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[Laurent]

Contrary to what we’ve all assumed (including me)…..studies show it is not easy to the point of being unlikely (not impossible) for a cigarette to ignite gasoline. In fact outdoors it’s nearly impossible. It’s a combination of the narrow flammable range, an ignition temp around 500 f, and how quickly the temperature of that glowing end of the cigarette drops below the ignition temp of gasoline if the cigarette is not being inhaled or drawn in. Notice how when someone pulls on the cigarette the tip brightens and how quickly it darkens. Gasoline is much more dangerous as an accelerant than as the primary ignition source.


This is contrary to everything we’ve “learned” and assumed over the years including my industry. I guarantee you 9 out of 10 firefighters will tell you a cigarette is likely to ignite gasoline.

Who knew?

I was told that when a car is catching fire, it is much more dangerous with an empty gasoline tank, than a full tank. The car with the full tank will burn. The car with the empty tank will go:
KA-BOOOM !!!

Is that true?

 

[Poodle56]

KA-BOOM!!!

Happy Humpday Hobot!
Happy Humpday Punters!

 

[shaggy]

Half of California Silicon Valley has bought up the area since covid. Property values and access to cheap housing has gone sideways. Tragic City has no housing. Glen Arbor is a zoo in the summer. Other than that, yeah, anywhere around the pinky finger of MI is great.

I noticed that and wanted to get in on it if the Co market still keeps going nutz.. Saw an article where the state is going more blue as it seems to be a decent landing place for those fleeing the deep south and they also have $$. One stupid winter will send some back, but unfortunately the housing prices will stay high...

 

[veni vidi vici]

I apologize for the brief hijack- what's happening with a lit cigarette not igniting gasoline (petrol) is not the lack of vapor or lack of temperature, it's the lack of a stochiometric condition.

Gasoline ("petrol" to speakers of english) is producing ignitable vapors at any temperature above about -40F. IIRC the ignition point is around 350F, but gasoline vapor does not like to mix with air (which why engines need carburetors or injectors with fancy nozzle tips).
Go ahead
Yes you can stub out a cigarette in a cup of gasoline. Liquid gasoline does not burn (nor does any fuel, UNTIL it is mixed with oxygen).
until it vaporizes

However you're betting that the conditions over the cup cannot support combustion, which is easily possible under common conditions (because gasoline has a fairly narrow stochiometric window), but still a dangerous bet.

Go ahead and try it out for us

 

[veni vidi vici]

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Simpler times

 

[Grrr...]

I was told that when a car is catching fire, it is much more dangerous with an empty gasoline tank, than a full tank. The car with the full tank will burn. The car with the empty tank will go:
KA-BOOOM !!!

Is that true?

Not really. The tank is virtually air-proof and doesn't allow the air fuel mixture you need for an explosion. That's why so few explode. Most often the tank heats up, begins venting vapor, and the vapor lights and simply burns.

Boats explode with gas in the bilge because there is a height above the gasoline where the mixture is just right. And that explodes.

It's not much different than wood / flour dust explosions. You need the right density of dust in the air.

 

[Point Break]

I was told that when a car is catching fire, it is much more dangerous with an empty gasoline tank, than a full tank. The car with the full tank will burn. The car with the empty tank will go:
KA-BOOOM !!!

Is that true?

Well in theory yes. Remember it’s the vapors in the right mixture that “explode” so lower levels of gas have a greater chance of getting the right fuel/air mixture. It’s not a frequent occurrence. Vehicles with fuller tanks have the risk of tank or piping failure and then you have a rapidly growing fuel fed fire. Neither is wonderful 🤣.

 

[veni vidi vici]

Well in theory yes. Remember it’s the vapors in the right mixture that “explode” so lower levels of gas have a greater chance of getting the right fuel/air mixture. Vehicles with fuller tanks have the risk of tank or piping failure and then you have a rapidly growing fuel fed fire. Neither is wonderful 🤣.

What is the latest firefighting technique for lithium ion automotive batteries?
Nasty fires in multiple ways

 

[veni vidi vici]

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[Point Break]

What is the latest firefighting technique for lithium ion automotive batteries?
Nasty fires in multiple ways

Well…..I’ve been retired for 10+ years now so I’m probably out of touch with “cutting edge” tactics but it’s probably safe to say it’s evolving. Lots of water and patience was the current thought when I left. That is problematic because you need a good water supply and you’ll need to control/isolate runoff……..lots of it. I’ve never had one as they were not that common when I worked but after looking into it my thought was if it was safe……let it burn.

 

[veni vidi vici]

Well…..I’ve been retired for 10+ years now so I’m probably out of touch with “cutting edge” tactics but it’s probably safe to say it’s evolving. Lots of water and patience was the current thought when I left. That is problematic because you need a good water supply and you’ll need to control/isolate runoff……..lots of it. I’ve never had one as they were not that common when I worked but after looking into it my thought was if it was safe……let it burn.

Let it burn… other than the toxic smoke
Also water is also a contributing factor to the chemical ignition, there were multiple auto ignition fires around hurricane Ian and flooded areas. Several fires thought to be extinguished reignited afterwards.
Our condo has first floor parking and there have been discussions what to do going forward with unit owners wanting charging stations for their EV’s, scares the crap out of me with the thought of potential damage to other vehicles and utilities that service the building, along with structural damage to the concrete. We are not close to a decision but I am adamant about outside common access credit card charging stations for each building.

 

[Point Break]

Let it burn… other than the toxic smoke

That is a factor in the “if it’s safe” decision.

By the way….all smoke is toxic.

 

[veni vidi vici]

That is a factor in the “if it’s safe” decision.

By the way….all smoke is toxic.

Of course it is and some more than others

 

[hobot]

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[chinabald]

Great news.

Can I also smoke while pouring acetone, lacquer thinner, alcohol and MEK?

Let us know how it goes

 

[Latadjust]

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The face that says "...we are not amused..."

 

[warbird]

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James Garner's race team...

 

[warbird]

That is a factor in the “if it’s safe” decision.

By the way….all smoke is toxic.

I worked with wire and cable FRs for 6 years. The antimony based FRs are pretty toxic. The burning FR takes a lot of energy out of the flame front but releases toxins. Magnesiumhydroxide is an interesting FR, burning, it releases H2O which sucks energy as the H20 is converted to steam. Magnesiumhydroxide is more expensive so except for aircraft and a few other application, we don't see it in the US much.

 

[veni vidi vici]

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[MisterMoon]

I worked with wire and cable FRs for 6 years. The antimony based FRs are pretty toxic. The burning FR takes a lot of energy out of the flame front but releases toxins. Magnesiumhydroxide is an interesting FR, burning, it releases H2O which sucks energy as the H20 is converted to steam. Magnesiumhydroxide is more expensive so except for aircraft and a few other application, we don't see it in the US much.

I'm peripherally in the FR biz. There are all kinds of FRs with varying degrees of toxicity. One of our big businesses is self extinguishing hydraulic fluids for power generation and avaition. These are all phosphate esters and pretty safe, safer than having a fire in a coal fired or nuclear powerplant or on an airliner.