There may be no substance on earth as desired and sought after as gold. The soft yellow-red metal is relatively rare and has been used for currency and jewelry for millennia. Nearly everyone has or has had a gold item in their home at some point or another. But when they brought that gold into their life, did they also invite a fire risk in too?
Gold is not considered to be flammable, though it will melt. Gold is one of the least reactive substances known to man and it will not burn in air at any temperature.
That doesn’t mean that you can afford to ignore the effects of heat on gold entirely though, here’s what you need to know.
Your # 1 priority is keeping your family safe. As a firefighter, I recommend everyone has updated smoke detectors that don’t require battery changes, like these ones from Kidde, a fire extinguisher, like this one from Amerex, and a fire escape ladder if you have bedrooms above the first floor, I recommend this one from Hausse.
Also read: What Makes Something Flammable?
What Is Gold?
Gold has a chemical symbol of “Au” (that’s from the Latin word ‘aurum’ which means gold) and it’s a heavy metal.
It’s soft as metals go and it can easily be shaped into nearly any form, particularly as it is also ductile (a property that makes gold suitable for use in the electronics industry).
It is solid at room temperature and is found in nature in its elemental form (nuggets, veins, ores, alluvial deposits, etc. are all pure gold).
It is sometimes used in alloys with other metals to create slightly different properties.
It is also, rarely, found in compound form in some minerals.
Its most common usage is as a precious metal for coins and jewelry but it is also used in infrared shielding, gold leading, dentistry, electronics, and even in medicines.
There are about 200,000 tons of gold that have been mined and are in circulation in the world today.
The largest producer of gold is China.
Is Gold Flammable?
Gold is not in the remotest bit flammable.
To be flammable, a substance should be a liquid and ignite at temperatures of below 199.4 degrees Fahrenheit or 93 degrees Celsius.
At this temperature, gold is an unreactive solid.
Also read: Is Iron Flammable? Sometimes…
Why Is It Non-Flammable?
We won’t go too deep into chemistry here, but gold has an “inert” electron configuration which means that it finds it very difficult to react with any substances.
This means that while Gold Oxide might be theoretically possible, in reality, gold just won’t burn with oxygen, this is even true when you melt the gold down.
Will It Burn In A House Fire?
No, because gold isn’t very reactive, it won’t burn in a house fire. But it could melt, depending on the temperatures reached.
Also read: House Fire Temperature: How Hot Does It Get?
Does Anything React With Gold?
Gold is a very unreactive metal and that means it won’t dissolve in acid (well most acids, to be precise), it won’t burn in oxygen and even in the presence of highly reactive halogens (chlorine, bromine, etc.), it won’t react very well either.
However, that’s not to say it won’t react at all and gold does exist in compound form, and, perhaps, the most common is a compound with Tellurium, AuTe2, which is a mineral found in the Earth’s crust.
Will It Rust?
Rusting refers to the oxidation of iron in the air.
Over time, with a little water and some oxygen, iron reacts with oxygen to produce Iron Oxide which is the reddish-brown flakey material we call rust.
Gold doesn’t react with oxygen under extreme heat, so, perhaps unsurprisingly, it doesn’t react with oxygen at room temperature with water present, either.
So, gold will not rust.
Does It Turn Green With Age?
Anyone who has owned jewelry will know that it can turn green as it gets older, but doesn’t that contradict the idea that gold doesn’t react with the air around it?
While it is true that some gold jewelry will turn green over time, it’s not due to the gold reacting.
In fact, 24 Karat gold, which is pure gold, doesn’t turn green.
But as you add impurities, those impurities can react with the air and turn green or tarnish.
It’s most common in jewelry rated under 14 Karats of purity.
You can delay tarnishing the cheap metals blended with gold by cleaning the piece after wearing it and avoiding colognes, hairsprays, etc. coming into contact with it and also by avoiding foods with high levels of acidity.
Does Gold Hold Heat?
The surface of the gold is reflective and that means initially if heat is directed towards gold, it reflects it away (in fact, this is why gold is used to coat the visor for astronauts).
However, once it starts to warm gold is a conductor of heat and that means it will warm through fairly quickly.
However, once the heat source is removed, the gold will cool down rapidly as it will radiate the heat out.
What Happens To Gold If Heated?
You’re probably thinking that like all metals, this is obvious, when you heat gold it must get softer, right?
Well, in fact, a recent paper from the University of Toronto, showed this to be wrong.
When gold is heated it actually gets harder rather than softer!
This is due to the heating causing gold’s stable electrochemical outer layer to be pushed further from the nucleus of the gold atom, making it easier to bond with other gold atoms, apparently!
Does It Heat Up Fast?
Yes, gold has a very low specific heat capacity and that means it heats up very fast when compared to other metals.
Gold will gain heat at about 7 times the rate that aluminum does, which is why aluminum foil is a much better thing to wrap a turkey in before you pop it in the oven.
This is a good thing as if we had to wrap our food in gold foil, we’d probably starve due to the costs of the gold.
Does It Turn Black When Heated?
Pure gold doesn’t turn black when heated though impure gold may get some tarnish on the surface, in fact, if you heat pure gold – it becomes cleaner on the surface and thus brighter and shinier.
At What Temperature Does Gold Melt?
Gold melts at a temperature of 2000 degrees Fahrenheit (or 1064 degrees Centigrade), which means that if you have a house fire, it might meltdown, but it won’t catch fire and it won’t be lost.
How Much Gold Do You Lose When You Melt It Down?
You lose no gold when you melt it down as it won’t vaporize and it won’t react with other materials.
In fact, gold is only really lost during sawing, filing, etc. when it’s being shaped into something else (like jewelry), in these processes approx. 10% of the available material is lost.
If you ever visit a jeweler that claims around 50% of the gold is lost, you might want to go somewhere else, they’re ripping you off.
Does Melting Gold Purify It?
Yes. This is, in fact, the easiest way to purify gold and it was used to purify gold back in the Middle Ages when more complex processes were not available.
It’s worth noting that you shouldn’t try this at home, molten gold can set your house on fire and cause serious burns (as Game of Thrones fans know it can even kill you).
Can Gold Be Destroyed?
There is no way to destroy the molecular makeup of gold using anything that occurs naturally.
So, in principle, gold can’t be destroyed in any ordinary effort, however, it is possible that dumping it into the heart of the sun or using a fusion or fission reaction on gold, could break down the molecule.
How Toxic Is Gold?
Gold is not particularly toxic given its low levels of reactivity.
Also given the costs of gold most people will never have the opportunity to consume enough gold to be poisoned by it.
However, if you were to get enough gold into your bloodstream then it would give you heavy metal poisoning, eventually.
How Much Can A Person Consume?
Gold is non-reactive.
So, you can eat as much of it as you like, as long as it’s pure 24 Karat gold, it will just pass through your digestive system and out the other end.
This is why, occasionally, you will find food and drink products that contain gold.
Can It Kill You?
In theory, gold could kill you if you got enough of it in your blood but due to its low reactivity, this won’t happen in practice through any natural process.
So, the only way that gold could kill you in real life is if you somehow ended up being crushed by it or being dropped into molten gold, these things are also very unlikely to happen.