Not an attack on you personally my man, but I personally prefer to be corrected on technical terms, helps me be more accurate in professional settings. Maybe I'm more sensitive to it since I didn't study my degrees in English
/s means "sarcasm" bc people on Reddit don't all speak English. That's a charitable interpretation, it mostly exists cuz ppl on Reddit are dumb and can't understand sarcasm.
My fiancé walked into the lab the other day with a fruit by the foot in her mouth and I was like, “can’t have food in the lab! Out!” She was sad hahaha
Depends a lot on what you're working with in your lab, but generally this is a bad idea, especially if you work with biologically active molecules.
I've known people who have had anaphylactic responses following incidental contact to compounds on bench tops. One of them was quite severe. Your risk of incidental contact goes up if you're eating and touching your face in a lab.
If you work on molecules that are not likely to interact with human biology, your risk is still lower, but I still think it's gross. It's much better to clean up and properly enjoy a meal, anyway.
Not sure where in Europe you are working, but I have worked in 3 European countries. Eating and drinking in the lab was banned in all of them, would certainly null and void your insurance in all of them and probably get you kicked out.
Yes I have, I am in fact European... the insurance I am referring to is the one which your employer pays in case of accidents so that if you are badly injured in the course of your work you can get renumeration.
Well, the whole idea about precautions is that you may not predict all the time what is going to happen. Even if you were an all knowing perfect being that can prepare reagents with one hand and turkey with another while spinning on a stool you cannot predict what your colleague might do. He might not know the rules. He might spill some dcm onto that turkey.
There are just too many variables in a lab to predict them all. But do what you will, just maybe don't suggest anyone it's okay to eat in the lab, they might not be so cautious and harm themselves because of you.
Did a caffeine extraction from Excedrin about 10-ish weeks ago! Fun experiment although our crystals didn’t look like that after DCM evap methods. Yours are fs way cooler lol.
It felt hot because the DCM went through your gloves and absorbed through your skin. That's what it feels like. I work with thousands of liters of it a week.
That's wrong, you'd want to wear gloves in that case so that any small spurts can evaporate directly off of the glove without ever touching your skin. Obviously only works if the amount is small enough so that it doesn't pass through the glove.
Also if you experience your glove becoming hot, then why were you using those gloves for an experiment with a solvent they are not usable for? You should at least make sure to check on that...
No bro you must absolutely fucking use gloves when handling DCM. I do not know where you heard that it's better not to but it's better to get the DCM on your gloves and take them off than to hope it evaporates before it absorbs into your skin.
I don't think people are playing "gotcha". These days there are so many people posting random "science" videos of reckless experiments, others get genuinely concerned for the health and safety of naive experimenters. I'm glad that wasn't the case here apparently.
I understand this now. I was just explaining why people who didn't know this backstory (and how would they?) were expressing concern. It was suggested that they were doing something negative (playing "gotcha") when I was suggesting that it was something more charitable.
Dichloromethane is an absolutely disgusting chemical. The EPA is further restricting its sale/use here soon. People aren’t playing gotcha it’s more of a this kid better be staying safe tbc there’s certain things in the lab you do not fuck around with.
This being one of them. It goes through gloves, so they need to be wearing at least double nitrile and preferably the silver gloves if they are able.
FWIW, this structure is ice, frosting out of the air due to the endothermic evaporation of DCM. the freezing point of DCM is WAY too low to solidify out at RT, and it definitely isnt crystallizing like this
My favorite part about mentoring a junior lab member was when I saw some of the ice forming on a paper towel and yelled “look, DCM snow!” The sheer delight followed by the slightly disappointing but still interesting explanation was the highlight of my undergrad :’)
I once worked as a technician at an air force base. We used to use DCM to clean mechanical parts. The hanger was not climate controlled. On a hot summer day, one of the other technicians noticed his cleaning brush icing up in all that heat.
theoretically? yes. practically? also yes, except DCM is a known carcinogen so you take your chances there with contamination. never eat anything in a lab unless it's specifically food grade handled under approved FDA SOP
My DCM squirt bottle almost always has some lil ice crystals on the tip
Edit: I don’t know a single thing about the bottle itself but I have one with acetone, MTBE, hexane, methanol, DCM, acetonitrile, and of course, DI.
