Sodium Ball of Death

An interesting problem encountered by wafflesforlife on /r/chemistry.

I recently inherited responsibility for the solvent stills in my lab and, even more recently, had to quench, clean and reset our THF still. I used a standard sodium-benzophenone system and was happy to see a beautiful purple color when all was said and done. Now, after several uses of the still, the sodium has clumped into a giant ball (2" in diameter) and floats around in the still, even at room temperature. The exposed sodium still appears fairly metallic and the still has maintained its nice purple color. However, my concern is that the exposed sodium no longer has a THF "buffer" surrounding it and could be more reactive towards any contaminants that could get introduced. Also, I figure with roughly half of its surface area out of the solution, the sodium will not be as effective at drying the still. Has anyone else encountered this problem? After such a short period of time, I would rather not go through the trouble of quenching and setting the still up again, but maybe I just need to sack up and do it for the good of the group. Any advice would be appreciated!

Taken from: Floating sodium ball in THF still. Is it safe?

Mitch

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Stories from a Chemical Hygiene Officer

A Guest Post today from chubscrubbins.

First, my background. I am not a Chemist. I was hired as a "chemical safety specialist" to basically administer lab inspections and run the stockroom. My previous military experience as a Nuke helped me greatly when it came to getting my job. My position evolved to Chemical Hygiene Officer for the College of Science and Engineering, then to Radiation Safety Officer for the University, and eventually to a Environmental Compliance Auditor for EPA Region 6 private schools.

1. My Scariest Moment

When a package came into the stockroom, I checked the DOT labels to determine how to open the container. It was too cumbersome to open everything in the hood, so if it had no labels I just opened it on the receiving table. On a particular day, like any other, a single package came in. No labels. I put on my nitrile gloves and opened the container. I removed a small bottle nestled in Styrofoam and immediately noticed that my glove was drenched. Annoying. It happens. I look at the bottle and I immediately lose my shit. The first word I see is Dimethylmercury. I had taken lab safety classes and was aware of the tragic death of Karen Wetterhahn. My mind was racing. My wife was pregnant and hadn't finished grad school. What if I died and wasn't there to raise my child? Awful thoughts ran through my head.

I took off my gloves and placed them into a secured waste container. I calmed down and walked to our most experienced Organic professor and told him what was happened. His jaw dropped and he muttered, "Fuck." We walked to the stockroom and I showed him the container. I saw relief in his face, which then turned to anger. The substance was a standard used by the biology department for a mercury analysis machine used to determine Hg concentration in fish. I believe it was either a 1ppm or 1ppb standard. I really can't remember. I thought he was pissed at me for overreacting, but he was really mad at the professor who ordered it. Never understood why. Either way, I left work early to be with my pregnant wife and wind down.

1. Most Embarrassing / Saddest Thing I Witnessed.

I was actually taking Organic Chemistry Lab to improve my practical chemical knowledge. We were performing an extraction using dichloromethane. Nothing fancy. There was a real dunce in the class who had horrible lab technique. It was obvious from the first lab. The dunce went to pour his organic layer back into his sep funnel, but forgot to close the stopcock. In addition, he was doing this outside of the hood with the glassware aimed right at his crotch. After drenching his genitals with dichloromethane, he stood at his hood, too embarrassed to move. I heard him go up to the TA and say, "I think I messed up." By this point, his penis had started itching and burning and he was really worried. I brought him down to the stockroom and had him strip down to his boxers while he stood underneath the safety shower. I made him stand there for the whole recommended 15 minutes. Sadly, the professor in charge of the lab heard about the accident and came in and bitched him out as he was standing there in his boxers. I felt awful for the kid. He dropped the class the next day and switched majors. I don't think he was cut out to be a chemist, but I still felt awful for how he found out.
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What is that thing? The new GHS symbol for carcinogens

The Globally Harmonized System of Classification and Labeling of Chemicals (GHS) is the new international standard for shipping and labeling chemicals so that their hazards are communicated in a logical fashion. Since we're now in a globalized commerce system, where (for example) Aldrich sells chemicals all over the world , GHS creates a single standard for how different hazards (physical, health, environmental) will be communicated to shippers and receivers.

