charcoal is applied, the better--within 30 minutes of ingesting the poison is ideal. After that, the body has absorbed the poison and the activated charcoal becomes less effective. (It acts as a "shield" around the poison to move it out of the body safely, which it can't do if the poison has been digested.)
Though activated charcoal is very effective, it should never replace a doctor's care. Call a physician as soon as possible after you have identified the poisoning and always follow his instructions to the letter.