BS 6643-2:1985(2010) Recharging fire extinguishers — (manufactured to BS 5423 "Specification for portable fire extinguishers") — Part 2 : Specification for powder refill charges
2015BS 5306-9:2015 Fire extinguishing installations and equipment on premises. Recharging of portable fire extinguishers. Code of practice
1985BS 6643-2:1985 Recharging fire extinguishers (manufactured to BS 5423 'Specification for portable fire extinguishers') - Specification for powder refill charges