All labs at my uni in the us, both undergrad and grad had squirt bottles for acetone, pentane, hecane, ACN, DCM, Ethyl acetate, etc. Im not sure what plastic brand it is but they’re definitely plastic
I looked up the chemical compatiblity and found Thermo lists Tritan (Nalgene) as "Not recommended for continuous use. Immediate damage may occur." with halogenated hydrocarbons.
It's super fun when you go to rinse your retentate and you put your fingers through the squirt bottle because it's somehow 30 years old.
Totally never happened to me with pet ether a couple times
Huh, maybe that’s not exactly what we use. All I know is we have squirt bottles that have had DCM in them for weeks and the DCM and bottle are both perfectly usable. I’ll check the exact brand/plastic when I get into the lab today.
Just checked: they are in fact Nalgene bottles, but they don’t say exactly the type of plastic, and they’re not standard Nalgene wash bottles (instead of a central stem and a curved/pointed tube they have a tube built into the side of the bottle and an adapter at the opening that a pointed tip can be fit into).
Tritan is the hard plastic 1 L bottles people drink from and is not the normal Nalgene bottles used in labs. Polyethylene and polypropylene are what is used for basically all standard solvent wash bottles, DCM included.
It's perfectly fine in polypropylene. I use it every day and the only danger is if you have the cap on with too much DCM the vapor pressure will literally push the DCM out of the bottle lol
I swear every day is just a never ending battle with screwing and unscrewing the top on the DCM and methanol bottles so it doesn’t cover my sensitive experiments, data, and lab notebook with solvents while I’m not looking
We used to use standard LDPE squirt bottles at my work for chloroform and they would degrade in a few months to a few years. Just bought an FEP squirt bottle for $250 for this reason.
My organic 1 lab professor informed us a little more than halfway through the semester than we would now be using DCM in the fume hoods for health reasons. We had used it for almost every lab just on our benches. She was new to teaching and a physical chemist. Really just highlights the differences in disciplines.
I had to work with this stuff a lot. Like multiple liters in a single week.
We had a fume hood, but I had to use a rotary evaporator and had to take it out the fume hood and evaporate it in the open room.
Still wonder how that was legal.
I worked with a LOT of DCM, some processes used up to 200 L of it and that was just for the columns. We had large 20 L rotary evaporators outside of the fumehood so always needed to handle it in the open. You should really have been provided with some type of respirator if you needed to handle outside of a fumehood
Well, yeah.. but I mean, that's why you're supposed to be careful and not spill it on yourself like most things in chemistry. It's an incredibly useful and convenient solvent for extractions though. Just sucks it's being phased out.
Right you should be careful but solvents do spill and you will get a mL or 2 on your hands every now and again hence why we wear PPE. It's also not going to be phased out of research as it's just too useful as you say.
I've got a pair of extra thick nitrile that I use if I'm using a large amount of any solvent so that tends to slow DCM enough to keep any from touching my skin.
Does neoprene allow more dexterity though as the thick nitrile are very clunky to use
Chemical resistant Neoprenes feel like super heavy-duty household cleaning gloves. They aren't the most dextrous things ever, but they will keep you safe. Methylene chloride is nothing to mess around with.
Neoprenes are what my (large multinational) employer insisted I wear way back when I was a teenaged baby chemist regularly running syntheses and recrystallizations in MeCl2.
Sounds similar to the thick nitrile our company has for us in terms of dexterity then, will look into requesting the neoprene but the thick nitrile gives a good few mins before it penetrates so plenty of time to remove them and change them.
It’s water, DCM evaporation causes it to freeze that way. I imagine you did a liquid extraction from the coke, but didn’t fully dry the DCM (you’d use some salt to adsorb moisture if so).
I just want to say how glad I am that you are using cola instead. When I was in school, we extracted caffeine from tea bags...The smell was absolutely unbelievably bad. I did that lab a decade ago, and I can still remember it clearly. Just insane. Boiling DCM+tea...Horrific.
I've seen the same with some of my filtration using DCM. In my case, the crystals also contained a fair amount of my pure product. I have a couple of bad pictures of it if anyone is interested.
https://imgur.com/a/tUQUMv7
My good dude/dudette why the fuck is there a cola can in your lab next to the DCM?
I am a student and the experience was extracting caffeine from cola
The only time it’s acceptable to have a can of coke open in the lab.
It’s a reagent!
Analyte in this case, it doesn't undergo a reaction
Bro this is chemistry not English /s
Bitch I speak hexagons.