So if you look at the new symbols, they're all pretty boring. I feel like the skull on the "toxic" label is just a little bit different and the dead fish for the "environmental hazard" is a little graphic, but gets the point across well.

But here's my question -- what's this label on the right supposed to communicate? Any guesses?

That is the new GHS symbol for carcinogenicity. While I understand that you can't write "HEY, DUMMY! THIS WILL GIVE YOU CANCER" in fifteen different languages, I feel that this thing that looks like the T-1000 after being hit with a shotgun will just lead to confusion in all parts of the world.

I shouldn't criticize and not offer a better solution, but I'm not positive that there is one. It's such a difficult concept to attempt to communicate. The broken double helix motif of the cancer hazard sign is aesthetically pleasing and logical, but it requires an understanding of basic molecular biology that Starman this symbol doesn't require.

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Sigma-Aldrich: "All-U-Can-Eat" styrofoam with every purchase!*

*Substitute for weird grey flaky stuff at no extra charge!

Hi, everyone. Apologies for my absurdly long absence from the blog--I've been extremely busy hammering out an enormous project and writing grant applications to the Canadian government for the past few months.

Today's post is going to be a short one, but it's a problem that's been vexing me for the entire time I've been at grad school. As the person at my lab who is charge of ordering reagents, and partially responsible for the inventory and cataloging of them, I get to see first-hand how much packaging goes into a Sigma order. I think I can speak for everyone when I say that the policies they use for determining "adequate packaging" are absurd to the point of being humourless (figures 1 & 2).

Figures 1 & 2. This is a 25g bottle of 1-decyne that we received today from Sigma, shown for scale with the size of the box and the amount of styrofoam used to ship it. This is far from the worst case of overpackaging I have seen.

Now, I understand several things:

1. These are indeed hazardous chemicals (sometimes)
2. A breakage or leak in transit would be a "non-trivial" (cf. dangerous and embarrassing) problem
3. The company is responsible for making sure that I receive the items intact and in perfect condition
4. There are numerous regulations regarding the transport and handling of these materials, both domestically and across international borders

HOWEVER. When receiving items from Strem or Alfa, the packaging isn't nearly as excessive (that is, they usually ship multiple items individually wrapped in a single box, unlike Sigma, who generally place a single item in a single box for an entire order, unless there are a series of similar items, such as various 500 mg bottles of pybox ligands). Both Alfa and Strem ship from the U.S., so I know that it isn't simply a border issue, and indeed, when things get shipped to us by Sigma from Oakville, Ontario, the reagents are still swaddled in enough layers of plastic pillows, styrofoam, grey fabric, or that weird flaky stuff to survive getting thrown out of an airplane. I've received orders where individual 1g bottles of reagents are packed in their own boxes, resulting in an entire garbage can full of packing junk after ordering only 5-10 g total of actual materials.

It may be a funny coincidence that I work in a "green chemistry" oriented laboratory, but all comedic weepiness aside, this packaging offends me every time I make an order. The amount of styrofoam alone that goes into the garbage here every week could probably fill a hot tub, and that stuff never goes away. I've found an aftermarket use for the grey fabric, and the boxes can be recycled easily, but the rest of it just goes straight to a dump.

So, I pose these questions to fellow chemists and other scientists in the States:

Does Sigma-Aldrich use the same asinine packaging policies when shipping domestically?

Does it enrage you, having to swim through a sea of styrofoam just to find your starting material?

Do you fantasize about sending back the box-o-styrofoam with a note encouraging them to re-use it?

Do you fantasize about collecting a year's worth of Sigma-foam and filling your swimming pool with it?

What is that weird greyish flaky stuff?

Nick

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CSB Releases Sheri Sangji Video and Other Stories

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High School Pressure Demonstration Injures Student: What Was the Instructor Thinking?!?

