Paraffin Wax Autoignition 

I've got a Ph.D. in chemistry, taught college for 35 years, had never seen such a thing, and think this is a delightful video! Wish I'd had it while I was still teaching. Good job!

We did this in high school in 2003 by accident. My teacher asked to see it again, then told us to never do it again. We didn’t understand what had happened, but we were simply igniting it without the ice. The fireball was impressive. Left a black ring on the ceiling. We all still have and still had our eyebrows…

my parents used to seal preserved fruit with wax and i remember them warning me about wax vapors. mom melted the wax bars in a double boiler to keep the temperature at or below boiling water temp, and took it off the stove immediately upon melting to seal the jars of preserve. fascinating to see what they were worried about.

Very impressive demo. For a fun and safer demo, light an ordinary paraffin wax candle. Once it has burned for a bit, snuff it out. Wait a few seconds until a nice stream of "smoke" (actually vaporized and condensing wax) forms, rising upward. Light the top of the stream with a lighted match. The stream will ignite, and the fire will run down the stream and re-ignite the candle.

Immersive waxing of bike chains (at ~ 200ºF/92ºC) is becoming more popular, because it is better than mineral oil, but some holdouts are citing paraffin's supposedly super-flammable properties to argue against. it. I'm glad that this video exists, so that I can point to it to prove that you have to boil it & then super-cool it to make it auto-ignite, and that doing so in a slow cooker or double-boiler is nigh-on impossible. Thankyou Phil.

This is an excellent video to show why paraffin oil shouldn't be used as a heating media in a oil bath while setting up a high temperature reaction !

At almost 45 years of age, I might have to take a chemistry course, thanks to your short videos.

That slow-mo close-up was excellent! Quite a video! 😎✌️

That's a good visual representation of stoichometry in action. Ignition occurs first at the point where the air/fuel mixture is optimum

This explains the accidents that occur or have occurred in candle factories or accidents at home making decorative candles, which have resulted in children with third degree burns. Thanks for most.

I used to make candles. Thank you for showing just how dangerous paraffin can be.

I have heard of people using paraffin to heat homes, to cook and even power a refrigerator (typically you see them most often in 3rd world countries). I have also seen that the paraffin can cause fires and severe burns to people. This illustrated why it happens. Thank you!

I remember my chemistry teacher in high school loved showing this off. Always been a favourite of mine.

Dude has a pretty sweet fume hood. I’m jealous, the one I had wasn’t this cool

I've never seen such before. And yes, it raised my awareness of what NOT to mess around doing....

Excellent demonstration, never herd this trick till now 👍

Beautiful, I mean the explanation as well as the process itself.

This is the most incredible video I've seen in a while. My eyes went wide as saucers seeing the short, and I had to look up an explanation which led me directly to your main video haha!

I use paraffin wax at work. Thankfully, we’re not getting it more than about 100 degrees Celsius, usually no more than 85-90. Past 100, you start to smell it. I guess the boiling water mixing with it at that point starts to do weird things with it. Makes sense now.

tried that several times years ago with a metal can. heated it to boiling, poured in a small amount of water (using a spoon tied to the end of a stick), and watched it go FOOM.

As kids in 1962 we used paraffin to wax our surfboards. We learned it lasted longer if we would melt it in an old tin can then brush it on our boards. Our parents told us to be careful not to get it near water while we were doing this but never told us why. Now much later, I finally know! (We never got it hot enough to boil - just enough to stay melted while we applied it to our boards). In high school chemistry we learned about state change and a drop in temperature as paraffin is heated to melting but nothing about autoignition - probably a good thing at that age LOL!

I remember covering a paper in wax and rolling it and setting it to fire. It sort of exploded and wax spread around it. I never understood how that happened but after seeing your video i think it was the same phenomenon. Thanks 🙏👍

Very good explanation, I used to always be confused by this!

This was soooo imteresting thanks for showimg and explaining in such good way! As soon as you showednthe slow motion i started to figure out whay it is igniting but it is always best to have someone who knows toexplain the extra bit:) Thank you. Subscribing for sure!

I love these *to the point* videos, I wish YT was more like this ❤❤❤

The arson investigation over my gramma's house burning down around her concluded that she did this while making candles in jars to cool them faster and caught the drapes over the sink, then flames went behind the cabinets catching the foam insulation.

Guy sets up a fairly dangerous seeming demonstration for us featuring fire and reactions and thanks US! Bravo Mr. Scientist, I know paraffin is a monster to tidy up so: Thank You 🙏🏻!

