Ipad in Explosives Magazines

Following on from my question on Explosive Magazine Stock Control software, are you allowed to use an iPad inside an explosives magazines in Europe and if not what are you allowed to use?

17 answers

  1. Answered by Ian McKay

    There is easy no yes/no answer. The use of any electrical equipment in a magazine in which explosives are present should be covered by a risk assessment which itself will support whatever local laws or rules there are. So, if on a particular site the rules say, “No electrical items in magazines” then the answer is “No”.
    If the rules allow it, then the use of an iPad or similar device must be based on the hazard – if any – which it poses to the stored explosives based on how sensitive they are to such stimuli as stray currents, magnetic fields etc.

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  2. Answered by andy pettitt

    I am aware that in Norway at a specific facility employees are free to listen to ipods in explosives working area – so same thing. Dependent on what is stored in the magazine and subject to a thorough risk assessment highlighted by Ian Mckay. Any kit used for scanning for Track and Trace compliance also falls into this bracket ?

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  3. Answered by Phil Robinson

    Anthony,
    Ian is correct in his answer in that the issue is addressed by risk assessment.
    Bear in mind that the equipment may have electrical contacts (for charging or for input output ports) which are exposed. The screen will also become contaminated by explosives residues as it is a touch screen device. To extend to normal laptops for anyone else considering this option- they have fans that will suck in the atmosphere in a store, including dust (explosive or otherwise).
    I would recommend that the equipment should be IP65 rated at least.
    Andy the Ontaris kit is suitable for inside explosives stores – it was designed with quarrying companies.

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  4. Answered by Mark Ribbands

    From a practical point of view I’m sure it’s fine;
    Just use common sense: don’t wrap detonator wires round the thing, or attempt to check it onto a commercial flight immediately after …

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  5. Answered by Tony Slate

    The key issue is really is this piece of equipment compatible with the explosives and any explosives atmosphere that is encountered in the store. The sensitivity of the materials in store to stimulation by the electric or electro-magnetic components of the ipad should be fully assessed.

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  6. Answered by Jamie Adam

    I agree that it would depend on the type of explosives stored and any local legislation or restrictions.

    The most important thing would be to ensure that the iPad does not transmit a signal, either Wi-Fi or GSM (GSM-capable iPads are likely asking for trouble), so the iPad definitely should be in ‘Aircraft’ mode, and there should be strict protocols for checking this.

    To mitigate problems further, I’d also recommend a hard case to protect the iPad from explosives residue, which can be kept at or near the store for just that purpose. If you really wanted to be safe, I guess a case with a micro mesh incorporated to act as a form of Faraday cage would further reduce the risk of stray currents. You’re then left with potential electrostatic discharge as you use the iPad screen, which can be removed in the usual ways.

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  7. Answered by Anthony Grizaard

    Thanks for the answers so far, we are already doing a risk assessment, our regulations are a bit vague on this issue as well so just wondering what you do in Europe.

    We do not store any electric dets and only use nonel type down holes and surface, boosters and a bit of cord non of which are susceptible to electronic emissions from iPad (ok we have to take care with nonel tube and static). We are probably going to trial electronic type dets in the future and will review use of the iPad when we do so.

    Good point as well about WIFI Jamie, would not use a WIFI enabled iPad. We have a little office in our magazine compound and would store the unit in there, not in the magazines.

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  8. Answered by Phil Robinson

    Anthony, I am surmising that you intend inputting all movements in and out of your store into some computer software. Given that id numbers have to be recorded according to EU and GB legislation this would become very tedious for anything but very small numbers of items. Most systems in Europe use a scanner to read the bar codes. If you have registered the xml file from your supplier within the software this can be used to link to product names and quantities via the scanned bar codes. Scanners are usually Bluetooth linked to the tablet for this operation. The risk of your products being accidentally initiated by the low power Bluetooth radio which operates in the GHz range of frequencies is almost negligible.
    Be also aware of PETN dust from the detonating cord in your risk assessment of accidental initiation. Electronic detonators have a low risk of accidental initiation by radio transmission. The most likely scenario is a radio transmission can interfere with the programming phase of the use of these detonators after they have been loaded into holes – this is more likely from your site radios that are used by the shotfirer. You would not be using the tablet computer at this time as you will have already registered the id codes by this point and it would be turned off.

