(www.goodmorningamerica.com)
Turns out people leave perishable and fermenting foods in the thermos, and after a while when opened, the pressure lifts the lid of the thermos at quasi-unimaginable speeds, striking the curiously unsuspecting humans straight in the face, with some instances causing permanent damage to vision.
Coffee is hot, but a pressure release system is cool too..
> Incidents/Injuries: Thermos has received 27 reports of consumers who were struck by a stopper that forcefully ejected from these containers upon opening, including complaints of impact and laceration injuries requiring medical attention. Three consumers suffered permanent vision loss after being struck in the eye.
That's an awefully large amount of reports about this. I wonder what about the design makes it a rocket compared to what I would assume is a pretty standard design?
> The Stainless King™ 470ml Vacuum Insulated Food Jar is the ultimate day to day companion to keep your food at optimal temperatures. Keep fruit fresh and vegetables cool for up to 14 hours while you take on the day. For your favourite soups, pastas or stir fry, they’ll stay warm for up to 9 hours – ideal for taking last nights left overs. You can be sure that your food will be perfect for consumption at lunchtime after you pack it in the morning. The wide mouth makes it easy to fill and clean, and comes crowned with a stainless steel lid that doubles as a serving bowl. Plus, it comes with a handy stainless steel spoon that fits neatly into the lid compartment.
It's meant for storing food, for anyone who is confused why someone would be.
(to be fair, I don't think an externally threaded cap will solve this problem. If the thread held to a higher pressure, then the core part of the plug will eventually blow out even more energetically. An overpressure vent port is still necessary)
Injuries nonwithstanding, the quality of the seal means it was an exceptionally well designed item for the purpose of storing 99% water.
side note: there's a reason you get a visit from the FBI if you buy ten pressure cookers (e.g. if you find a great Black Friday deal and have a large family and plan Christmas gifts...)
If you were purposely fermenting something, you could build enough pressure to pop the bottle.
If the difference is, say, a full 360° turn, pressure will get relieved before the lid can come off.
See also https://news.ycombinator.com/item?id=48006887. Apparently, many bottles have discontinuities in the threading to allow for that.
Scroll down in that article to the section with photographs of "recalled" and "not recalled" lids side by side.
I was initially surprised too, because I mostly know Thermos from their coffee/water/etc bottles, but apparently they're also selling these with the intention of storing perishable goods, and in that case a pressure relief system of some kind is a necessity.
Often bottles have special threads with holes in them to let out the pressure when you twist them open, but it appears they didn't do that here.
"Is this user error?"
No. If we're recalling a product for a safety issue, it is not user error. There is an engineering error, or a design error, or a manufacturing error. Whatever the product is doing it should not be doing.
What point are you trying to make here ?!?!
Given that it should be there, it is quite clearly a product feature on Thermos jars.
So, of many examples that cross my mind.... let's say you were a long-term user of Thermos products. There's your "expectation".
I assume it probably features in the product literature that comes in the box too.
I've never seen a thermos-style container with a pressure relief in my life. However, I'm European, it appears that in the US (a country where you have to write disclaimers on microwaves that you shouldn't dry hamsters in them) common sense has been going down the toilet.
Frankly, I'm all for a bit of darwinism here. It's bewildering that there are people who think it's a good idea to open a thermos that has been fermenting for days if not weeks without a lot of caution!
Seems to be like they sold a bottle designed for a pressure relief cap with the wrong model cap, turning food storage containers into launchers.
I said "given it should be there" because Thermos have just issued a recall notice where they openly admit liability and they openly state it should be there (see side by side photos in the recall).
I was never seeking to pass judgement on the factual element of whether "it should be there" in the pure definition of the term.
I was just saying "it should be there on THAT product because Thermos says so".
That by far is not enough to forcefully yeet out the cap, probably not even if you take it to an Antarctic research base in -40 °C outdoor weather.
People forgetting about content that ferments however? Kaboom.
Happy now?
It can be seals that buckle before the lid. It can be a tiny hole with a soft rubber stopper. It can be one of many things that cost a couple of cents extra and a bit more engineering and testing effort.
The cheapest disposable coffee cups I've used have a tiny hole for the express purpose of not pressurizing and spilling hot liquid everywhere.
There's a lot of conversation in the comments about "was there was an expectation that the pressure release valve would be there" There absolutely is a safety expectation that a sealed container of hot food is designed with a pressure release system.
BTW the fermented food thing is a misdirection. The pressure release system should have released pressure way before it even reached ballistic territory.
That's not very empathic of fellow people who might just have mistakenly forgotten food in the container.
It's not like they were intentionally using this for brewing some illegal substance or misusing it in a way specifically forbidden in the manual or obviously unsafe (e.g. removing a magnetron and all of its protections from a microwave to make pretty wood carvings).
Can you also guarantee with absolute certainty that you'll never forget them anywhere another person who's unaware of the contents or the danger could find them?
The malfunction is due to multiple models of containers missing a pressure relief function in the center of the stopper.
I didn't consider it a defect, though. I can hardly imagine cheap products adopting this solution.
I can totally see how that would fly straight up at your face.
But then I read the words "The malfunction is due to multiple models of containers missing a pressure relief function in the center of the stopper."
How non-existent does your quality assurance have to be in order to miss such a critical, obvious and easy to identify flaw ?
Looking at the published photographs, you don't even need training to identify that manufacturing defect. A five year old could spot the difference between "lid has a hole" and "lid does not have a hole".
Not all safety features have to be obvious/obtrusive.
Me standing there, kombucha and peach slices pulverized against the cap, kombucha leaving a large mark on the ceiling it all happened so fast, glad I was wearing my glasses.
No injuries except my pride, but it did take some hours to clean up.
I wouldn't do it in a thermos, but I guess those are mostly accidents?
Tasted okay though.
My mate brewed his bramble beer by putting his brambles through a juicer and only adding the juice and pulp, because he's cleverer than me and has a certain amount of foresight.
Looking at the version that's not recalled, I would guess it costs more to make.
My partner has one of these so just checked it. It does have the pressure relief feature, but it turns out it's also missing all the seals anyway so never would have been a problem!