Thanks for this video. Many years ago I burned wrist badly by accidentally doing this. I had no idea why it happened until now.

Ah you've finally explained it! So many people were speculating so many wild different things in the original video. Most of them made little sense to me. I don't remember exactly how I arrived at the right answer. I think I saw another video of someone explaining that the glass cracks and rushes in. It's also possible that one of the many explanations from people mentioned it.

Thanks! Knowledge saves lives!

Wax has a very high specific heat capacity of about 2.5 J/gK -- not quite the value of water which is extremally high at nearly twice that of wax but way higher than steel or copper or aluminum. So, when the wax was heated to boiling the heat contained in the wax was enough to instantly vaporize enough water to cause the wax to jet upwards and increase the surface area exposed to oxygen. The energy content of wax is also quite high -- about the same as many fuels we use.

I love the “let me show you what I mean” and then just an incendiary goes off

Great safety video to demonstrate a form of a BLEVE (boiling liquid expansion vapor explosion). In reality these catastrophic events happen when a superheated tank ruptures. Here the sudden formation of a heterogeneous azeotrope causes a quick vapor expansion.

I did this on small scale when i was 13, i was very cool, and it never left my mind

Want to hear a Potassium joke? K!

Wow! That was awesome! Culver is a nice school. Love going out on lake.

This my favorite thing to do back in the day.. we’d get a whole little metal bucket of wax in a campfire melted to the point it was “on fire” where the surface looked like it was burning.. then we had a bucket of water taped to a rake we would dump onto it and get a fireball 10’ high! We called them “wax bombs”.. really takes me back.

more of this long-form content please!

You remind me of my own highschool chemistry teacher, Mr. Topping. He would do really cool demonstrations for the class.

Youve been most helpful. 😊

Holy crap that's awesome!! A two sided fume hood!

Funnily enough I have done this, My dad worked in wax for a big oil company so there was always blocks of wax about at home.

Very nice!

Good info. Thanks.

I'm going to try this!

Great video. Here's an idea for a future video: explain why gunpowder needs a little sulfur to work.

Just tested this. Awesome.

This might be a good place to tell my little story. It was a cold winter, and the central heating was broken and could not be fixed for a few days. I was feeling cold as hell, and needed to get the room temp up, so I placed seven tea-lights on a small porcelain plate and lit them. It did work fine, giving some very welcome warmth. I had of course ensured that nothing flammable was nearby or above. After some time, all the wax had melted, which isn't unusual with tea lights, however the heat was enough to make the wax boil, and of course the gas ignited immediately with a giant flame, and now the tea lights were continuing to burn as one huge surface of fire, like a pan on a stove with burning oil. I quickly found a metal lid or pot or whatever and placed it over the plate with the tea lights, which killed the fire, but when I removed the lid, it would immediately reignite, until I left it to cool down. No harm done. But it sure was a learning experience. Even tiny tea lights can pose a serious danger! Don't place multiple tea lights close to each other. (I can't recommend repeating this experiment, but if you ignire my advice, at least do it in a safe location, keep the tea candles in a pan for which you have a tight fitting metal lid. The lid will get very hot, so use good insulating oven gloves.)

Subbed because you’re awesome

I've worked in oil and gas industry. Raw parrifin is clear black. Really flammble.

I’m more impressed by that fancy yard stick with the claw on the end affixed with painters tape!😂😂😂 Ahhhh… science!🧪

And this is why spilling water into a overheated casserole of melted paraffin wax causes a fireball?

Fantastic

Oh man. I have to try that!!!

Very good

Going to school in the 60s and 70s as much as I loved science having a learning disability I always sucked at understanding it. Watching videos on the subject I always wish we had the technology back then we have nowadays.

This is very familiar to people who home-can foods. A layer of wax on top of a jar of homemade jam or relish will keep air from touching the food. But melting and pouring all that wax can sometimes lead to ignition of the wax vapors. Instead of wax, the patented canning jars keep food fresh without the risk of fire. Since I used to make homemade treats and give them as CHristmas gifts, I was much happier using the commercial canning products, so my wrapped gifts didn't leak.

Very interesting.

I used to take scrap wax and fill a coffee can. The coffee can would sit in the middle of a bonfire. Eventually the vapor would ignite above the fire itself. If you were to spit in it, it would eject a ginormous column of Fire!

I instantly wanted to try this at home

always did wonder about rags soaked in linseed oil needing to be discarded in a self sealing container.