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  9. Answered by Mark Ribbands

    This is one of the bees in my bonnet: I think there’s an awful lot of rubbish talked about the accidental initiation of electro explosive devices by radio transmitters. The RF output of a Wi-fi and GSM-enabled iPad is so trivial that it may be disregarded.

    Unfortunately a lot of this stuff has got into the literature and is now quoted all over the place without consideration of real risks.

    Sure, if detonator wires are unwound, and extended as a perfect dipole antenna, or a large electric detonator circuit forms a giant aerial on the ground, then you blast the area with hundreds of watts from an HF set, or powerful microwave radars, then maybe; but devices as stored, with coiled wires, and piddly little hand-held transmitters? No way. It’s nonsense.

    Remember that we live surrounded by electromagnetic radiation all the time: the commercial radio mast up the road might well be providing more RF field strength that your iPad, and dets don’t keep going off in your hand, do they?

    Please don’t think I’m confusing this with stray currents, as that’s very different. I am certainly very uncomfortable using EEDs if there are overhead HV wires about, or an electric storm threatens.

    As always, it’s important not to be distracted from real risks by imagined ones.

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  10. Answered by Nigel TAYLOR MIExpE

    I believe most of you are on the right lines – all that I would add is that Electric lighting systems in explosives stores MUST be deemed to be “Inherintly Safe”
    All metal surfaces other than non ferrous ,must be painted or taped over

    One then has to ask about the wisdom of an electrical device introduced into an explosives store, especially as my ancient memory recalls something on this line in the good old and now deceased “Green Book – Guide to the Explosives Act 1875-Explosives Act 1923.
    Whilst I accept virtually all of the Green book was thrown out with the bath water
    P162 (m) talks of allowing artifical light into a carriage or boat containing explosives – though it doesn’t mention Store!
    What I am trying to suggest , and I am not doing it very well, is that I suspect that much hypothetical and apocryphal credit has been attached to issues claiming them as fact when in fact when examined are not in reality fact.!!
    Certainly common sense should decree that any unshielded device capable of emiting RF or electro mechanical signal. Should NOT be used in an explosives magazine.

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    • Mark Ribbands

      Hi Nigel: I too have fond memories of the ‘Green Book’ (That’s the Explosives Act 1875 to the younglings).

      All that stuff about painting exposed ferrous metals – with cork chips mixed goodly and thick – and so on, and the fetish about rubber footwear was nothing to do with RF, for the unassailable reason that portable radios hadn’t yet been invented.

      It was (is) all about not creating sparks inside a magazine. That’s still a good idea, but remember when the 1875 Act was first written it was almost exclusively about gunpowder. I agree that avoiding sparks in a BP mag is a spectacularly good idea. But again all this obsession with not having an exposed screw head in, for example, a modern store full of metal ammo cans containing HE ammunition or SAA, persists.

      And much of the Green Book’s reference to ‘artificial light’ meant oil lamps, or candles on miners’ hats!

      Inherently safe electrical installations? Good idea, but again nothing to do with RF. A halogen or metal halide lamp which bursts on failure and showers hot glass everywhere (I’ve seen both) would indeed be unfortunate. As would a cheap switch which sparks on operation and is open to atmosphere.

      But the latter is more important in places where there are explosive atmospheres (eg flammable gas, hydrocarbon vapour, fine dusts.)

      And once again there is often confusion. In this case between ‘explosive atmospheres’ and bulk, non-dusty explosives kept in boxes. Time and again I have had such exchanges of views with enforcing authorities, many of whom have read all the books, but don’t understand WHY the regulations are there, and therefore can’t sensibly use discretion based on actual experience of practical situations.

      I have on one occasion been forced to abandon safe practice because it was deemed technically non-compliant, replacing it with something which was potentially dangerous, but which was compliant. So that’s OK then.