As linked over on the Chemistry Reddit, there's sad news from a suburban Chicago High School to report.  A 16 year old student at Richard High School in Oak Lawn was severely injured during a pressure demonstration when the apparatus his high school chemistry teacher was using to demonstrate increasing pressure failed.

Get this: the teacher allegedly put dry ice and some water in a plastic bottle, then tightly closed the lid.  Then, allegedly he actually passed the bottle around the class so students could physically witness the buildup of pressure.

Dumb. Dumb. Dumb.  Honestly, what was this chemistry teacher thinking?  Apparently the students may not have even been given goggles to wear.

Who knows how many years the teacher has been doing this demo serendipitously without incident.  Well, this time the bottle exploded while this student was holding the bottle.  He can no longer see out of his left eye, and he suffered hearing damage and other injuries to his hands and face.  It's unclear from the reports if he physically lost the eye or lost his sight in that eye.  The teacher is on administrative leave and the parents of the boy have filed suit.  The parents are claiming "negligence, willful and wanton misconduct and vicarious liability" and are seeking more than $150,000 in damages.

Now, I've worked with pressurized dry ice before.  For those of you who don't know, dry ice is solid carbon dioxide.  The solid carbon dioxide sublimes to gaseous carbon dioxide at room temperature and quickly becomes a gas with a volume much much larger than the original solid.  If you put all this volume in a closed container, the pressure will build and build until the container fails and explodes.  You make a bomb as soon as you put dry ice in a closed container.  The addition of water accelerates the sublimation causing the pressure to build up faster.

I've done this demonstration before at 'magic shows.'  We used a small amount of dry ice in a 2-L pop bottle.  We were outside, we had the kids and team members a good 30-40 feet away behind a fence, and we covered the pop bottle with one of those plastic mail crates to absorb the force of the exploding bottle and contain any shrapnel.

It's really loud.  Even with the mail crate atop, the explosion still throws the bottle/crate 5-10 feet in the air.  There's absolutely nothing safe about this demonstration, and there's no reason to have anyone anywhere near the bomb while the pressure is building.  ESPECIALLY don't have teenagers play hot potato with it!  Geez!

I also blogged a while ago about using liquid carbon dioxide as a green extraction technique.  To create the liquid carbon dioxide, you need to change the temperature and the pressure.  Put some dry ice in a plastic centrifuge tube, cap the tube tight enough that the pressure builds, but loose enough that the gas can still escape through the threads, and submerge the centrifuge tube in warm water.  The authors of the paper suggest the carbon dioxide inside the centrifuge tube approaches the triple point as it is converted into a liquid.  The triple point of carbon dioxide is  -56 degC, and 5.1 atm (the critical point is 31 degC and 72 atm).  5.1 atmospheres is still a big deal, and letting the gas buildup escape through the threads of the centrifuge cap is crucial to maintaining some semblance of control over the setup.  I still got admonished in the comments to that post about the safety of the extraction and the setup I constructed.

Bottom line: there is no reason to callously put dry ice in a closed container.  Just don't do it.  It really does make a bomb, and bombs really do destroy things.  It's just not worth it.  In fact, making a dry ice bomb is illegal in most jurisdictions.  As one Reddit commenter noted: "this is one of those experiments where a YouTube video will suffice."

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Cheap Laugh Tuesdays #4: The Fume Hood

Welcome back to Cheap Laugh Tuesdays (CLT)!

See other CLT humor

via PhD Comics

Enjoy!

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Casey Anthony and Chloroform: How Does It Work?

Much of the country was all caught up in the Casey Anthony trial over the past few weeks as the testimony concluded and the verdict was announced (full disclosure: I was not at all caught up.  I didn't even read any articles about the trial until after the verdict was announced).  If you want background on the trial, wikipedia's as good as any in this case.

One of the points raised during the trial was whether or not a Google search was performed on How to Make Chloroform.  One way to make homemade chloroform is by reacting household bleach with acetone.  Whether or not the search was performed or for what reason, and whether or not anyone involved in this case actually tried to prepare homemade chloroform is irrelevant.  We're going to talk here about how the process works from a chemical and intellectual perspective (full disclosure: This will NOT be a how-to post on how to prepare and purify chloroform.  That information can be found elsewhere).