We did a similar trick, but dropped hot wax drip-wise into a pan of cold water. It didn't always flare up, but when it did it was dramatic!

Awsome thank you

I came to watch this because I still have a package of paraffin wax. Forget the water, let's go out where no one is around and use something more explosive....lol

One of the experiments I like to show too. There is another experiment where you can show that heating paraffin-oil at boiling point for some time generates gaseous and liquid cracking products (alkens). So I guess this and the intermediate formation of radicals might play a role in this self inflammation(?)

I feel bad for the first guy to figure this out

finally, a use for that old bag of Ikea tea lights !

Basically the frozen thanksgiving turkey in hot oil thing

When we were kids we would melt the wax (not boil) and throw into a tub of cold water. It made cool sculptures.

So cool❤❤❤

Very unintuitive behaviour, but the video is straight to the point and explains it well!

The heavy thick oil type compounds seem to have a lower auto ignition temperature, wax is probably close to diesel, gasoline has a higher auto ignition temp, and methane is probably even higher.

1:24 "It cracks". Watching the initial video made me think of the MythBusters episode where they dropped a frozen turkey in hot oil. Hilarity Ensued when the ice melted and then pushed up the oil, overflowing the pot and igniting it.

Never thought that overheated molten paraffin can be so dangerous.

I will try this at home.

So cool

Same occurs with sugar dust in refineries

My grandma used paraffin wax when plucking poultry to remove the fine hairs on the skin. Melted over the bird, cooled, then peeled. I remember those packaging boxes too. If I had known this back then, I think I might have advised against using it, lol.

This used to be "a game" back in my day, we called them "dragoncitos" (little dragons), we made them because they gave out candles, like the ones on a birthday cake, it was fun, but looking back, probably we are lucky no one got a major burn outside of a missing eyebrow perhaps. I'm not going into detail of how we made it, but most of the stuff we found in the trash or laying on the street.

gonna mess with the people at the skate park when i ask to borrow their wax next time hehe

You should definitely invite the Slow Mo Guys to your lab, I'm sure you can make awesome videos together!

Nice.

Thats cool, but the sound it makes up close at the very end just sounds so funny to me

The reaction is impressive and scary at the same time ! Also, I was wondering, why are there what seems to be two gaseous phases (a more cloudy one on the upper part of the tube and a coloress one between the cloudy one and the melting paraffin) at 1:04? Are they the different substances from the paraffin with a different melting point and density ?

I had a candle explode in a cabin a few years back. I thought the tin can i was using as a candle holder somehow turned into a spring via some kind of bi-metal reaction but now i wonder if the wax wasnt slowly boiling away until it got some cold snow through the window. I was sleeping and only saw the immediate aftermath but it was clear that wax had sprayed.

As someone famous once said, "Fascinating." 😉

Gotta try that when the Chem teacher's back is turned.

I did not know that, but now I do! cool

The reason why i heat wax for my bike chain in a water bath.

Reminds me of my ex's cooking! Not kidding the smoke detector was the dinner bell. Funny story, set my shirt on fire like that. My son said "daddy do it again! I wasn't ready with the camera!" He had a RU-vid channel at the time too.

“But the glass will crack!” “Yes, that makes it all happen!”

Paraffin is used in home canning jam/jelly which I now realize is very dangerous. I once created a fireball by just tossing the molten wax into a sink in the chem lab. Saves some steps

mr white thats really wild

We have a day known as Mid-Autumn festival back in Hong Kong, people would sometimes light many candles in a mooncake case, our parent always warn us not to do that, this is the reason why.

If be interested in a video on the chemistry behind self ignition of oily or solvent soaked rags when piled up

Let grade school boys watch this, and in 10 years we will have the best chemists in the world.😊

RIP to the guy cleaning the paraffin from the fume hood!

The paraffin doesn't vaporize upon hitting the ice water. It is the the water that enters the tube and is heated by the paraffin to steam. The steam projectiles the paraffin into fine droplets, which ignite due to a large contact area with oxygen. Futher, the micron sized droplets have a lower energy for ignition, a similar phenomenon happens in dust explosions. This means that the collision energy of tiny droplets releases enough energy to ignite with oxygen the paraffin.

I'm gonna do this

Interesting, as a kid I used to play around with tea lights and burn gummy bears and chips etc in them. Suddenly there was a ~2m jet flame that was even really loud. Now I know what must have happened. Has really sprayed the flame at that time.