Burning wet charcoal is dangerous because it can produce toxic carbon monoxide fumes. When charcoal absorbs moisture, it does not burn cleanly or efficiently. Using wet charcoal grills or indoor spaces, releases increased levels of carbon monoxide, which is odorless, colorless, and highly poisonous. Never use charcoal that feels moist, crumbles easily, or has been soaked by rain or water. Only burn dry charcoal in well-ventilated areas.