Decontamination of explosives equipment prior to maintenance

There appears to be an increasing frequency of incidents occurring in which explosives related equipment is sent to a workshop, sometimes within populated areas, for maintenance work to be carried out while the equipment remains contaminated with explosives or explosives ingredients.

Such equipment includes magazines, mobile manufacturing vehicles, pumps, pipework, hoses and explosives transport vehicles. In some cases the equipment involved has contained hundreds of kilograms and even tonnes of emulsion products, and hot work has been involved in the maintenance work carried out.

Reasons for such unacceptable practices can be put down to one or more of:

• complacency
• lack of education/training
• insufficient information on, or lack of appreciation of, the hazards
• convenience
• lack of supervision of existing procedures.

Situations have occurred where a part has needed work and, rather than detach and decontaminate the part at a 'safe' location, the vehicle has been taken to the workshop and left to the workshop staff to address.

In general, workshop staff are not aware of explosive hazards and workshops are not controlled areas free from cutting, welding, grinding or similar activities.

Further, there appears to be a perception that emulsions, precursors, ammonium nitrate emulsions, or any other name used to describe the emulsion ingredients of explosives, are inert or unreactive, cannot explode and hence are not dangerous. Such a perception is incorrect and cannot be supported by the facts. Emulsions have exploded in past incidents and their potential to cause death or injury remains. Reclassifying the emulsion from a Class 1 (explosive) product to a Class 5.1 (oxidising agent) for transport purposes does not eliminate the explosive potential of the product.

Recommendation

1. It is essential that critical pieces of equipment involved in the manufacture and handling of explosives are maintained in a 'fit for use' condition through competent maintenance schedules carried out by competent persons following competent procedures.
2. It is essential that any piece of explosives related equipment subject to maintenance or modification is properly decontaminated prior to transfer to a workshop for hot and cold work.
3. A hot or cold work permit must be raised for each task and accompany the equipment.
4. Where appropriate, only the part requiring work, properly decontaminated, should be sent to the workshop rather than the complete unit.
5. Hot work procedures must be critically assessed and then closely followed and enforced.
6. Persons involved in decontamination processes must be trained in the hazards, including their recognition, and the importance and potential consequences of their activities.
7. Persons involved in maintenance activities must be instructed in any hazards and any restrictions imposed by work orders or permits.
8. Companies must ensure that any incorrect perceptions by employees about emulsions (whether Class 1 or Class 5.1) being inert on non-dangerous are quickly and effectively corrected. This applies to all levels within an organisation.
9. Companies must properly assess whether the maintenance activity requires the equipment to be taken to a general workshop in a built-up area.

Authorised by Robert Sheridan - Chief Inspector of Explosives

Contact: Manager, Explosives Licensing , +61 7 3199 8057 explosives@dnrm.qld.gov.au

Issued by Queensland Department of Natural Resources and Mines