Bleaching powder


A white powder with a strong chlorine odour, shipped in drums.

Contamination by inorganic acids, organic substances and other oxidizable materials can bring about rapid decomposition. Localised heating occurs where contacted by the contaminant and where enough heat is evolved to reach the flash point of the contaminant a fire will follow. Calcium Hypochlorite heated above 100°C will decompose rapidly.

A closed drum subject to excessive heat may blow off the lid or rupture. Is poisonous, and in confined stowage, holed or non-airtight drums may give off chlorine gas which will destroy any textile fabric and tarnish metals. If unsuitably packed or exposed to air through breakage of containers the commodity will also deteriorate rapidly due to the action of carbon dioxide and moisture and develop into a substance having little or no bleaching power. The powder will also lose its strength if stored for long periods. Corrosion of the drums is also rapid unless perfectly airtight. The corrosive action has been known to occur to drums during a voyage of no more than three weeks duration.

Shortage may be due to two causes:

  • Splitting of the seams and loosening of lids due to knocks, blows or a fall in transit, and subsequent leakage.
  • Corrosive nature of contents on steel and iron, resulting in holing of drums or los\osening of lids, and subsequent leakage.

Reference is made to the relevant IMO regulations of hazardous cargo.