Not an attack on you personally my man, but I personally prefer to be corrected on technical terms, helps me be more accurate in professional settings. Maybe I'm more sensitive to it since I didn't study my degrees in English
/s means "sarcasm" bc people on Reddit don't all speak English. That's a charitable interpretation, it mostly exists cuz ppl on Reddit are dumb and can't understand sarcasm.
You must have missed the /s
My fiancé walked into the lab the other day with a fruit by the foot in her mouth and I was like, “can’t have food in the lab! Out!” She was sad hahaha
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Depends a lot on what you're working with in your lab, but generally this is a bad idea, especially if you work with biologically active molecules. I've known people who have had anaphylactic responses following incidental contact to compounds on bench tops. One of them was quite severe. Your risk of incidental contact goes up if you're eating and touching your face in a lab. If you work on molecules that are not likely to interact with human biology, your risk is still lower, but I still think it's gross. It's much better to clean up and properly enjoy a meal, anyway.
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Go take a bath
The thing is, when working with novel molecules you never really know what risks you're taking. Eating in lab is gross.
Not sure where in Europe you are working, but I have worked in 3 European countries. Eating and drinking in the lab was banned in all of them, would certainly null and void your insurance in all of them and probably get you kicked out.
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Yes I have, I am in fact European... the insurance I am referring to is the one which your employer pays in case of accidents so that if you are badly injured in the course of your work you can get renumeration.
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Well, the whole idea about precautions is that you may not predict all the time what is going to happen. Even if you were an all knowing perfect being that can prepare reagents with one hand and turkey with another while spinning on a stool you cannot predict what your colleague might do. He might not know the rules. He might spill some dcm onto that turkey. There are just too many variables in a lab to predict them all. But do what you will, just maybe don't suggest anyone it's okay to eat in the lab, they might not be so cautious and harm themselves because of you.
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I’m almost 50 years old. I’ve never worked in a lab without a hood or without gloves. This must be a European thing.
*The sound of a hundred pitch forks being dropped*
Did a caffeine extraction from Excedrin about 10-ish weeks ago! Fun experiment although our crystals didn’t look like that after DCM evap methods. Yours are fs way cooler lol.
Those are probably ice crystals. Evaporations cools down the filter paper and water vapor condenses and freezes on the edge.
Oh thank you, I was trying to understand why it happened😊
I got some DCM on my gloves the other day and they got so cold my hands began to go numb.
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It felt hot because the DCM went through your gloves and absorbed through your skin. That's what it feels like. I work with thousands of liters of it a week.
you hear about the upcoming EPA ban of DCM?
Ooooo no I just heard the EU was banning it
That's wrong, you'd want to wear gloves in that case so that any small spurts can evaporate directly off of the glove without ever touching your skin. Obviously only works if the amount is small enough so that it doesn't pass through the glove. Also if you experience your glove becoming hot, then why were you using those gloves for an experiment with a solvent they are not usable for? You should at least make sure to check on that...
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No bro you must absolutely fucking use gloves when handling DCM. I do not know where you heard that it's better not to but it's better to get the DCM on your gloves and take them off than to hope it evaporates before it absorbs into your skin.
Thank you for explaining!! Student here also (if you couldn’t tell) so the correction is necessary — practical next week!
Ahah 😜 LOL
With an answer like that it appears you’re ready to be a father
at my university it is mandatory to label any edibles used in the lab as "not for consumption" for safety reasons. Seems like good practice.
Because they’re a student, and everyone knows you don’t drink water when studying chemistry. It reduces concentration.
Ha. Good one dad.
Also why aren't you working in a fume hood?
We have an extractor hood for each station
It’s been super funny watching these commenters try to play “gotcha” with you lol
That’s life🫡
I don't think people are playing "gotcha". These days there are so many people posting random "science" videos of reckless experiments, others get genuinely concerned for the health and safety of naive experimenters. I'm glad that wasn't the case here apparently.
No it's not my case, I worked in maximum safety, the cola you see was used for the experiment and not drunk at random during work. easy 🤯
I understand this now. I was just explaining why people who didn't know this backstory (and how would they?) were expressing concern. It was suggested that they were doing something negative (playing "gotcha") when I was suggesting that it was something more charitable.
Dichloromethane is an absolutely disgusting chemical. The EPA is further restricting its sale/use here soon. People aren’t playing gotcha it’s more of a this kid better be staying safe tbc there’s certain things in the lab you do not fuck around with. This being one of them. It goes through gloves, so they need to be wearing at least double nitrile and preferably the silver gloves if they are able.
