Cell phones causing explosions. Is it true? - Page 1
Forum section: electronics / beginners

author: sainbablo
author_rank: Regular Contributor
timestamp: December 09, 2016, 05:07:29 pm
content: An SMS warns that receiving calls on cell in kitchen near vicinity of gas burner may cause explosion.Says to maintain distance of about 10-12 feet while switching the cell on.Even micro ovens or induction ovens may be dangerous. No further details are provided.Is this true???

author: Cliff Matthews
author_rank: Unknown
timestamp: December 09, 2016, 05:17:41 pm
content: A myth propagated long ago - pay no attention to such non-sense. Cell phones have no incendiary effects.www.snopes.comhas a lot a answers at this level.

author: Cliff Matthews
author_rank: Unknown
timestamp: December 09, 2016, 05:20:51 pm
content: ..couldn't think where I'd heard that one before, but this one's good:http://www.snopes.com/autos/hazards/gasvapor.asp

author: Neilm
author_rank: Super Contributor
timestamp: December 09, 2016, 05:24:13 pm
content: Mythbusters did that with all sorts of explosive atmosphears, first off with petrol vapours. Never got it to go bang.

author: sainbablo
author_rank: Regular Contributor
timestamp: December 09, 2016, 05:42:23 pm
content: Quote from: Cliff Matthews on December 09, 2016, 05:17:41 pmThe SMS being unsubstantiated made me suspect an ulterior motive behind it.An attempt to increase neurosis in vulnerable individuals with lowered thresholdto rumors?

author: TimFox
author_rank: Super Contributor
timestamp: December 10, 2016, 05:33:33 pm
content: Facts are for losers. Modern people only believe in what they feel is correct.

author: rfeecs
author_rank: Frequent Contributor
timestamp: December 10, 2016, 07:10:41 pm
content: I remember it from one of my first cell phone manuals.http://www.motorola.com/mdirect/manuals/StarTAC3000_User_Manual_E.pdfFrom the Motorola Star Tac manual:Quote

author: Tomorokoshi
author_rank: Super Contributor
timestamp: December 10, 2016, 08:52:16 pm
content: Quote from: Cliff Matthews on December 09, 2016, 05:17:41 pmUnless one happens to have a Samsung Note 7.Regarding the notice by Motorola just above, it's understandable that at when cell phones first came out Motorola would put a warning like that in the manual. That's because Motorola sold, and still sells, high-power 2-way radios that are used in all sorts of industrial areas where there could be hazardous concentrations of gas vapor. Those radios would have a similar warning.The point being is that it isn't the radio operating properly that is the reason for the warning. It's the case where a component in the radio fails, leading to spark or thermal ignition of the gas vapor. The way out of that is to have a radio designed and built to be intrinsically safe in those locations. Not a cheap device.Anyway, when people started to get cell phones the potential for failure remained. These warnings aren't really about the neighborhood gas station. It's about places like chemical plants or places that use chemicals in production.

author: IanB
author_rank: Super Contributor
timestamp: December 10, 2016, 08:54:11 pm
content: A naked flame near to a gas burner is a really bad idea. The gas might catch fire and start burning.

author: cravenhaven
author_rank: Contributor
timestamp: December 10, 2016, 10:12:29 pm
content: All petrol stations in Australia have a warning sign to 'Not use Mobile phones while filling the vehicle'.Many years ago I was at a servo in Sydney and the driveway attendant was smoking a cigarette while filling vehicles.

author: Falcon69
author_rank: Super Contributor
timestamp: December 10, 2016, 10:45:16 pm
content: Quote from: sainbablo on December 09, 2016, 05:07:29 pmI'd be more worried about the government turning on the camera of your phone to spy on you or that camera built into your new LCD/LED TV to spy on you.

