Calcium Hypochlorite – frequently asked questions 27 June 2011 No.11-007 We refer to our Special Circular No. 99-021 dated 6 December 1999 and No. 00-011 dated 21 September 2000. International Group of P&I Clubs wish to raise awareness in the maritime industry of the hazards and precautions associated with the carriage of calcium hypochlorite through the following FAQ's. 1 What is calcium hypochlorite? This chemical is a white or yellowish solid that is soluble in water. There are several products manufactured as water purification and bleaching agents, which contain calcium hypochlorite (CH) as their active ingredient. The three most common products are twohigh strength types (UN1748 and UN 2880) and a lower strength type, often referred to as bleaching powder (UN2208). The entries in the IMDG CODE are shown as follows: Class 5.1 UN 1748 Calcium hypochlorite dry, or calcium hypochlorite mixtures, dry containing more than 39% active chlorine; Class 5.1 UN 2880 Calcium hypochlorite hydrated, or calcium hypochlorite hydrated mixture containing not less than 5.5% but not more than 16% water; Class 5.1 UN 2208 Calcium hypochlorite mixture dry containing more than 10% active chlorine but not more than 39% active chlorine. The following are additional to the above and are included in the Amendment 35 to the IMDG Code which is on a voluntary basis from 1st January 2011 and mandatory from 1st January 2012: Class 5.1/8 UN 3485 Calcium hypochlorite, dry, corrosive or calcium hypochlorite mixture, dry, corrosive with more than 39% available chlorine (8.8% available oxygen) Class 5.1/8 UN 3486 Calcium hypochlorite mixture, dry corrosive with more than 10% but not more than 39% available chlorine Class 5.1/8 UN 3487 Calcium hypochlorite, hydrated, corrosive or calcium hypochlorite, hydrated mixture, corrosive with not less than 5.5% but not more than 16% water Calcium hypochlorite or calcium hypochlorite mixtures should be transported in accordance with the requirements set