What a government's legitimate purpose is, is beyond the scope of this discussion. Killing customers is bad for business, and people are more than capable of choosing their own pros and cons as to various gas cylinders. I'm more than content to leave them to it.
Others introduced governments: as UK and EN* gas safety regulatory bodies already exist, it seems reasonable to wonder how those bodies would respond to A4 canister/appliance problems as mentioned by G1gop up-thread, preferably before customers die. Whether governments accept that response into law is a different discussion, but the EU appear to have accepted the recent valved 206 rule (206GLS). (*EN417 is an EU standard (I can't find any sign of subsumption by ISO but it seems be accepted internationally, why bother diverging... I presume it will morph into an ISO standard eventually)) Perhaps future posts could be limited to how such existing safety bodies might respond?
Butane is stupidly inexpensive given the BTUs in the bottle: Around 10.6k (a 8oz can) per $0.75-1.25, white gas being around 114k per a little less than $9 locally, if I could actually buy a gallon can. That comes out close to equal give or take price fluctuation.
I've never had a problem with my cassette stoves and they seem to be fairly common in Asia. Soto makes dedicated camping stoves that (ST-310, Fusion) that take the notched canister (AFAIK they're called CB in Japan?) and Iwatani is huge in the cassette stove market. I can always find a cassette stove at the local Chinese and Korean supermarkets in California and the butane as mentioned is stupidly dirt cheap. I have to wonder if the real problem is more of improperly designed stoves that do not lock onto the canister than the canister itself. Australia for a brief period banned cassette stoves that didn't pass testing and I do see UL marking on my GasOne. The Iwatani is a Japanese domestic model which I trust to be safe give the Japanese regulatory environment. The canisters themselves have an UL marking and from my research on them, a company in the US tried to make some with the marking minus actual UL tests and they got into enough trouble that they went out of business after UL sued them for putting the mark on. The canisters were heavier built that they made a boneheaded move by putting the UL marking when they weren't listed. First off the nozzle isn't plastic: My Iwatani stove has a little magnetic element that secures the container when it is pushed up against the magnet and what looks like a thermostatic element hat pushes it back loose if it gets too warm (from oversized pots or such) and the GasOne I have has a lever type mechanism which pushes the canister forward. They both have a little "finger" element that prevents the canister from being improperly inserted, they align with the notch against the canister. Without it being aligned they simply will not let you insert the canister enough to push the nozzle to allow for gas flow. From what I can tell, Japan and Korea have some seriously stringent stove standards and the canisters are used domestically. To the point where contraptions like this exist to run several in parallel as a set: I recently got another adapter to my collection which mounts the canister vertically onto a tripod base. For a fairly "simplistic" locking mechanism of formed sheet metal that allows them to mount, it is plenty secure. I can pick the entire assembly up by the canister and it doesn't want to detach unless I make an active effort to unlock it as I mentioned in my post. Some of the other adapters I have which can be used vertically orientated (Kovea but especially the Campingmoon) are quite secure as well not to mention easier to mount (Push and twist + Straight on depressing it until it clicks on) and easier to mount without leaking gas like the threaded systems. There's no real reason to proclaim that the cylinder is bad given how many of them get used. They're more common than the threaded lindal connection (which in itself has some downsides given the roll formed steel thread wears on the softer brass thread of the stove). I don't hear about cassette stoves exploding into a ball of fire all across the US given how common they are.
Here are the alignment fingers/tabs on my Iwatani and GasOne cassette stoves. The GasOne type of mechanism (lever actuated) seems to be more common for cassette stoves. On the Iwatani the bottle needs to be pushed until it clicks against the collar and the collar then seats against the regulator and valve body. The GasOne is a little more clumsy in that the finger is spring loaded so the can has to be inserted with a little bit of maneuvering to make sure it slips into the notch. The thread where the bottle goes is because the GasOne will take a propane hose that goes into a 1lbs propane bottle (and as far as I can tell with an adapter it'll run off a 20lbs tank).
