Activated charcoal: An effective treatment for poisonings

What is activated charcoal?

Activated charcoal is made by burning carbon-rich materials, such as wood, at very high temperatures to create charcoal. The resulting product is a black, odorless powder. The charcoal is then "activated" through a special process that makes lots of holes and crevices in the charcoal particles to increase their exposed surface area. One teaspoonful of activated charcoal has about the same total surface area as a football field! This huge surface area causes other substances to stick to the activated charcoal particles. This process is called adsorption (not absorption).

What is not activated charcoal?

Some people have attempted to use burned toast or ground-up charcoal barbeque briquettes as substitutes for activated charcoal. The only thing these have in common with activated charcoal is their black color. Some briquets are treated with chemicals to make them easier to light, and these chemicals were never intended to contact human skin or to be ingested.

Activated charcoal and poisoning

When people are taken to an emergency room because of a poisoning, they might expect to have their stomachs "pumped." In reality, gastric lavage (stomach pumping) does not happen very often. Most poisonings are treated with supportive care, but there are situations in which preventing the absorption of a swallowed poison can avoid or minimize the toxicity of the poison, and this is when activated charcoal is used.

The black powder is mixed with a liquid and either swallowed or poured down a tube into the stomach. Once in the stomach, activated charcoal can adsorb many poisons and reduce their absorption into the body. The sooner activated charcoal is given after the ingestion of a poison, the better it works.

Activated charcoal is typically mixed with water, but it can be mixed with a sweet, noncarbonated beverage for children. Some activated charcoal products contain sorbitol that adds sweetness and is also a laxative. Some studies show that pushing the poison through the gut faster with a sorbitol laxative can decrease the amount of poison that is absorbed from the gut.

An early demonstration of the adsorptive properties of activated charcoal occurred in 1813 when the French chemist Bertrand drank 5 g of arsenic trioxide (a very poisonous substance) mixed with activated charcoal and survived. Do not try this at home!

Can you take activated charcoal at home?

Some activated charcoal products sold over-the-counter make claims of adsorbing toxins and decreasing bad breath. It is not recommended to use activated charcoal at home to treat a poisoning. If a poisoning is serious enough to warrant the use of activated charcoal, the person should be monitored in an ER. Over-the-counter products might not be as "activated" as the activated charcoal used in the ER, so would be less effective. Over-the-counter activated charcoal typically comes in 250 mg tablets. Providing the same dose given in an emergency room would require hundreds of tablets.

Other uses of activated charcoal

Activated charcoal is commonly used in water filters. These filters need to be replaced regularly because the activated charcoal can become saturated with adsorbed material. Activated charcoal has been incorporated into toothpaste (for whitening) and some skin cosmetics. Its usefulness in these situations is questionable. Activated charcoal is used in some products to adsorb odor-causing substances.

Risks associated with activated charcoal

Overall, activated charcoal is well tolerated. The few adverse effects of activated charcoal include nausea and vomiting after drinking it, often in response to the gritty feeling of the mixture, and inhaling (aspirating) the dry activated charcoal powder or the liquid slurry. This could happen if the patient is very drowsy.

Activated charcoal should not be taken by anyone with gastrointestinal bleeding, a bowel perforation, or a bowel blockage.

Have more questions?

Have more questions about activated charcoal? Consult the webPOISONCONTROL online tool for guidance or call your poison center at 1-800-222-1222. Whether online or by phone, expert guidance is always free, confidential, and available 24 hours a day.