... human beings. The bamboo charcoal is made from 4 years old bamboo, refined through a high temperature of 1200 degrees, ... need 30 minutes per section.3. 8-15 years old children must use with adult supervision for no more than ... 15 minutes.4. Under 50 years old, OK to use it every other day for 14 ... before starting the 14 treatment cycle. Over 50 years old, OK to use it every three days for 14 ...