It's the GasOne type that I have seen catch fire a few times. They seem to be more common in the UK. The problem is they are often put in clumsily at an angle and that nicks/wears the small o ring that forms the seal. Then leak. Had one at the camp site this weekend leak. Didn't cause a fire but they dumped it.
Looking into the GasOne, I noticed that it has a chamfered surface for the nozzle to align in. I have to wonder what kind of square peg through circular hole type would stick the nozzle straight into the relatively recessed o-ring (It looks like the o-ring of a modern threaded backpacking stove, minus the threads) before forcing the bottle down using the lever. The mechanism of the Iwatani is much easier, the magnetic collar sucks up to the bottle before the collar and bottle stick right into the valve/regulator body. It is fairly foolproof since it won't really insert down unless both of them are aligned. Looking at the Campingmoon adapter I have, there is no exposed o-ring on the outer surface like the GasOne's fitting but rather the o-ring is where the nozzle would insert. I guess this would protect the o-ring from any misalignment of the metallic nozzle since it would be axially constrained by the narrower opening. I see a similar configuration in many of the twist on types. The Fire Maple base and adapter I have seems to use a similar small o-ring but it is placed more outward than the twist type adapters. It seems the o-ring is on a sprung assembly as well. The G-Works uses a flat piece of rubber which is unusual but it looks similar to the way that the propane type seals against.
The only place I can find those prices are small Asian markets, and the only reason I know about that source is through careful research here and others. That's 100x more than the average camper is doing. They're buying whatever's on the shelf at their local box store.
The little quart bottles of MSR Superfuel, Crown Camp Fuel at REI and such are between $8-13. At 0.25 of a gallon they represent 4x+ the price. Here is a list I put together out of personal curiosity since I wanted to figure out how much overpaying would occur for the quart cans. BTUs used per pound: Butane: 21,300 Propane: 21,600 White Gas / Gasoline: 19,000 Kerosene: 19,850 Methanol: 8,419 Ethanol: 11,570 Isopropyl: 12,960 Pound per gallon (gasoline/kerosene, alcohols for reference): Gasoline: 6.0lbs/gal (114,000 btus per gallon) Kerosene: 6.8lbs/gal (135,000 btus per gallon) Methanol: 6.6lbs/gal (55,565 btus per gallon) Ethanol: 6.6lbs/gal (76,362 btus per gallon) Isopropyl: 6.54lbs/gal (84,758 btus per gallon) If we're normalizing against btu/$: Long butane canister 14,133 - $0.75 cassette canister of butane (4 pack from the Asian Supermarkets) 8,480 - $1.25 cassette canister of butane 5,325 - $2 cassette canister of butane (Online shipped for 12 or 24 cans as of 8/31 Amazon/eBay, also close to REI Kovea can) 3,533 - $3.00 cassette canister of butane (Walmart) Camping isobutane 1,033 - $5 canister of 4oz/110g isobutane/propane mix 1,721 - $6 canister of 8oz/220g isobutane/propane mix 2,066 - $10 canister of 16oz/450g isobutane/propane mix Propane 1lbs 5,837 - $3.70 1lb propane canister 6,171 - $3.5 1lbs propane canister when bought as 4 pack Propane bulk 21,600 - $15 (Approximate) Propane Exchange for 15lbs 24,000 - $18 (high pice) propane fill for 20lbs White Gas 12,808 - $8.90 Gallon of Generic Camp Fuel/White Gas 8,769 - $13 Gallon of Coleman Fuel 5,277 - $5.40 32oz/quart of Coleman "Premium Blend" Fuel (Amazon price as of 8/31) 3,562 - $8 Quart of Generic Camp Fuel/White Gas 2,192 - $13 Quart of MSR Superfuel Kerosene 15,000 - $9.00 Gallon of Generic Canned Kerosene 11,250 - $12.00 Gallon of Klean Heat/More refined Kerosene 19,285 - $35 Five Gallon Can Kerosene (bulk pricing) Automotive Gasoline (toxic/nasty) 45,600 - $2.5/gal pump gasoline 28,500 - $4.0/gal ("California prices") pump gasoline Pump Kerosene and Diesel 45,000 - $3.0/gal Kerosene price based