      Hi Phil – you mention PETN dust from det cord. Are you sure? I have never used a PETN cord which has any possibility of creating airborne dust, no matter how roughly it was cut and shaken about (and competent operators wouldn’t do that anyway).

      Dry PETN powder is way too sensitive to be loaded loose into anything. PETN cord includes a considerable amount of wax desensitiser for safety, which has the secondary effect of causing any spilled powder to clump up and fall to the floor. And no one should be unpacking or cutting cord anywhere near a magazine anyway.

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  11. Answered by Ron Scott

    The use of any electrical device in a magazine can initiate the most sensitive EEDs. All equipment has to be marked with a CE mark that requires all equipment to conform to BSEN standards for that type of equipment. This in turn specifies the radiated and conducted emissions from the device and can only be so marked if it has been tested to show compliance and the results are available and verified by the responsible person. From this information the effects of these emissions can be determined for any detonator used in the facility and a suitable safety margin established. Similarly the effects of nearby rf transmitters can be established. OFCOM should be able to provide details of all transmitters within say a 10km radius.
    The above is how I determined the safety of electrical equipment and transmitters for the magazines that I was responsible for safety.

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    • Mark Ribbands

      > ‘The use of any electrical device in a magazine can initiate the most sensitive EEDs.’
      Hmm.
      I feel a gentlemens’ wager coming on. I’ll put a bottle of Bollinger on you showing this happen, at the next AGM.
      You bring the ‘most sensitive’ EED, I’ll bring a 5 watt UHF radio, which may be placed, on transmit, anywhere you wish.
      Game on? 🙂
      The serious point I’m making is that ‘compliance with regulations’: this Standard – that Mark – and so on – often has no basis in practical reality.
      It matters because sometimes over-zealous enforcement of regulations, often without true understanding, can lead to a reduction in safety.

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  12. Answered by Phil Robinson

    Gentlemen Anthony does not have any standard electric detonators in his store. I am with Mark Ribbands on the likelihood of initiating standard electric detonators by RADIO transmitters. The more relevant document on that subject is BS6657 Guide to the inadvertant initiation of electroexplosive devices. My comment on petn dust was to do with potential contamination drawn into fans on laptops. I agree that most cords have crystalline PETN. Some of the low core load cords have a fine structure.
    Detonator wires in storage are wound in a non-inductive manner. If Electronic detonators are in the store, their construction is such that there is no direct connection to a fusehead inside the detonator with the external wires.

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  13. Answered by Kenneth Cross

    Anthony,
    Given that you are already in the process of making a Risk Assessment, you might want to include some accepted practice (UK MOD), Chapter 24 of JSP482, which is published at https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/605759/20150723-JSP_482_Chapter_24-O.pdf
    Table 1 gives the WOME (Weapons, Ordnance, Munitions and Explosives) Categories applicable to the management of electromagnetic radiation in and around explosives facilities.
    Annex B, Tables give Common Transmitter Minimum Safe Distances.
    For the interest of all, the minimum proximity of a 100mW, 2.4GHz,Bluetooth transmitter to WOME ranges from 0.01m to 0.15m, depending on how you categorise the WOME.
    At the end of the day, it’s going to be your call, in agreement with your regulator.

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  14. Answered by David Graham-Battersby

    If I may point out the need for assessing the risk. The Likelihood will be based on many and varied factors which have been discussed. The consequences needs to be understood equally well. I will make the point of why it needs to be done. The advantages and disadvantages of the risk over time need to be understood. Essentially I am asking is it really necessary and how does it improve or enhance the processes to a measure that is worth keeping. I am reminded of the story of NASA who enterprisingly invented a pen that could be used in space; so told the Soviets of their ingenuity. The Soviets replied we use pencils. Here the “so what” is not the risk which clearly can be dealt with, but what advantage is gained by using it compared to not and is that worth any risks.

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  15. Answered by Anthony Grizaard

    Thanks everyone for your helpful answers!

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