Is bamboo charcoal safely edible?

Question

Bamboo charcoal is made up of pieces of bamboo, which are taken from plants five years or older and burned inside an oven at temperatures over 1000°C.

Bamboo charcoal is well known about its high porosity, which makes bamboo charcoal has excellent absorption properties. So it often be used in water purifying and harmful gas absorption. Nevertheless, it also be used in food for years. This site illustrates a Japanese cookie coated by bamboo charcoal. It also said bamboo charcoal can absorb and neutralize many poisons and toxins when ingested. However, I'm worry about that some carcinogens would be ingested too, since some carcinogens may be produced during
the scorching process.

Thus my question is what is the Toxicological result of bamboo charcoal? Is it safe? Or probably carcinogenic?

Answer 1

According to "Safety assessment of dietary bamboo charcoal powder: A 90-day subchronic oral toxicity and mutagenicity studies" Food and Chemical Toxicity vol. 75, pages 50-57.

In summary, no BCP[bamboo charcoal powder]-related systemic or general toxicity was induced by the 90-day subchronic oral exposure in SD rats, and BCP did not reveal any mutagenicity in the genotoxicity assays. Results of these in vivo oral toxicity and in vivo/in vitro genotoxicity studies support the existing theoretical weight-of-evidence for dietary safety of vegetable carbon black. ... Data from the present study suggest that BCP should be of no toxicological concern by oral ingestion, and consumption of BCP as a food ingredient and additive is safe at present use levels.

On the other hand, looking at the data in the article itself, lead content of the charcoal was found to be 0.59 mg/kg. This is about twice the limit (0.30 mg/kg) set by the EU for lead in fish for adults, and about 30 times the limit (0.020 mg/kg) for food for children. See Maximum levels for certain contaminants.