One of the most frequently asked questions the association receives is 'How should I be storing stage pyrotechnics?'
Whether you are a theatre or other entertainment venue or theatrical supplier, as far as the law is concerned, all pyrotechnic devices are one of four Hazard Types (HT) and these are defined in Regulation 2 of the Manufacture and Storage of Explosives Regulations 2005 (MSER). Which HT a particular device is must be determined by the person storing it or by the manufacturer.
There is a scheme for officially testing and classifying stage pyrotechnics but this is for transport and it uses a different set of criteria to those for HT purposes. This scheme gives a device a classification under the United Nations – Dangerous Goods by Road (UN/ADR) system which assigns each device a Hazard Division (HD).
Although both HT and HD run from number 1 (highest hazard) to 4 (lowest hazard) you cannot simply say that a UN HD 4 device, as classified for transport, is a HT 4 device as classified for storage.
Without knowing what HT you are storing you cannot know how much you are allowed to store.
The Approved Code of Practice for MSER goes some way towards helping us though. In Annex 1 it says...
"Determining Hazard Type
For those explosives being kept as packaged for carriage, and that have been classified, there will generally be a direct correlation between the UN Hazard Division assigned them on classification for transport and the Hazard Type they should be allocated for manufacture and storage i.e.:
UN HD 1.1 = HT1
UN HD 1.2 = HT2
UN HD 1.3 = HT3
UN HD 1.4 = HT4
However, the classification is assigned to the explosives as they are packaged for transport according to the UN Recommendations, and the nature of packaging (or lack of it, and the quantity and arrangement in storage) can have a significant affect on the hazard presented in non transport situations. Therefore an assessment must be made of the hazards presented by explosives throughout the course of their manufacture, storage and handling to ensure that the correct Hazard Type is used under all conditions."
So it looks as though as long as we store it as it's packed for transport in sensible quantities then we can use the transport classification for storage purposes.
In the past people have tended to keep stage pyrotechnics in metal cupboards but this might not be the best way anymore. Remember, we are concerned with the total hazard that stored stage pyrotechnics presents. So what might happen if we store it in metal cupboards?
The Approved Code of Practice for MSER, in recommendation 264, says 'other safety precautions will include :- (a) ensuring that confinement does not increase hazard...’
The issue is that placing devices into a confined metal storage unit may increase the total hazard as there will be a chance that in the event of an explosion a significant amount of shrapnel may be generated. The act of confinement may increase the HT of your stored devices from a manageable '4' to a more problematic '3' or worse. Consider the guidance to the Fire Service that 'Fires that have spread to buildings or areas holding Hazard Type 1, Hazard Type 2 or Hazard Type 3 explosives must not be fought.'
At present, our advice is to store your stage pyrotechnics in the same shipping boxes as it was shipped to you in. You should then store these boxes in a secure location, away from the public and any escape routes. In this respect stage pyrotechnics are no different to any solvents that you may store although you should not store stage pyrotechnics with solvents
The location and amounts of any stage pyrotechnics should be recorded as part of your normal COSHH and Fire Risk Assessment procedures.
Association of Stage Pyrotechnicians