Posted By Mohammed Hi there, Anyone could help me in finding out whether or not cellular phones have really been proved to be a potential ignition source in a gaseous environment. Your help is much appreciated.

Posted By Simon Birks HI, Shell Petroleum has issued guidance on this over 3 specific incidents overseas, although the UKPIA says there are no substantiated evidence. Apart from our IS Radios, we have 2 IS safe mobile phones in our company both on different networks(Atex Zone iib approved, see http://www.rexelsenate.c...sHap/pdf_ems/15_ecom.pdf). They cost a lot of money, but if that’s what you need for the zone you are working in then its what you might need to consider. Gussy

Posted By Adam Worth Oh and of course the most important factor! You say gaseous environment a few qus, What's the ignition threshold of the gas? How often is the gas likely to be within it's explosive limits? What mitigation factors exist to prevent the presence of such atmospheres?

Posted By Ian Waldram Most unlikely to be a static charge from the phone itself! Possibly a charge from the person who was insulated from the ground by wearing rubber-soled footwear, and generated static by moving in a very dry atmosphere. Then, when the driver approached the nozzle to stop the filling (on automatic, as is typical in US, so maybe Saudi too?) the static from his person discharged in the same area as fuel vapour was coming out of the fill point. In theory, a phone could ignite the vapour, but a series of events have to occur - vapour in the flammable range (quite a small volume round the fill point, then it dilutes below the LFL); the phone has to be in this area for long enough for the vapour to diffuse into the electrics; then a spark has to occur - as noted by others one obvious way is to remove the battery without switching off, if that leads to a spark with enough ignition energy. The fact that so few events have been recorded worldwide, and some of them are doubtful, shows the overall probability is very low - when you consider how many phones there are now, and how many petrol vehicles are filled each day! So the basic precaution is not to use your phone while filling, just the same as not smoking while doing that. Many people are now self-disciplined enough to let it ring if they are driving, and take the message when stopped. So just do the same when filling - even if it's in your pocket, I can't believe fuel vapour could diffuse into your clothing at flammable concentration and get into the phone as well, in the time available. If you leave it inside the vehicle - even safer!

Posted By Adam Worth Static is a well known route for ignition of petrol vapour There are several cases of this occurring, mainly from countries where you can 'lock on' the nozzle and sit in or leave the car whilst it fills. In the UK we tend to hold the nozzle and stay at the same potential I think that proves the point :) I always wonder why they don't ban cars from petrol stations as that would eliminate another source of ignition :)

Posted By 9-Ship For those of you with access to Barbour index, if you search with similar wording to this thread title, you should come across a BP document regarding electrical ignition risks etc. this very topic is discussed, and is largely dismissed because of the fact that the MIE (Minimum Ignition Energy)of petrol vapour is too high for a mobilephone to cause problems. One of the key conclusions is that the main risk from mobile phones is one of distraction by the user while filling up with petrol - they are so busy talking that they fail to realise that the petrol tank is about to over flow and an amount of fuel spills out and can then run on to the hot exhaust etc and up she goes!! There is also the risk from static built up from the human body and clothing. By and large, I think this risk is just about a complete myth. It just might happen in a, say hydrogen rich atmosphere (or methane) because they have far lower Minimum Ignition Energies). I think in the final analysis, no one is brave enough to say there is no problem with mobile phones on petrol forecourts. For a while I worked around aircraft - there was never any issue of nearby transmitting aircraft causing problems while other aircraft were being refuelled - I accept there may be an issue with different radio frequencies etc - but such a radio has a higher wattage out put than a mobile phone.