author: jonovid
author_rank: Super Contributor
timestamp: December 10, 2016, 11:58:16 pm
content: Quotesmoking is a health hazard

author: Brumby
author_rank: Unknown
timestamp: December 11, 2016, 01:11:39 am
content: Quote from: Neilm on December 09, 2016, 05:24:13 pmI saw that episode - and they didn't really put much thought into their efforts. Just a hash up and hope for the best. Heinrich Hertz would have failed in his experiments with such an approach.As I understand it, for such a scenario to become a real risk, you would need a tuned circuit (the higher the Q, the better) with a spark gap in an ideally flammable environment. Sufficient energy would need to be transmitted (pulsed transmissions would be helpful here) and enough energy harvested to create a spark. Also, the flammable environment would probably need to be somewhere close to a stoichiometric mix of fuel and oxygen (damn that nitrogen) - and being a bit on the warm side would be good. I would think that this is not impossible .... but itwouldbeextremelyunlikely.I would be interested to see someone actuallyproperly designand build such an experiment. It could even look like a radio project - just as long as a result could be shown without any power applied to the 'receiver'. Explanation could start with the old-fashioned 'crystal set' and finish by showing everyday materials displaying capacitance, inductance and antenna characteristics.What the Mythbusters did had about the same potential for success as me trying to build a DFM by randomly plugging ICs into a breadboard.Just my thoughts.

author: IanB
author_rank: Super Contributor
timestamp: December 11, 2016, 01:32:49 am
content: Quote from: Brumby on December 11, 2016, 01:11:39 amActually, no. Ignition of an explosive atmosphere is a very real danger and has been the cause of untold fatalities and other losses. The gas/air mixture absolutely does not have to be close to the stoichiometric ratio. Check this reference for illustration:https://www.mathesongas.com/pdfs/products/Lower-(LEL)-&-Upper-(UEL)-Explosive-Limits-.pdfOne recent case in the news was a misguided soul who was using hairspray to fix decorations to things in his room:http://www.bbc.com/news/uk-england-lincolnshire-37859495It is often said that to cause a fire you need fuel, oxygen and a source of ignition. But you should always assume that if an explosive atmosphere is present a source of ignition will be certain to reveal itself. Don't take chances.

author: Brumby
author_rank: Unknown
timestamp: December 11, 2016, 03:25:26 am
content: I wasn't sure about the flammable environment - so I went with stoichiometric as being the best chance for ignition from a source that was bound to be weak. Of course, I may be wrong about that.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: December 11, 2016, 04:42:57 am
content: Clearly cell phones rarely cause explosions, even though it is theoretically possible. But it is a case of unbalanced consequences. Not using the cell phone seldom has any real consequences, and extremely rarely can be the cause of injury or property damage. Using it can rarely cause damages, but those damages are likely to be very large including a very real possibility of death. Prudence suggests just leaving the cell phone off, or at least moving away. What ever the risk is it goes down as the square of the distance, so a bit of space is a wonderful thing.

author: SeanB
author_rank: Super Contributor
timestamp: December 11, 2016, 05:37:02 am
content: You just need a very low humidity atmosphere, a fast flowing fuel ( coming out of a can for example, or flowing into a fuel tank) that is non polar so it can generate a static charge on a non conductor, or an isolated conductor, that then flashes over, providing the initial spark that ignites the rest.That is why you should not fill plastic fuel containers ( or even metal ones) in the vehicle, but take them out and fill on the ground, so the static charge can leak away on the surface of the concrete. Also why car tyres are considered non insulating, as they are carbon loaded, and thus are going to be a high resistance, but still dissipate static charge, so you do not have to ground bond the car to the fuel filler in the filling station.Aircraft however require the use of a ground lead, as there the chance of a spark is the same, but the value of the damage is so much higher, plus often the floor is clean and non conducting. Thus a ground lead to keep static charge from building up and arcing across the filler nozzle, or from arcing across the connection to a pressure filler connector during insertion or removal. They also ground bond the piping reinforcement, and have extra ground wires woven into the piping as well for static control, as well as a semiconductor layer to handle charge build up. Internally the pipe sections all have ground wires to the airframe, and this is part of the maintenance to check integrity.The main pusher for not using a cell phone during refilling is that you are not going to pay attention to the task on hand, and thus can very easily spill fuel, not put the filler cap back on, forget you are filling and drive off or any number of things done distracted. If the call is so important sit in the corner and finish it, humans are incapable of multitasking well, and most are barely able to handle breathing, walking and any other single task at the same time, even if breathing is a semi autonomous process.

author: Bud
author_rank: Super Contributor
timestamp: December 11, 2016, 05:56:31 am
content: Years ago when I was in Vancouver on business, the business owner took us for a boat tour. When we stopped for fuel at a floating marine fuel station we were warned not to use cell phones while fueling the boat.

