Poona

On 15 July 1971, the Danish tanker Poona was in the port of Gothenburg (Sweden) loaded with drums containing 36 tonnes of sodium chlorate and 600 tonnes of rapeseed oil. Heavy steel structures were to be hoisted by a crane into the hold where the two chemical substances were already stored. One structure started to swing and thereby punctured a drum of rapeseed oil so that the content ran out. At the end of the loading process, a drum of sodium chlorate was damaged and it mixed with the rapeseed oil. Structures slid on the floor, creating sparks that ignited the mixture. Flames flared up out of the hold and 3 severe and rapid explosions occurred.

Fire fighting was very difficult and dangerous due to the ferocity of the fire and to the fact that the ship also contained hydrocarbons. The fire was only fully extinguished after 10 days. In this accident, 3 sailors were killed and 6 injured.

It is highly inappropriate to stow an oxidizer (sodium chlorate) and a combustible (rapeseed oil) in the same hold: Sodium chlorate is a powerful oxidizer that reacted violently with rapeseed oil, making a flammable and explosive mixture. Because of the heat of the fire, the sodium chlorate was decomposed to free oxygen, which is an exothermic and explosive chemical reaction.

Sources:

- HELCOM, 2002, HELCOM Response Manual - Volume 2
- HOOKE, Norman, 1997, Maritime Casualties 1963-1996, second edition, LLP Limited, Londres