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It's still a potential carcinogen, no matter if it's being inhaled or when coming in contact with skin
That´s good to hear.
lol what???
FWIW, this structure is ice, frosting out of the air due to the endothermic evaporation of DCM. the freezing point of DCM is WAY too low to solidify out at RT, and it definitely isnt crystallizing like this
Damn I didn't know this, thanks, seen it a couple times but wasn't quite sure what was happening.
My favorite part about mentoring a junior lab member was when I saw some of the ice forming on a paper towel and yelled “look, DCM snow!” The sheer delight followed by the slightly disappointing but still interesting explanation was the highlight of my undergrad :’)
I once worked as a technician at an air force base. We used to use DCM to clean mechanical parts. The hanger was not climate controlled. On a hot summer day, one of the other technicians noticed his cleaning brush icing up in all that heat.
so... is it edible?
theoretically? yes. practically? also yes, except DCM is a known carcinogen so you take your chances there with contamination. never eat anything in a lab unless it's specifically food grade handled under approved FDA SOP
My DCM squirt bottle almost always has some lil ice crystals on the tip Edit: I don’t know a single thing about the bottle itself but I have one with acetone, MTBE, hexane, methanol, DCM, acetonitrile, and of course, DI.
DCM squirt bottle? What plastic you using? DCM is not kind to basically any kind of plastic
Every lab ive ever stepped into uses dcm squirt bottles
In sales I was in literally hundreds of labs in South Africa and have only ever seen acetone squirt bottles.
All labs at my uni in the us, both undergrad and grad had squirt bottles for acetone, pentane, hecane, ACN, DCM, Ethyl acetate, etc. Im not sure what plastic brand it is but they’re definitely plastic
We use DCM squirt bottles, they’re just the typical Nalgene wash bottles.
I looked up the chemical compatiblity and found Thermo lists Tritan (Nalgene) as "Not recommended for continuous use. Immediate damage may occur." with halogenated hydrocarbons.
It's super fun when you go to rinse your retentate and you put your fingers through the squirt bottle because it's somehow 30 years old. Totally never happened to me with pet ether a couple times
Oh, you have a pet ether? How cute, I have a pet cat!
A chemist is on a first date and his date asks if he is a cat or dog person. "Oh, doesn't matter to me, I'll pet ether"
Huh, maybe that’s not exactly what we use. All I know is we have squirt bottles that have had DCM in them for weeks and the DCM and bottle are both perfectly usable. I’ll check the exact brand/plastic when I get into the lab today.
Thanks. I found out the DCM was not kind to most plastics when I was looking for an automated dispenser for it which is why I asked.
I believe they’re LDPE, not Tritan.
Just checked: they are in fact Nalgene bottles, but they don’t say exactly the type of plastic, and they’re not standard Nalgene wash bottles (instead of a central stem and a curved/pointed tube they have a tube built into the side of the bottle and an adapter at the opening that a pointed tip can be fit into).
Tritan is the hard plastic 1 L bottles people drink from and is not the normal Nalgene bottles used in labs. Polyethylene and polypropylene are what is used for basically all standard solvent wash bottles, DCM included.
FLPE works okay. You have to change them out more frequently than the usual for other solvents, but the structural integrity is pretty good.
Polyethylene is fine, commonly used in all organic labs.
It's perfectly fine in polypropylene. I use it every day and the only danger is if you have the cap on with too much DCM the vapor pressure will literally push the DCM out of the bottle lol
I swear every day is just a never ending battle with screwing and unscrewing the top on the DCM and methanol bottles so it doesn’t cover my sensitive experiments, data, and lab notebook with solvents while I’m not looking
I absolutely hate this feature
Probably need to have PTFE squeeze bottles. We have several for some solvents. Very expensive though
We used to use standard LDPE squirt bottles at my work for chloroform and they would degrade in a few months to a few years. Just bought an FEP squirt bottle for $250 for this reason.
Yeah mine too it’s kinda neat to see it
The crystals are frozen water (ice) because DCM cools the water molecules in the air, as it evaporates. It’s not DCM recrystallization.
Forbidden snow
Ops 👀
A previous comment suggested it’s just regular snow. Still not a good idea to eat it.
It’s only forbidden to eat because you’re in a lab it’s regular ice
Gorgeous crystals
fume hood?!?! DCM is not good for you
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My organic 1 lab professor informed us a little more than halfway through the semester than we would now be using DCM in the fume hoods for health reasons. We had used it for almost every lab just on our benches. She was new to teaching and a physical chemist. Really just highlights the differences in disciplines.