Safety First:  Nearly all the chemicals involved in this process are dangerous and need to be handled with caution and respect.  Bleach is a solution of sodium hypochlorite in water, usually containing a small amount of sodium hydroxide (lye) and/or sodium chloride.  Sodium hypochlorite is a strong oxidant and will cause severe burns when concentrated (it is generally safe for low level exposure when dilute as in household bleach, but will still discolor skin and clothes).  Sodium hydroxide is a strong base and will cause severe burns (think Fight Club).  Acetone is generally safe when used as indicated, and it is commonly used as nail polish remover.  Careful, though, it can dry out the skin.  Chloroform itself is a suspected carcinogen and can cause dizziness and fainting.  Also, if this process is done incorrectly, the byproducts can be quite dangerous as well.  Bleach mixed with the wrong ingredients (like vinegar - don't mix your bleach with vinegar!) can produce chlorine gas - a highly toxic gas that no one should want to be around.  Chloroform will decompose on exposure to oxygen to produce phosgene - a WWI chemical warfare agent.  Needless to say, do not try this at home.

General procedure: To make chloroform, acetone is mixed with either sodium hypochlorite (bleach) or calcium hypochlorite (bleaching powder).  This is a highly exothermic process releasing a lot of heat.  The reaction is generally cooled by submersion of the reaction vessel in ice-cold water or by directly adding ice to the reaction mixture.  The acetone is oxidized by the hypochlorite to form chloroform, with sodium (or calcium) acetate as a byproduct.  The chloroform needs to be purified and stored away from light by processes not discussed here.  The general reaction is as follows:

Three molecules of sodium hypochlorite react with one molecule of acetone to produce one molecule of chloroform, two molecules of sodium hydroxide, and one molecule of sodium acetate.

How it works: The mechanism for this reaction generally follows the mechanism of the haloform reaction: a classical organic chemistry reaction whereby a methyl ketone (acetone is a methyl ketone) reacts with a halogen (Br₂, Cl₂, or I₂) under basic conditions (NaOH) to produce a haloform (bromoform: HCBr₃, chloroform: HCCl₃, or iodoform, HCI₃).  Iodoform is a pale yellow solid that is insoluble in water.  For this reason, organic chemists have developed what's known as the iodoform test.  Aqueous solutions of unknown compounds can be treated with iodine (I₂) and sodium hydroxide.  If a yellow precipitate forms, this is a positive indication that your unknown has a methyl ketone.  This is the general scheme for a haloform reaction involving chlorine (Cl₂):

The mechanism (below) for the classical haloform reaction is quite clever.  We need to break one of the carbon-carbon bonds to liberate chloroform from acetone.  As organic chemists, we're always so concerned about how to make carbon-carbon- bonds that we rarely think about breaking them.  To begin, in step 1) the base, sodium hydroxide, deprotonates the mildly acidic proton on the CH₃ group of acetone, forming a resonance-stabilized enolate intermediate.  In step 2) This enolate intermediate becomes monochlorinated by reacting with one molecule of chlorine.  By repeating step 1) and step 2) two more times, one side of acetone becomes trichlorinated.  This is a favorable process.  In step 1), the base was deprotonating a mildly acidic proton.  After each addition of chlorine, the acidic proton becomes more and more acidic, making the deprotonation easier and faster each time.

In step 3), the sodium hydroxide acts as a nucleophile and attacks the central carbon atom, causing the carbon-oxygen double bond to break into a single bond resulting in a negative charge on the oxygen atom.  Oxygen would rather have a carbon-oxygen double bond than a negative charge, so in step 4), the carbon-oxygen double bond reforms, and the anion Cl₃C^- is released from the molecule.  Typically, carbon is rarely released from a molecule, as a carbon with a negative charge is very, very unstable.  Because of the three, electron-withdrawing chlorine atoms attached to carbon, the negative charge is stabilized and the carbon anion can easily be released from the molecule in step 4.  As a byproduct of step 4, the carboxylic acid acetic acid (vinegar) is formed.