author: Zero999
author_rank: Super Contributor
timestamp: December 11, 2016, 11:39:09 am
content: Quote from: Tomorokoshi on December 10, 2016, 08:52:16 pmIt's probably just an arse covering exercise. All devices used in an explosive atmosphere need appropriate certification but a mobile phone/two way radio won't be certified so manufacturer put this kind of warning in the manual as a disclaimer.

author: bktemp
author_rank: Super Contributor
timestamp: December 11, 2016, 01:43:38 pm
content: I've heard the warnings are because of the batteries: If you drop your cell phone, the battery can fall out and generate a spark.

author: arlipscomb
author_rank: Contributor
timestamp: December 13, 2016, 02:21:56 am
content: Cell phones can emit enough RF energy to cause problems. I once had a pair of glasses that would arc around the hinge when I was talking on my cell phone. The effect was very noticeable at night. If you were to bring the phone down near the escaping vapors of the fill pipe I would believe you could get ignition.The Mythbusters show was pretty good, but they had their share of bad information.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: December 13, 2016, 02:27:47 am
content: Just do some quick estimates of the ERP that Heinrich Hertz was working with, look at how his receiver system worked and then comment on whether or not cell phones can do this.

author: Brumby
author_rank: Unknown
timestamp: December 13, 2016, 03:25:56 am
content: Quote from: arlipscomb on December 13, 2016, 02:21:56 amI call that an interesting data point ... and I would take it as 'proof of concept'.Certainly, the proximity of the handset to the glasses would help a lot - but to get not only a spark, but one that was visible, says a lot. Greater range would simply need a better tuned circuit.

author: Jeroen3
author_rank: Super Contributor
timestamp: December 13, 2016, 06:35:03 am
content: Cell phones could cause a fire at a petrol station because the attached human is distracted.

author: sainbablo
author_rank: Regular Contributor
timestamp: December 13, 2016, 04:33:13 pm
content: Quote from: Falcon69 on December 10, 2016, 10:45:16 pmQuite right. That is yet another specialised geographical hazard.

author: sainbablo
author_rank: Regular Contributor
timestamp: December 13, 2016, 04:52:16 pm
content: Quote from: CatalinaWOW on December 11, 2016, 04:42:57 amIf damages are likely to be very large then what could be cause of such death? I am digressing towards pathophysiology if I may.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: December 13, 2016, 09:42:39 pm
content: Quote from: sainbablo on December 13, 2016, 04:52:16 pmIn terms of risk assessment - an explosion/fire initiated by a cell phone induced arc would cause injury or death by one or more of the obvious mechanisms - burns, trauma (ripping, smashing or tearing of the body) or overpressure. I say very large because in the case involved there are large quantities of fuel in the vicinity. While the initial explosion may be small (and indeed may not propagate), there are numbers of opportunities for the event to cascade. Rupture of vehicle fuel tanks. Displacement of fuel hoses from fill ports. Displacement of dispensing pumps from their fuel pedestals.A large scale explosion or fire is NOT inevitable. But if a spark initiates combustion it seems to me that the odds of getting something large is not measured using large numbers of zeros. Much closer to 1 in 10 than to 1 in 10000. Fortunately the chances of getting a spark seem to be quite small, both from the evidence of experience and from thinking through the physical requirements for such a thing to happen.Injury or death by not using a cell phone has to come from some more contrived situation - say a delay in arrival of emergency services in the case of a heart attack, or not warning someone that a crazy person has sworn to kill them and is on the way. Strictly a secondary result coming from a delay in communications.So to restate the point. The consequences of caution are basically limited to a little inconvenience. The likelihood of something bad happening from using a cell phone is very low (obviously, because cell phone use during refueling and near refueling stations is widespread and resulting explosions are at most quite rare). But the potential consequences if it does happen are bad enough that a little inconvenience seems a small price to pay.

author: larrybl
author_rank: Regular Contributor
timestamp: December 14, 2016, 03:03:07 pm
content: Probably noobish but I would think that some cell phones (at least mine does) have a small electric motor for the vibration mode. I would expect there would be some slight arcing around the armature when receiving a text or call.

author: sainbablo
author_rank: Regular Contributor
timestamp: December 14, 2016, 04:40:57 pm
content: Quote from: CatalinaWOW on December 13, 2016, 09:42:39 pmCascading explains a lot.

