An explosion occurred at a building used to store fertilizer and agricultural chemicals, injuring 20 people. An investigation found that welding work being done near where ammonium nitrate and sodium chlorate were stored likely caused a small fire that led to a series of explosions. It is recommended that safety measures be implemented, such as ensuring chemicals are properly stored and ventilated, conducting inspections for spills, and assessing risks before maintenance work involving heat such as welding. Sodium chlorate specifically requires controls on mixing, heating exposure, and storage to prevent combustion.

1. DOSH
Fertilizer and agrochemicals
Name : Ann

2. Definition & History of it.
An explosion occurred in a building used for storing fertilizer and
agrochemicals - herbicides, insecticides, pesticides and fungicides.
The impact of the explosion had brought down the building,
causing massive damage to adjacent buildings, shattered glass
and door panels on many nearby premises within a distance of
400-500 meter radius. 20 people including four children were
injured and they mostly received outpatient treatment. The
building is used to store fertilizer and agricultural chemicals.
Investigation shows that before the incident, there were welding
works being carried out to install extra racks adjacent to where
Sodium Chlorate and Ammonium Nitrate were stacked. It is
believed that a small fire started from the hot work activity and
eventually led to a series of explosions.

3. Following this event, it is recommended that the following
safety measures are taken:-
• Ensure building used as fertilizer or agrochemicals storage is well ventilated to
mitigate any gaseous substance, and airborne dusts.
• Housekeeping should be maintained and materials are arranged in a
systematic manner. It is recommended to clean the dust via suitable vacuum
cleaner that is specially designed for that particular industry and efficient
enough for the said purposes. This would ensure minimal airborne of
agrochemical dust within the compound.
• To prevent spillage and contamination, make sure that the bags have been
completely sealed on filling, are made of a material that is impermeable to
water or oil, and are strong enough to withstand any damage during normal
storage, handling and conveyance.
• Conduct routine checking and inspection for the purpose of detecting any
spillage and immediately clean up any spillage found on any surfaces - floors,
walls, etc.

4. • Ensure that bags of ammonium nitrate have been removed from the
immediate area and contaminated items have been thoroughly washed to
remove ammonium nitrate before allowing any maintenance work that
involves heat such as welding or cutting to start.
• Sodium chlorate is a strong oxidizing agent. However the compound is not
intrinsically dangerous. The danger arises if:
– they are allowed to mix intimately with potential fuels, including materials
such as paper, sawdust and sugars;
– they are stored in such a way that they can become exposed to
vigorous external heating in a fire situation;
– they are allowed to mix with acids or certain other chemicals.

5. Therefore, storage requirement of sodium chlorate and hot work activity
consideration should consider the above issues.
• Wooden pallets should not be used for the routine storage of sodium
chlorates since, in addition to being a combustible material, they may,
with continued use, become impregnated with chlorate and thereby
themselves become a considerable fire risk and also a potential source of
ignition. Any wooden pallets which are suspected of being contaminated
with chlorate can be destroyed by burning under controlled conditions in
an isolated area.
• To conduct risk assessment before carrying out any renovation work that
involves welding or electrical works.
• Ensure information, instruction, guidance and training as well as effective
supervision is given to operators or employees who conduct loading or
unloading activities and any non routine activities such as welding and
electrical works.

6. END