One more step is needed to finish the mechanism for this reaction, and it is also the final step in forming chloroform.  While the carbon anion is somewhat stabilized by the three, electron-withdrawing chlorine atoms, the carbon is still unhappy having a negative charge.  All things considered, generally carbon would like to be neutral, not negatively charged.  In step 5), the carbon anion acts as a base and deprotonates the acidic proton on acetic acid.  This forms chloroform and sodium acetate.

This is not exactly how chloroform is produced when you use bleach, but the process is very similar.  There is often a small amount of sodium hydroxide in household bleach to help with the initial deprotonation, and the sodium hypochlorite is the source of chlorine.  For the traditional haloform reaction, you must use chlorine gas as one of your starting reagents.  Using bleach allows you to work around using the highly hazardous chlorine gas (not that the bleach process is much better).  In general, the acetone and bleach react to sequentially place three chlorine atoms on the terminal carbon atom of acetone.  That carbon atom then fragments from acetone as the trichlorinated carbon anion, which picks up one hydrogen atom in an acid/base step to form chloroform.  I'm not sure exactly what the intermediates look like in the bleach mechanism, but they will be generally similar to the classical haloform mechanism.

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Officials on House Full of Explosives: "Let's Set It on Fire!" - Updated

WATCH LIVE!

Several local tv outlets will be live streaming (did stream) the controlled burn at 9am pacific time (noon eastern) 11am pacific (2pm eastern).  I'll be teaching class at that time, so someone let me know if it's uneventful or, er, eventful.

NBC

CBS

ABC

FOX

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On November 19, a gardener for Escondido, CA, resident George Djura Jakubec was walking in the backyard when he stepped on something causing it to detonate.  The explosion caused burns and abrasions up one leg, under one arm, and on his head and eyebrows, and he was hospitalized.

Officers started searching the yard and home... then quickly retreated when they found numerous explosive compounds and explosive-making materials in and around the house.  According to various reports, items found on the property include:

• 9-12 pounds (4-6 Kg) of homemade HMTD, PETN, and ETN (which authorities claim may be the largest discovery of its type on US soil...)
• 13 grenades
• 9 detonators
• bags of metal pieces and ball bearings
• semiautomatic weapons
• several gallons of nitric acid, sulfuric acid, hydrochloric acid
• 50 pounds (23 Kg) of hexamine
• books about explosives
• a tracker hidden in currency during bank robberies

And then they decided to call off the search because the house was too unsafe for offices.  Who knows what else may be in un-searched corners of the house.

Not surprisingly, Jakubec, a naturalized US citizen originally from Serbia, is in jail on $5 million bail and is charged with more than 25 felonies relating to explosives and bank robbery.  He pleaded not guilty.

Officials say there is no safe way to remove all the explosives from the house, so the best way to neutralize the danger is to burn the house to the ground.  They plan to evacuate 200 homes, build temporary fire-safe walls between the house and its neighbors, spray the wall and neighboring houses with fire-retardant foam, pre-heat the house so it ignites quickly, then start a fire.  They plan to wait until a time after morning rush hour when the winds are calm before starting the fire.  They will need to close part of nearby interstate 15 because of the house's proximity to the highway.  Gov. Schwarzenegger has declared a state of emergency for San Diego County.

Yikes.

Update (12/4): The North County Times is releasing images taken from inside the house.  Very disturbing.   Very disturbing indeed.  It's like that one episode of CSI where almost the exact same thing happened.  They're clearing the house, when the one CSI opens a fridge in the garage.  Then he slowly says to the other CSIs in that low, dramatic tone of voice. 'stop what you're doing and slowly walk out of the house.'  They ended up doing the same thing to that house, only they detonated the explosives and esploded the house instead of lighting it on fire.  Click the image for all 12 pictures.