author: sainbablo
author_rank: Regular Contributor
timestamp: December 14, 2016, 04:57:55 pm
content: Quote from: larrybl on December 14, 2016, 03:03:07 pmSome 2 decades or so ago cell phones were really bulky and heavy. Became pretty warm if used more than 8-10 minutes.Those were the days when talk about ionising radiations causing brain cancer got currency. So were the news about pace makers getting packed up causing fatal cardiac arrests. Batteries are now very slender and compact but are the cells getting less warmer?I do not know how would a person with cochlear implant react to a cheap cell. Any input?

author: ayrex
author_rank: Contributor
timestamp: December 14, 2016, 07:14:16 pm
content: I must say. I didn't read the whole thread. But as an electrical engineer who works for a technical inspection agency in Germany (mostly consulting in explosion protecting, machinery and functional safety) I've done such assessments.Using you're phone won't ignite an explosive atmosphere. You need much more energy inducted by the RF field of your phone. And a phone which could do so I won't recommend holding it near your head.BUT (and there's always a but): If you drop you're phone and the battery flys around (or even the impact shock causes a small gap between battery and phone's battery contact) there is a possibility that an explosive atmosphere could be ignited by a spark.Of course a defective LiIon battery (thermal runaway!) could also ignite (and produce) an explosive atmosphere. But a electrostatic dischage because of your fur coated seat can also ignite it.Or your car's exhaust.Why is it unlikely? Because there is no explosive atmosphere (especially no dangerous explosive atmosphere -> >10 liters of vapor-air mixture). The gas pump nozzle sucks up the most gas vapor coming out of your tank while filling it up. Only in case of a failure there could be one. (typically 20cm around the gas pump is Zone 2)Hope it helps a bit.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: December 14, 2016, 10:50:18 pm
content: Quote from: ayrex on December 14, 2016, 07:14:16 pmThere are huge swaths of the United States that do not use these protective nozzles. They are required in California and several other states, but it isn't a universal requirement. I can't say how common they are elsewhere in the world. These inconsistencies go far in explaining how various safety warnings come about. A warning that is totally in-necessary leaks in from somewhere else where it may make sense.An example I have mentioned elsewhere was a regulation making illegal to serve ice in the drinking water of workers. The origin of this rule was from a century ago in a northern part of the US where most ice was sawn from lakes, and often was contaminated with animal urine. Made sense where it started. Didn't make sense in a sun belt state that had long since given up shipping sawn ice in from some northern state, and had daily temperatures in the work area that commonly exceeded 120F (49C). We knew it was hot because the glass thermometers common back then popped after going over-range.

author: ayrex
author_rank: Contributor
timestamp: December 14, 2016, 11:47:43 pm
content: Quote from: CatalinaWOW on December 14, 2016, 10:50:18 pmDoes not all make sense. I'm sure these laws made sense when they were created. But some of them should be brought to the present time.In Europe we have the ATEX directive2014/34/EU.Not sure about the US but something is done as well (at least at companies; but I'm not very in these things for outside Europe).But these nozzles are real life savers! Not only for "special" people like the woman in the video. These electrostatic discharges while filling your tank is a real issue. Fortunately in most cases there is more lighting up a fire than an explosion.I guess there are many old laws or forgotten laws. And courts are taking them too serious if an lawyer pulls them out, arent they?Do you know why they don't modernize these laws or at least throw the useless ones in the dumpster?

author: CatalinaWOW
author_rank: Super Contributor
timestamp: December 15, 2016, 01:27:50 am
content: Quote from: ayrex on December 14, 2016, 11:47:43 pmLots of reasons they aren't modernized. The big one is inertia. Another is that few know why the laws were put in, and few understand whether they still apply. And at least in the liberal democracies, laws are passed by elected officials. They are motivated by what will get them re-elected. There is almost no big voting block demanding this type of reform.

author: Brumby
author_rank: Unknown
timestamp: December 15, 2016, 02:12:45 am
content: Quote from: CatalinaWOW on December 15, 2016, 01:27:50 amThis is very true - and not just in state and federal legislation ... but in business procedures as well.

author: Brumby
author_rank: Unknown
timestamp: December 15, 2016, 02:21:47 am
content: Quote from: ayrex on December 14, 2016, 11:47:43 pmThe reason why there is no major public outcry and demand that vapour recovery systems are fitted everywhere is because the number of events is so small when compared to the number of times people re-fuel their vehicles.Sure, there are consumer advocates that push these agendas, but the public is complacent, so no major motivation exists for those who have to foot the bill. Likewise, (as said above) the legislators are not driven to press the matter because votes aren't riding on it.