on NY State data as of 8/31 (No pumps in my part of CA) 42,769 - $3.25/gal Diesel price based on CA average from AAA as of 8/31 Charcoal Lighter Fluid (Napatha/Kerosene/??? mix mystery) 13,804 - $4.60 64oz Low Odor/Odorless Charcoal Lighter Fluid (Napatha approx 127,000btus per gallon assumption) Alcohols 4,394 - $15 Gallon of Denatured Alcohol as 50/50 methanol-ethanol (Californians and several other states are screwed over unless you can buy "alcohol camp fuel" where it is in stock) 2,386 - $8.0 Quart Denatured Alcohol Mostly Ethanol 4,120 - $4 Quart Denatured Alcohol assuming 50/50 3,260 - $1.6 12oz (0.094gal) HEET bottle (100% methanol) 2,825 - $120 4x Gallon of 99% Isopropyl shipped (8/31 prices) 9,888 - $1.5 70% isopropyl 32oz (Assuming that 70% can burn well enough in a stove or is dried for "no real cost", didn't subtract boiling water losses, just used 0.70 multiplier) 7,712 - $2.5 91% isopropyl 32oz (Non pandemic prices and availability, as well necessary stove modifications) For reference, gas company prices assuming 30 cents a therm (100,000 btu) means natgas is a monsterous 333,333 btus per dollar (minus connection charges/etc) assuming a line is connected to the home. Surprisingly the $0.75 a pop can of butane is stupidly competitive price wise for the convenience of usage. Pump gasoline is cheap but nasty stuff. Pump kerosene where available is as good as gasoline in price. Buying white gas or kerosene in non gallon things always sucks. If 0.05 liters of white gas is consumed per day as a budget that represents 75(+0.7) days worth of cooking from a gallon can, or an approximate 1,500 btu a day budget (assuming some lost in priming process). Realistically 75 days is overkill for the average camper or backpacker so the quart will likely be the impulse buy for a solo camper or backpacker. Isobutane numbers I have found seem to be around 15-20+ grams per day (500-1000 btu/day budget) per person which are where the 5-10 days for a 110g can numbers are from. Using the "worst case" scenarios for a week's worth of consumption then the minimum purchase price is $8 for quart of white gas and $5 for a 4oz/100-110g canister respectively. Adding a dollar to jump to a 8oz/220g canister isn't bad at all. Of course, buying even the most expensive long butane canister comes out ahead of that if the stove can run on it at $3 a can given they're half the price of the 8oz isobutane canister. So for the average Joe no matter what it costs a little under $10 for a week. Using white gas would leave around another week and a few days to spare from a quart can. Buying the isobutane canister costs a little less if an 8oz one is used and 4 bottles of butane is stupid dirt cheap if stoves could run on them straight up. If the average Joe didn't care about weight, buying a propane canister would be the technical cheapest big box store option if they needed the convenience and btus. Of course using a backpacking stove means an adapter and possibly stabilizers. For the stove enthusiast the super cheap cans of butane are as good as a gallon of kerosene or white gas in regards to the range of btus per dollar. I find cooking for a group of 3 I can get a bottle to last around 2 days-ish for full "home cooking" so there's absolutely no guilt in using an adapter and being able to run any stove I want. Alcohol in the table too for anyone that did conversions of existing liquid fuel stoves. If you can get your stove running on cheap isopropyl it is great stuff for the cost. Low guilt to run given the cost is a little better than a 1lb can of propane. It is safer than white gas, minus any of the shutdown vapors of white gas and kerosene.
Thanks, thats a bit reassuring about the cylinders (and interesting that dedicated hiking stoves do exist,and lots of other interesting stuff): I am still a bit puzzled about why the A4-canister-designer(s) (who I wonder ?)designed in the (metal) nozzle: surely a canister without it is simpler and just as cheap?
