Keywords: Ammonium nitrate, Toxic fume, Accidental fires, NOx production, Storage risk assessment.

Ammonium nitrate (AN) may decompose to give toxic gaseous oxides of nitrogen when involved in fires. This paper reports measurements of the rate of fume production during fires of the type which might occur in storage conditions.

Two types of experiment have been carried out. In the first type AN is heated by thermal radiation by flames from a separate fire. The second type of test involves measuring the reaction, during a fire, between packaged AN and the timber palleting on which it is usually stored.

The results can be used as the basis for a risk assessment of fume production from AN storage sites. The approach taken by the UK regulatory authority, the Health and Safety Executive (HSE), to such risk assessments is outlined.

Dr Graham Atkinson, Health & Safety Executive, Health & Safety Laboratory, Buxton, UK.
WD Adams, Health & Safety Executive, Merton House, Bootle, Merseyside, UK.

23 pages, 10 figures, 1 table, 10 references.