author: IanB
author_rank: Super Contributor
timestamp: December 15, 2016, 02:38:07 am
content: The primary reason for vapor recovery systems is not safety, it is for pollution control. The emission of VoC's from fuel pumps contributes to atmospheric pollution and smog. As such the number of events is not small, it is in the millions, every time anyone refuels their car.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: December 15, 2016, 02:56:15 am
content: True, but the number of places which have a persistent smog problem is relatively small. The LA basin is an obvious example, and is why vapor recovery is required in California. Denver is another. But many places have geography and weather patterns that let the problem be ignored.

author: StillTrying
author_rank: Super Contributor
timestamp: December 15, 2016, 03:32:29 am
content: "The gas pump nozzle sucks up the most gas vapor coming out of your tank while filling it up."What does it do with the vapour that's sucked out of your tank, and what does it do to the vapour when the gas station's tanks are refilled?

author: SeanB
author_rank: Super Contributor
timestamp: December 15, 2016, 04:03:42 am
content: Vapour goes into the fuel supply tanks to replace the fuel pumped out, and when the bowser refills the same again. Then in the refinery the vapour is simply either passed through to a condenser to get some volatiles back out, or more commonly sent through to the flare line to get burnt with the rest of the unused fugitive emissions in the refinery.

author: retrolefty
author_rank: Super Contributor
timestamp: December 15, 2016, 04:36:32 am
content: Quote from: StillTrying on December 15, 2016, 03:32:29 amStations here in California have on-site thermal-oxidizers to burn off the hydrocarbon vapors.

author: sainbablo
author_rank: Regular Contributor
timestamp: December 15, 2016, 02:28:29 pm
content: Quote from: IanB on December 10, 2016, 08:54:11 pmExcuse me but you mean the gas is already leaking ?

author: sainbablo
author_rank: Regular Contributor
timestamp: December 15, 2016, 02:42:14 pm
content: [quote author=CatalinaWOW link=topic=79621.msg1091577#msg1091577 date=148Lots of reasons they aren't modernized. The big one is inertia. Another is that few know why the laws were put in, and few understand whether they still apply. And at least in the liberal democracies, laws are passed by elected officials. They are motivated by what will get them re-elected. There is almost no big voting block demanding this type of reform.Sounds very familiar to me

author: sainbablo
author_rank: Regular Contributor
timestamp: December 15, 2016, 02:51:46 pm
content: Quote from: ayrex on December 14, 2016, 07:14:16 pmAny relationship with degree of moisture in surrounding air?

author: JanJansen
author_rank: Frequent Contributor
timestamp: December 15, 2016, 04:23:32 pm
content: If Lipo battery falls hard it might ignite if it breaks, it goes if some air is in it.Samsung phones explode with no reason, maybe they tried to fit to much mAh in a to small space ?If you drop it, it might not explode directly, slowly the crack getting worse until it catches air, and explode at some moment,always use something like bump free protection is the best.

author: ayrex
author_rank: Contributor
timestamp: December 15, 2016, 05:45:13 pm
content: Quote from: retrolefty on December 15, 2016, 04:36:32 amExactly. It has a name in german. "Gaspendelleitung". And if there's too much pressure in the main tank. It'll release it to the environment (with a safety valve, unidirectional).Quote from: JanJansen on December 15, 2016, 04:23:32 pmDepends on the case of the device and the construction (in mobile devices often "tea bag" cells. That happens because the cell seperator is damaged and there is an internal short in the battery. It'll become hot. --> exothermal chemical reaction (which produces oxygen, hydrogen and other) --> hotter --> battery will expand --> breaks at the determinded breaking point --> gas comes out, which is highly flameable --> if battery is hot enough --> it'll ignite it (if the battery can produces an explosive atmosphere if it's not outside).Here a video where the battery is at first not able to ignite the vapor coming out of it. and than: A spark or too hot surfacehttps://www.youtube.com/embed/AAZ62tUtc0wHere is a video where the battey won't become an ignition sourceI think Samsung did not try to fit too much capacity in their faulty batteries, they made a faulty safety circuit. It won't cut the current at too much battery drain or too high temperature. So the battery's seperator can be damaged by too high temperature.They should have used a proper safety circuit and maybe a bigger battery. But that costs cash and reduces the place for electronics.

