Accidental Explosions and National Security

Accidental explosions

Although relatively stable in isolation and when handled and stored carefully, ammonium nitrate will support combustion initiated in another material.  Its oxidising quality will intensify a fire, even in the absence of air.  When subjected to sufficient heat, ammonium nitrate becomes molten, extremely sensitive to impact, and will detonate readily.  Ammonium nitrate does not need to be mixed with fuel oil to detonate, as demonstrated by the following major accidents:

• In 1921 in Krieweld, central Europe, 30 tons of ammonium nitrate in two rail cars had turned into solid blocks. In order to break these blocks apart, a 100-gram cartridge of mine explosive was fired into them.  The rail cars exploded, killing 19 people;
• In 1921 in Germany, the town of Oppau was levelled and 500 people were killed when 450 tons of ammonium nitrate blended with ammonium sulphate exploded at the BASF manufacturing plant;
• In 1942 in Belgium, several hundred people were killed at a fertilizer plant when a cartridge was fired into 150 tons of ammonium nitrate;
• In 1947 in Texas City, USA, 576 people were killed when two ships carrying ammonium nitrate caught fire and exploded;
• In 1974 in Taroom, Queensland, 2 tonnes of ammonium nitrate on a truck caught fire and exploded, killing three people; and
• In 2001 in Toulouse, France, 30 people were killed and 2,242 injured when 400 tonnes of ammonium nitrate at the AZF fertilizer factory exploded. 
  

Security Concerns

Ammonium nitrate is a highly attractive material for terrorist bomb-makers.  It is effective and can be acquired without drawing attention to the terrorists or their plans.

The best known example of this was the bombing of the Alfred P Murrah building in Oklahoma City in 1995, destroying the nine storey office block, killing 68 people and injuring over 500 more.  Approximately two tonnes of ammonium nitrate was used in that bomb.

Ammonium nitrate was also used in the IRA’s 1996 bombing of London’s Canary Wharf.  Total damage was estimated at £85m and several buildings had to be demolished.  Two people were killed and 100 injured, the low casualty count due to a series of IRA coded warnings which gave police an hour to evacuate the area. Ammonium nitrate was also used in the 1998 Omagh bombing which killed 29 and injured 330 people.  Media reporting suggests that ammonium nitrate was used in the Morocco bombings of 16 May 2003, and media reports also suggest ammonium nitrate was also used in the suicide car bombings of the Istanbul synagogues on 15 November 2003, killing 24 people and injuring 300.