Wood, coke, and coconut-shell charcoals were evaluated for fluorine entrapment. The coconut-shell charcoal produced the smallest amount of solid and liquid reaction products. Efficient removal of fluorine was accomplished by the coconut-shell charcoal in a 5-in.-diameter reactor with a feed containing 25% fluorine at flow rates from 100 to 400 scfh and reactor-wall temperatures of 1200 to 1800 deg F. (C.J.G.)