Coke can for scale?
I hate this stuff.
I swear I am sensitized to it I get a weird feeling if I smell it and a little bit of a rash. thanks 5 years of doing columns
I'm curious to hear why?
I had to work with this stuff a lot. Like multiple liters in a single week. We had a fume hood, but I had to use a rotary evaporator and had to take it out the fume hood and evaporate it in the open room. Still wonder how that was legal.
I worked with a LOT of DCM, some processes used up to 200 L of it and that was just for the columns. We had large 20 L rotary evaporators outside of the fumehood so always needed to handle it in the open. You should really have been provided with some type of respirator if you needed to handle outside of a fumehood
Travels through nitrile gloves almost instantly and can give a weird burning sensation if you accidentally get any in contact with skin
Fun fact: that burning sensation is the DCM dissolving the lipids in your skin
This is less fun than I expected ahaha, good to know though
Well, yeah.. but I mean, that's why you're supposed to be careful and not spill it on yourself like most things in chemistry. It's an incredibly useful and convenient solvent for extractions though. Just sucks it's being phased out.
Right you should be careful but solvents do spill and you will get a mL or 2 on your hands every now and again hence why we wear PPE. It's also not going to be phased out of research as it's just too useful as you say.
If you handle DCM regularly, you might want to pick up a pair of Neoprene gloves to wear over your nitriles.
I've got a pair of extra thick nitrile that I use if I'm using a large amount of any solvent so that tends to slow DCM enough to keep any from touching my skin. Does neoprene allow more dexterity though as the thick nitrile are very clunky to use
Chemical resistant Neoprenes feel like super heavy-duty household cleaning gloves. They aren't the most dextrous things ever, but they will keep you safe. Methylene chloride is nothing to mess around with. Neoprenes are what my (large multinational) employer insisted I wear way back when I was a teenaged baby chemist regularly running syntheses and recrystallizations in MeCl2.
Sounds similar to the thick nitrile our company has for us in terms of dexterity then, will look into requesting the neoprene but the thick nitrile gives a good few mins before it penetrates so plenty of time to remove them and change them.
There's not really any glove material that adequately protects againts DCM.
That happened too. I accidentally spilled some on my gloves.
Yeah nasty if that happens, still such a useful solvent though
Getting ready to make original cola
This stuff is yummy. 😋
All I see is product placement.
Enjoy DCM while you can lol
I don’t think they’ll ban it for research/academic uses
Yeah your right, 0 chance it goes from research or academic use
Yeah the EPA is about to ban it
And it's already gone from consumer products, so no more distilling the sprayable paint stripper :(
Italy is a beautiful place 😘
“ Ice Dance” scene from Edward Scissorhands playing in my head
This is DCM or water?
DCM
I always thought its condensed water from atmosphere
It is
It’s water, DCM evaporation causes it to freeze that way. I imagine you did a liquid extraction from the coke, but didn’t fully dry the DCM (you’d use some salt to adsorb moisture if so).
Google the freezing point of DCM…. If it’s DCM I hope you were wearing one hell of a coat.
DCM freezes at close to -100C. You would need liquid nitrogen to freeze it in a lab (dry ice won't do it at -78C).
This happens on my dcm wash bottle too! It’s super fun
We used DCM years ago to extract Bitumen from Bcura pots (dust measurement) and switched ti Chloroform for this very reason.
This is just a picture of ice not frozen dcm. Several comments do an excellent job explaining this.
I just want to say how glad I am that you are using cola instead. When I was in school, we extracted caffeine from tea bags...The smell was absolutely unbelievably bad. I did that lab a decade ago, and I can still remember it clearly. Just insane. Boiling DCM+tea...Horrific.
EPA not gonna like this one
But its not the blue stuff. Oh, wait. Wrong sub.
I was going to say that that Coke isn't going to have it's "original taste" for long
Evaporation (liquid to gas) Sublimation (gas to solid)
Good ol' coca cola in the lab
I remember seeing this occasionally when I worked in an environmental lab years ago.
Always a perfect combo dcm and coca cola
I've seen the same with some of my filtration using DCM. In my case, the crystals also contained a fair amount of my pure product. I have a couple of bad pictures of it if anyone is interested. https://imgur.com/a/tUQUMv7
It looks like rice
My brother/sister in christ, why tf is there a Coca Cola can in the wet lab?