Calcium Hypochlorite

June 1999

The following is a copy of the Club’s August 1998 circular.

TO THE MEMBERS

Dear Sirs,

CALCIUM HYPOCHLORITE (HYDRATED) UN 2880

The Association has been advised by Dr. J.H. Burgoyne & Partners that they are undertaking research to determine the critical ignition temperature of the hydrated form of high strength calcium hypochlorite UN 2880. The critical ignition temperature is the temperature at which a run away reaction begins, often followed by fire and/or explosion. Dr. J.H. Burgoyne & Partners advise that their work to date has given rise to the following serious causes for concern:

i. The International Maritime Dangerous Goods Code page 5138 under Stowage states:

"Away from sources of heat where temperatures in excess of 55ºC for a period of 24 hours or more will be encountered."

J.H. Burgoyne & Partners advise:

"Preliminary results of the research indicate that for the type and size of packaging used routinely to ship this material around the world, the temperature at which the run away reaction is likely to begin is much lower than that recommended by the IMO".

ii. Dr. J.H. Burgoyne & Partners further advise:

"It is our understanding that the ambient temperatures of holds of certain container ships can reach the critical ignition temperature of this material, which preliminary results of our research suggest is considerably lower than that previously published. Accordingly, it is suggested that this material is not shipped in the holds of such ships and that stowage on deck is arranged to avoid the heating of this material by direct sunlight."

This advice is contrary to the provisions of IMDGC which allocates category A status to calcium hypochlorite (hydrated); stowage category A permits stowage on deck or under deck.

As soon as the Association has any further information it will be passed on to the Members.

Yours faithfully,

 

Since this circular was issued there have been several publicised cases concerning the transportation of this cargo. Members carrying this cargo are advised to take considerable care and, if in doubt, to contact the association for advice.

Click here to see November 1999 circular on this subject