author: JanJansen
author_rank: Frequent Contributor
timestamp: December 16, 2016, 02:54:25 pm
content: That guy with the knife is crazy.The axe man is more wise, he straps it to something heavy so it wont fly away.( He better buy Turnigys instead of Zippy )

author: sainbablo
author_rank: Regular Contributor
timestamp: December 16, 2016, 04:24:04 pm
content: I have an old model of Huawei. Ten minutes on viber made it really warm. took the battery out. It was warm.As mentioned, faulty batteries short circuiting sparking can explode at place of their choice causing damage by cascading progressionof the event ( cf Catalina). So then it is matter of luck ? Or environments ? Who gets what?Two explosion have been reported here but further details are scanty. There are lot of cheap batteries circulating from near and far east marketsBut then in final run, what is the significance level that is p= what?

author: CatalinaWOW
author_rank: Super Contributor
timestamp: December 16, 2016, 06:08:22 pm
content: Quote from: sainbablo on December 16, 2016, 04:24:04 pmNo one can tell you what the p is. It is extremely low, but is it 1E-6 or 1E-12? No one can say. Gas station fires are fairly common, but only a fraction lead to explosions, and many have no specific cause identified. See the following for example. It identifies ignition of flammable liquids as the source of fires in a variety of circumstances, but the source of ignition for the flammable liquids is not identified. The majority are the standard culprits, an open flame, cigarettes or other smoking materials, sparks from battery hookup or welding, spontaneous combustion in oily rags and the like, but there is no definitive characterization for every event.Fires at U.S. Service StationsMore information"Fires at U.S. Service Stations" report (PDF, 222 KB)Fact sheet"Fires at U.S. Service Stations" fact sheet (PDF, 34 KB)Related reportNFPA members2010 "Selected Published Incidents Involving Automobile Repair Shops" report (PDF, 57 KB)Contact usIf you have any questions, e-mail Nancy Schwartz or call +1 617 984-7450.Report: NFPA's "Fires at U.S. Service Stations"Author: Ben EvartsIssued: April 2011Incident types and trend data are reported for fires that occurred in or at service stations. Three different types of incidents, structure fires, vehicle fires, and outside and other fires are analyzed for cause, equipment involved, and other type of material first ignited, among other relevant factors specific to each incident type. Other information relevant to this occupancy, such as the hazards of static electricity is presented as well.Executive SummaryDuring the five-year period of 2004-2008, NFPA estimates that U.S. fire departments responded to an average of 5,020 in service or gas station properties per year. These fires caused an annual average of two civilian deaths, 48 civilian fire injuries, and $20 million in direct property damage. The majority of the fires in this category were vehicle fires. Reported fires in this occupancy group fell 46% from 7,860 in 1980 to 4,280 in 2008.According to the U.S. Census Bureau, there were 117,000 gasoline stations in the United States in 2007. Fires in these occupancies represent a variety of incidents, including structure fires, vehicle fires, outdoor fires and other fires. The majority of incidents are vehicle fires (61%), but the majority of the property damage (59%), results from structure fires. Outside trash or rubbish fires account for 12% of the fires reported to local fire departments at this type of property.Twelve percent of fires reported to local fire departments in these properties were structure fires. The most common items first ignited in structure fires at service stations were flammable and combustible liquids and gases, piping or filter (22% of structure fires), followed by rubbish, trash, or waste (18%) and electrical wire or cable insulation (13%).Most vehicle fires (82%) occurred in passenger vehicles, these fires accounted for nearly half of the total number of civilian injuries that occurred in service station fires of any kind (structure, vehicle, outside, other). The most common type of material first ignited in a vehicle fire was gasoline (28%).Outside and other fires accounted for 15% of incidents at service stations. Natural vegetation fires accounted for 42% of these incidents. The most common heat source for outside fires was smoking materials (21%).Twelve percent of fire incidents at service stations were outside trash or rubbish fires.Individuals interested in keeping service stations safe from fire should consult NFPA 30A – Code for Motor Fuel Dispensing Facilities and Repair Garages for information about fire prevention in these properties.1U.S. Census Bureau, Statistical Abstract of the United States: 2010, Table 740 “Economic Census Summary” (NAICS 2002 Basis): 2002 and 2007The report summarized above has the following paragraph on cell phones, which is somewhat self contradictory.Static electricity has been confirmed as a cause of refueling fires, but cellular phones have not.Three percent of vehicle fires at service stations between 2004 and 2008 were coded as having unclassified static discharge as the heat source (this coding excludes electrical arcs or sparks). According to a report by the Australian Transport Safety Bureau (ATSB), “between 1993 and 2004, there were 243 reports of fires breaking out at petrol stations due to mobile phones. However, according to Dr. Adam Burgess of the University of Kent, not one of these incidents occurred as a result of a sparking mobile phone. In fact, there is no evidence that any petrol station fire has been ignited from electrical equipment”. The Petroleum Equipment Institute echoes these findings via its “Stop Static.” campaign. According to its website “So far, we have been unable to document any incidents that were sparked by a cellular telephone, In fact, many researchers have tried to ignite fuel vapors with a cell phone and failed.”The statement above that not one occurred as a result of a sparking mobile phone is a case of making something true by wording it carefully. I would hope it means that all mobile phone users were interviewed, and the fire did not start at their phone. Assuming truthful reporting that would establish that sparksin the cell phonewere not the source of the ignition. I am also not surprised that people operating a cell phone in a test chamber filled with fuel vapors have not ignited them. If it is a rare occurrence you must run an absurdly large number of tests to randomly hit on the combination of things that must go wrong. Even if you focus on doing stupid things it may take hundreds of trials to get a failure. Think of the experiment of tossing a burning match into a bucket of gasoline. It usually doesn't cause ignition. But I doubt that many people would then say that doing it hundreds or thousands of times would be safe. I also don't see how you can eliminate the possibility that a Hertzian resonator could have been involved. Such a resonator is an unlikely but possible happening with a random bit of wire or an aluminized chips package.

