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"What Happens To Chlorine Gas Canisters With Time?" Topic

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18 Mar 2018 3:42 p.m. PST
by Editor in Chief Bill

  • Changed title from "What Happens To Chlonine Gas Canisters With Time?" to "What Happens To Chlorine Gas Canisters With Time?"

745 hits since 17 Mar 2018
©1994-2018 Bill Armintrout
Comments or corrections?

Personal logo Cacique Caribe Supporting Member of TMP17 Mar 2018 11:03 p.m. PST

How corrosive is chlorine to the canisters?

Under the best of conditions, how long can Norinco Cl2 canisters remain buried before they start leaking?


Of course, the weapons manufacturer says that the canisters have many potential industrial uses:


But if they are buried in desert sand, and their location is somehow forgotten, how long before they begin to leak?

PS. The Syrians and the Free Syria Forces are apparently both using Norinco chemical products now. Sometimes directly from Norinco, and sometimes via intermediaries like North Korean ships. The Iranians are experts at handling Norinco chemical canisters too.

Personal logo DuckanCover Supporting Member of TMP18 Mar 2018 2:45 a.m. PST


I have to preface this reply by saying that I've never dealt with high pressure gas cylinders intended for the transport and/or storage of chlorine gas.

Short reply: Potentially, could be a decade or more before an actual pressure drop might show on a gauge.

Long Reply: I was, for many years, responsible for the periodic hydro-static testing of both aluminum and steel alloy cylinders designed for breathing air (as might be used by a fire department, for instance). Part of that testing, understandably, was visual inspection of both interior and exterior surfaces of each cylinder, prior to more rigorous testing.

When the stored air in the cylinders, at pressures of between 200 and 310 bar, was clean and dry those cylinders could definitely maintain the desired pressure for years beyond their mandated inspection interval. Indeed, cylinders may even exceed their specified service life (in the case of some fiberglass reinforced types) and still maintain their integrity.

I've personally owned several small cylinders which I deliberately maintained as an informational exercise, where both testing intervals and service lives were exceeded, in a couple of cases, by as much as fifteen years. When checked for content pressure, all were as full as I originally filled them. However, because of the time involved, the air contained therein would have been statutorily deemed "unfit" for breathing (did smell odd, I can tell you).

The biggest enemies of pressure vessels are mechanical damage and moisture levels for which the cylinder was not designed. Moisture and any gas, even inside a cylinder designed for that particular (dry) gas, can create an unpredictable chemical environment inside even the sturdiest cylinder.

Presumably, of themselves, cylinders for chlorine gas would be sound for years or even decades, as long as their environment was appropriate. In isolated desert areas, such cylinders could develop leaks which could remain undetected until checked, and then found partially or completely empty. Unless leaking was still taking place, if the cylinders were buried in the open, presumably the gas would have long dissipated.

I guess from a speculative point of view, if simply hidden/buried and forgotten/abandoned, for an extended length of time, there would be a high likelihood of leaking/partly empty/empty cylinders.

Affixing explosives to a pressure cylinder and causing those explosives to detonate when the cylinder was dropped from an aircraft would bring about predictable results (as per claims regarding "informal" use), no matter what the cylinder contained.


Personal logo Cacique Caribe Supporting Member of TMP18 Mar 2018 2:50 a.m. PST


Excellent information!

What prompted you to keep those air cylinders for that long? Personal curiosity?

Also, if the pressure showed no change, what do you think made them smell foul? Do you think that moisture in the air inside was reacting with the interior of the cylinder itself?

And were these cylinders stored in a stable, low moisture environment, or were there wide temperature and humidity fluctuations?

Thanks so much.


Personal logo DuckanCover Supporting Member of TMP18 Mar 2018 3:15 a.m. PST


Thanks, happy to help.

In answer to your first question: The cylinders concerned had all been discarded/abandoned by the original owners. One had a capacity of only a liter. Most were odd sizes that had fallen out of regular use. I became curious after having so many encounters with cylinders overdue for testing, that seemed to be holding their contents so well.

And to your second question: At my place of employment, we filled cylinders on site with medical grade air when we did refills, but not every user capable of refilling or having cylinders refilled was so careful. When I tested my cylinders, they got medical air. As per your speculation I too can only assume that some more esoteric chemistry was involved at the high pressures and over the time I chose. I have inspected breathing air cylinders which were originally connected to breathing sets (kept in lockers for immediate emergency use) that had as much as half a cup of water in them. That air smelled BAD. What would have befallen the BA set and the user, if they needed the set, was anyone's guess.

I could understand how the cylinders got in that condition, but could not understand how the owners of the equipment could permit the neglect to occur.

Oh and, as a postscript: In most countries the filling of any pressure vessel which is overdue for testing is an offense under law. I'm covering myself here by saying that, when I originally filled the cylinders for my long term test, they were all legal to fill. grin As years wore on, and their testing intervals passed… that would have been another matter. All would be retested before filling or destroyed now, as would be required by law. thumbs up


ROUWetPatchBehindTheSofa18 Mar 2018 7:25 a.m. PST

Could be along while, they dug some old gas cylinders out while re-engineering a landraise where I work, which must have been there at least one decade and as much as 2 or 3. It wasn't possible to tell if they were still pressurised, but they weren't in such poor condition that they obviously weren't. Oh, and the landraise is next to the coast, so plenty of salt and moisture…

bsrlee18 Mar 2018 10:02 a.m. PST

Chlorine + Water = Hydrochloric Acid. Would likely void the Manufacturer's warranty ;-) So if one cylinder leaked and there was any soil moisture you would get a lot of corrosion to all the surrounding canisters, pretty quick.

