Daily MOS: The Unharnessed Chlorine Trifluoride

As a chemist, I’ve handled plenty of dangerous, hazardous, and toxic stuffs. Explosives, pesticides, biological specimens? Pass the hot sauce.

But there are some chemicals on this Earth that no amount of riches, sexual favors, or a promise of eternal world peace would convince me to work with. One in particular reacts to almost everything, burning viciously, and the way to fix it once you have an accident? The foremost experts on it recommend “a good pair of running shoes.”

Today in a Moment of Science… Chlorine Trifluoride.

Ever try to do a chemical warfare and succeed a little too hard? That’s basically what happened with chlorine trifluoride. Under the codename N-Stoff (substance N), it was researched at the Kaiser Wilhelm Institute because Germans in the 1930s were highly interested in self-lighting flame throwers for some crazy reason. They also thought perhaps this could be used for rocket fuel but 86’d that because they finally found something too risky for the Nazis.

It reacts with just fucking everything. Water? Uh-huh. Air that’s a smidge too humid? Totes. Humans? You’re a fleshy sack of water. Glass? Oh, it’ll burn right the fuck through glass. Titanium? Lol. Cement? Say buh-bye to your flooring. Pre-burnt material? It’ll resurrect ashes to burn them again. Diamonds? Not. Fucking. Forever.

It’ll even set fire to asbestos. A quick reminder, we blanketed the planet in a layer of fluffy carcinogenic fibers in large part because they were so darn good at resisting fire. Chlorine trifluoride is all “lol burn” to your stupid fucking cancer rock.

If you’re anything like me your question here is… what in the ass?

If you can shake the mental dust off your high school chemistry, you might remember oxidation reactions. A molecule loses electrons to an oxidizing agent, commonly oxygen. Oxidation reactions create your metal oxides (including rust). The breakdown of sugars in respiration is an oxidation reaction.

Point is, oxidation doesn’t look like one kind of thing. It’s one of the most simple and common mechanisms in chemistry.

But then you introduce a really strong oxidizer and shit is wild. And how does this happen? A few reasons, but not least of which is electronegativity, the property of attracting electrons. The second most electronegative element is oxygen, not surprising as our go-to oxidizer. But coming in first and third? Fluorine and chlorine. So a compound made by mashing the two of them together? It’s the Veruca Salt compound, it wants those electrons now and it’s not shy about getting them.

Furthermore, its reaction can have some particularly nasty byproducts. Hydrochloric acid is already a strong acid, but then we add hydrofluoric acid, which is neurotoxic. Unlike other acids that will “just” leave you with a chemical burn, hydrofluoric acid will fuck up your life after you’ve cleaned it up. In 1994, a lab technician in Australia spilled hydrofluoric acid on his lap, and immediately followed robust safety protocol. But HF starts working on damaging your nerves after it’s absorbed into your system, and can cause cardiac arrest. The technician died two weeks later.

How do you even handle something like this? Effing carefully. A fluorine-lined tank of steel, copper, or aluminum can contain it safely. However, if the fluorine coating is disrupted in any way? The ClF3 will start reacting violently with the metal container.

How have attempts to work with this safely gone so far?

Hooboy.

In the 1950s while it was being researched as rocket fuel, they loaded a literal ton of it into a steel container to ship. As a safety precaution, they chilled the container with dry ice. But it became brittle, cracked, and 2,000lbs of the stuff was spilled on the building floor. Witnesses reported that it burned through a foot of concrete and three feet of gravel beneath that. The chemical formed a gaseous combination of chlorine trifluoride, hydrogen fluoride, chlorine, and hydrogen chlorine, corroding everything it touched.

As much potential power as chlorine trifluoride has, without a safe way to handle it? It will likely remain shelved, a chemical curiosity that couldn’t be truly harnessed. It’s been relegated to extremely limited industrial uses, is no longer being researched as a rocket fuel, and I deeply hope Elon Musk never catches wind of its existence.

This has been your daily Moment of Science and a reminder to keep extra shoes in the lab.

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