I looked into it and it seems that Iwatani made the first notable cassette stove in 1969 and it was called a "cassette-feu." That format of portable stove seemed to have become popularized and other similar cassette stoves were released afterwards. That seemed to establish the JIS S S2147 standard, which defines the cassette stove that takes the notched collar canisters. Around 1991, the JIS S S2148 standard came into existence. In 1998 the standard was revised to make it so there's only one specific "shape" of canister due to a quake in 1995 that required standardization of the canister. These canisters are referred to as "CB" canisters in Japan. Japanese canisters are from a quick glance, made in Japan and Korea so they must have a domestic operation going on. Perhaps this is where the "inertia" of the metallic valve stem is from. How accurate the one size part is I am not sure as I have seen "short" and "long" versions of the collar type canister as pictured in the photo of the triple adapter I uploaded earlier. Perhaps that short canister is from another standard or it is the obsolete type. A similarly shaped canister (8oz/220g approx, long and tall) minus the notched collar is available in various formats, from unthreaded to threaded and with and without the nozzle. While looking into it, I found the collarless, threaded type of canister seems to be more common in Europe. Briefly researching I found that GoSystem among other companies seems to sell one of those types without the notched collar and with a threaded valve. The European reference to the cassette stove type canister with the notch is referred to as "bayonet" cartridges and even sell propane mixed ones which resembles some of the Soto "CB OD" (OD = Outdoors?) type which has propane mixed into it like the common backpacking canister. Photos attached of the collarless version of the GoSystem type along with a Soto (propane mix?) with the same "threaded" configuration: While looking at a picture of the GoSystem canister (curiously: listed as EN417 even with the collar and nozzle - I assume EN417 is actually pressurized canisters and not the valve), I found that there is something called a "MSF-1 CRV" standard or feature which is indicated by the blue ring around the top seam.. It is apparently the equivalent of a rupture disk to prevent overpressure from blowing up the canister. I've attached an image showing what it is and I'm surprised at what the blue ring around the seal is now. I looked at my own collection and found what looks to be an alternative system. One of them is instead marked "TSR." I've attached photos of the mentioned as well: As a guess I assume these are things that industry itself has adopted to try to imitate the safety mechanism of the overpressure valve found on propane canisters. Having spoken to a friend in the Netherlands, it seems he can buy Sievert style canisters (long slender canisters with a thread, no protruding valve. From what I can tell they may be more slender or I am looking at the 300g+ ones) for less than he can buy propane for. It seems that the same format of long screw on cartridge is also available in Sweden and other countries where I rarely see them in the US: There are some high propane content or pure propane canisters similar to the Sievert ones, they typically have a rounded top or ridged and are screw on. They seem to be related to the refrigeration industry as well. The ones I can find in the US are sold as "green gas" (airsoft gun propellant) and are filled with propane and silicon oil: This is a little off post but further research of cassette stoves seems like some companies sell different degrees of safety systems to them in regards to the valve and regulator. Perhaps this is where the reputation of cassette stoves going up in fireballs is from (or the lack of a safety feature in some cases?). I did read in the manual of my cassette stoves that they incorporate a gas cutoff and definitely will eject the cartridge if the assembly gets hot. I assume stoves released in different countries with different regulatory standards will influence what system is shipped.
Before I forget: I did find an image of the smaller "CB"/"A4" cartridge but I can't edit it into the above post due to the 10 minute limit. Ah, I forgot to say this in the post previous now that I think about it: I suspect it is just the inertia of the supply chains and how common those cassette stoves are to the point that it makes more sense to sell them with the notched collar and with the external valve stem versus otherwise. They're already widely consumed in larger numbers and the economy of scale must be what makes them less expensive than the insane prices that are associated with camping style isobutane canisters. Then again, taking a look at Japanese prices they seem to be a less than us but I can only assume that is a function of shipping distance or having domestic canners of gas. 300-something yen for 4oz/110g meaning $2.83 as of 9/1/20, or around close to half the price and 700-something yen for 16oz/450g... Makes sense then.
A 'Lightweight Mini Cassette 'Pocket' Camping Gas Stove' (375g): Lightweight Portable Folding Camping Gas Stoves No big names seen to have followed suit although Go outdoors still seem to sell a tripod converter for cantop stoves.
