This Gas Burns through Stainless Steel

What Caused This?

Fluorine gas is very, very dangerous. Here's a sampling of the chemical dangers cited on the database:
"CHEMICAL DANGERS: The substance is a strong oxidant and reacts violently with combustible and reducing materials. Reacts violently with water producing toxic and corrosive vapours: ozone (see ICSC0068) and hydrogen fluoride (see ICSC0283). Reacts violently with ammonia, metals, oxidants, and many other materials, causing fire and explosion hazard."

I used to run a fluorination facility, and am well familiar with just how deadly fluorine gas can be. The valve in the picture above was part of a small system to transfer a few cylinders of fluorine. Everything was going fine until right up to the end, when something caused an ignition. the valve and all piping had been meticulously degreased prior to the operation. All piping, valves, cylinders, etc, were gradually exposed to increased level of fluorine mixtures to insure that nothing was left to react.

But with fluorine gas, there is always something left to react.

Years ago, a fluorine expert advised me that even the flow rate of fluorine gas through a high quality stainless steel system was enough to generate an exothermic reaction that would vaporize the metal. I never believed him.
But I've seen it happen.

Move the flow rate up too quickly in a fluorine system at your own peril.
But there is a fluorine gas compound that's an even more vigorous oxidizer: chlorine trifluoried.
Read what Derek Lowe has to say about it on his blog:
"In a comment to my post on putting out fires last week, one commenter mentioned the utility of the good old sand bucket, and wondered if there was anything that would go on to set the sand on fire. Thanks to a note from reader Robert L., I can report that there is indeed such a reagent: chlorine trifluoride.
"I (Derek Lowe) have not encountered this fine substance myself, but reading up on its properties immediately gives it a spot on my “no way, no how” list. Let's put it this way: during World War II, the Germans were very interested in using it in self-igniting flamethrowers, but found it too nasty to work with. It is apparently about the most vigorous fluorinating agent known, and is much more difficult to handle than fluorine gas. That’s one of those statements you don’t get to hear very often, and it should be enough to make any sensible chemist turn around smartly and head down the hall in the other direction.
"The compound is also a stronger oxidizing agent than oxygen itself, which also puts it into rare territory. That means that it can potentially go on to “burn” things that you would normally consider already burnt to hell and gone, and a practical consequence of that is that it’ll start roaring reactions with things like bricks and asbestos tile."

I've had the pleasure of working with chlorine trifluoride myself. A co-worker and myself were looking at using it in ppm range as a replacement for ethylene oxide in medical sterilizer applications. Talk about stress.

But here's my point in bringing this topic up: most university research labs and industrial research labs can use small amounts of these materials for their research projects and either aren't required due to the quantities or just plain don't report them to the HAZMAT teams responsible for the area region that they're operating in. It's a serious, serious problem. Some of these small amounts- such as lecture bottle quantities- can cause very big problems.