author: sainbablo
author_rank: Regular Contributor
timestamp: December 18, 2016, 05:26:05 pm
content: Quote from: CatalinaWOW on December 16, 2016, 06:08:22 pmThanks for an exhaustive reply. Time to figure out if such information exists locally in all the domains of technology

author: ayrex
author_rank: Contributor
timestamp: December 19, 2016, 12:40:39 am
content: A colleague said once before "Explosion protection is sometimes done esoteric". He meant that they are overtraveling the goal by lightyears. And on the other side they neglect functional safety... in combination: FAILIn most cases you're beyond the upper explosion boundary (ignition results in a fire) and sometimes you don't even reach the lower explosion boundary.But I can tell you a common way I determine it when I have to assess it: Zone 2 = in case of a failure or within a extremly low period of time regularly with a maxium, summed up amount of 30 Minutes a year. Now it depends on how long we think there would be an atmosohere. 1 second maybe? --> 1800 times a year Or 1 minute? --> 30 times a year.And in that short amound of time there have to be an ignition source. So ther're two probablities which we must multiply.And you're right! Nobody can tell us the real probability. The data for statistics depend on various other factors. Like wind. Technical equipment. Temperature.I don't trust any statistic which isn't manipulated by myself

author: CatalinaWOW
author_rank: Super Contributor
timestamp: December 19, 2016, 01:23:14 am
content: I think it is impossible to get a meaningful quantitative answer for this problem. I believe I can set up a credible case in which an explosion or fire would occur. Credible in this case meaning no violations of physical law. But beyond agreeing that it is very unlikely for this case to happen (whatever that means to everyone involved), I doubt that further progress can be made.It comes back to my earlier question. Are the benefits so great as to be worth taking whatever the chance is? This answer is largely subjective and will vary from individual to individual.An analogous case comes from driving in my area. I am in a rural area and traffic is light. Typically less than a few dozen cars a day pass, but speeds are high 50-65 mph (80-105 kph). By observation, many of my neighbors have decided that the time saved by just driving out of their driveways without stopping and looking is well worth the small chance that someone is coming by. There have been no accidents in the time I lived here, so they will tell you they have experiential proof that their evaluation is correct. Others might disagree with that assessment, including me, as I have been involved in more than one very near miss.

author: Brumby
author_rank: Unknown
timestamp: December 19, 2016, 05:22:28 am
content: Quote from: CatalinaWOW on December 19, 2016, 01:23:14 amI believe it could be done, too. It would require a much more considered approach than the haphazard method used by the Mythbusters - but I believe it possible.Quote from: CatalinaWOW on December 19, 2016, 01:23:14 amI like that analogy - very much - but I will take it a bit further by changing just one word.... from "Typically less than a few dozen cars a day pass" to "Typically less than a few dozen cars a year pass". This puts the scale of the analogous risk into similar territory - but one day......