Personal logo StoneMtnMinis Supporting Member of TMP18 Mar 2018 10:58 a.m. PST


I have never found the storage of chlorine gas to be a big prob.…cough……cough…..cough..……gasp……………aarrrggggg……………………………………

Dave (recently deceased)

Personal logo Cacique Caribe Supporting Member of TMP18 Mar 2018 11:58 a.m. PST


Lol. You are one crazy man.


mollinary19 Mar 2018 3:44 p.m. PST

And this has to do with Miniatures how? Or is someone testing to see how quickly the intelligence services of various powers start knocking on people's doors?

Lion in the Stars19 Mar 2018 6:20 p.m. PST

Well, it's more a question of how long the threat of some jihadi digging up those cylinders will last.

The big thing about chlorine is that it's one of the few chemical weapons that isn't regulated by treaty: it's far too critical in industrial uses. Say, making water safe to drink.

Personal logo Cacique Caribe Supporting Member of TMP19 Mar 2018 8:07 p.m. PST

Mollinari: "And this has to do with Miniatures how?"

I think you are confusing this with something from the Ultramodern Gaming Board:
"For discussion of wargaming set within the past 10 years, including ongoing operations."

The Ultramodern Warfare Board is about recent developments and near future projections that may or may not get gamed:
"For discussion of military events within the past 10 years, including ongoing operations."


goragrad19 Mar 2018 9:19 p.m. PST

As to application to gaming, improvised chemical weapons could be a part of a scenario.

Personal logo Cacique Caribe Supporting Member of TMP20 Mar 2018 9:32 a.m. PST


Agreed! It looks like these days around the world anyone who is evil and determined enough can make chemical agents. Or simply buy them. Sadly that seems to be today's horrific reality.

So I think it's only natural that our figures and rules should include the possibility such scenarios.


Supercilius Maximus Supporting Member of TMP22 Mar 2018 3:31 a.m. PST

We have currently realised just such a possibility right here in the UK……

Personal logo Cacique Caribe Supporting Member of TMP22 Mar 2018 6:09 a.m. PST

Seriously? What happened?


Aristonicus01 Apr 2018 11:01 p.m. PST

I believe that S. Maximus refers to the claimed 'Novichok' attack on the Skripals in Salisbury.

Regarding chlorine however:

Chlorine gas is hardly ever deadly. It is 2.5 times heavier than air with a distinct yellow-green color and a strong bleach odor. Chlorine gas will only kill those submerged in a high concentration cloud. If one sees or smells it one simply walks away from the cloud and thereby stays safe. Chlorine was used as the first chemical weapon in World War I because it would creep downwards into deep enemy ditches. Even then it was soon found to be ineffective as a weapon and replaced with other chemicals.
That a few rockets with a few pounds of chlorine would have no 'lethal' effect is also obvious from official reports during the U.S. occupation of Iraq:

The first documented chlorine attack was Oct. 21, 2006, in Ramadi, a Multinational Force Iraq spokeswoman said. In that attack, terrorists drove a car bomb with 12 120 mm mortar shells and two 100-pound chlorine tanks. The attack wounded three Iraqi policemen and a civilian.
The first attack that received media attention was at Taji, where terrorists remotely detonated a 5-ton truck packed with 100 pounds of high explosives and two 1-ton chlorine tanks. The attack killed one civilian and wounded 114 others.

The most recent attack was June 3 against Forward Operating Base Warhorse, in Diyala province. Again, a suicide car bomber launched the attack, and officials estimate it included two tanks of chlorine and 1,000 pounds of explosive. The cloud from the attack blew over Warhorse and sickened 65 servicemembers, Multinational Force Iraq officials said. All were examined and returned to duty.

A Multinational Force Iraq spokesman said there are anecdotal reports that while the blasts from the attacks have killed, few have died solely from the gas. "We hear that an old man and some babies may have been killed, but we can't pin that down," the spokesman said.


Personal logo Cacique Caribe Supporting Member of TMP03 May 2018 5:19 a.m. PST

What does THIS look like to you guys?




BenFromBrooklyn03 May 2018 8:44 a.m. PST

This is not necessarily gas. Could be an improvised incendiary device.
Either way too inaccurate to be of value against military targets, and very illegal to launch at civilians.

Personal logo Cacique Caribe Supporting Member of TMP03 May 2018 2:20 p.m. PST

Some people claim that they are just "barrel bombs" or large homemade mortars:


A different article said it was gas.

And media keeps re-releasing those old images over and over, to make it appear as though whatever is currently happening over there now is somehow the result of the exact same type ordnance.

I don't know what they are, so I really don't know who the hell to believe anymore.


Lion in the Stars03 May 2018 5:32 p.m. PST

Looks like a propane tank with some bits welded on.

contents could be just about anything.

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