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News Stories:

• 11/21 story on initial searches of house
• 11/23 story on suspect and house searches
• 11/24 story on family history of suspect
• 11/30 story on decision to burn down house
• 11/30 story on execution of search warrant and list of items found in house
• The search warrant
• 12/2 story on preparations to community for burning down the house
• 12/2 story on safety preparations being taken before burning down the house

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Lab Horror Stories

After Jyllian Kemsley's story on the non-supervised cavalier graduate student and his missing fingers, members of the chemistry reddit shared their own harrowing experiences around the lab. I would suggest we all try to learn something from these stories, the most important lesson being always wear your safety glasses!

bri1232001:

I work in a chemistry lab and last week an intern was involved in an accident. The intern sealed a glass vial with water and dry ice inside. The vial exploded and glass shrapnel gave him multiple lacerations on his face and arms. He was taken to the emergency room where he received stitches. His safety glasses had some extensive chips removed from them. He was very lucky to have had them on.

myarlak:

I saw someone get 2 large drops of sulfuric acid on their arm, and the acid ran down their arm about 4 in. they now sport scars that look like something with large fangs bit their arm and ripped... I personally have been sprayed in the face with phenyl Grignard, not horrible but burns when it gets on you, burns when you wash it off. I saw a gas tight syringe full of diethyl zinc lose it's gas tightness, caused a small fire and that was it. I saw the results of someone leaving lithium open in a glove box... melted through one layer of steel and bowed the 2nd layer as it burned in nitrogen... that's about it, mostly a bunch of close calls.

simplemathtome:

two postdocs were working in the glovebox next to me. They spilled some MeLi and were mopping it up with kimwipes. They knew it would be dangerous when they pulled it out of the antechamber, so they prepared an EtOH bath (which, to be fair would safely neutralize a small amount of MeLi, iPrOH would have been better). One postdoc opens the antechamber and, as quickly as possible, took the kimwipes out and dunked them in the EtOH bath, only problem was, the kimwipes burst into flames as soon as the kimwipes were exposed to air, setting the bath on fire. In the panic, one of the postdocs went to get MORE ETOH and poured it on the fire. The bath overflowed, she started yelling for liquid nitrogen, I got out of my box and started running towards the liquid nitrogen. The next thing I know, i hear screaming, the postdoc walks out of the lab (right under a safety shower, without pulling the water release) with her entire pantleg on fire. I cant find LN2 so I take off her labcoat and snuff out the fire on her leg. The other postdoc managed to put out the EtOH fire, but he didnt remember how he did it. They both went to the hospital, one of them stayed for 2 weeks. That was my first summer in a lab, right before sophomore year.

sprouts42:

Teaching a group of 13 year olds a few months ago showing them the decomposition of limestone and running the gas through limewater to show carbon dioxide. You have to get the limestone really hot in a boiling tube using the bunsen. After the practical was over I told the students to turn off the bunsen forgetting to tell them to remove the delivery tube from the limewater. Almost simultaneously the sound of limewater rushing up the delivery tube into the boiling tube and causing it to explode 15 times over. Screaming girls all over the place and glass showering everywhere. Another safety glasses save the day moment.

shyguysays:

When I was in organic lab, my TA closed my heating reaction flask a little too tightly. It blew up. I pulled three pieces of glass out of my forehead right above my right eyebrow. The stopper hit my partner in the head. We lived long enough for the department to let us graduate.
Yay for goggles!

theddman:

My lab neighbor (synthetic organic, read: the jocks of chemists) was running a huge silica column that burst all over him because his girlfriend was distracting him. He had to use the emergency shower!

Same lab neighbor blew up another column or something with concentrated TFA in it, he has a few cigarette-looking burns on his arms from it.

I personally was making some 10 M NaOH in a conical 50 mL tube ("Falcon" tube) early in my career. I added the pellets and the water, closed the screw cap tight and shook vigorously to dissolve it. Well, of course dissolving NaOH in water is highly exothermic. Yep, the entire thing blew the eff up and got NaOH all over me, my bench, and even the ceiling. Luckily I didn't get burned anywhere important because I was wearing safety glasses.

I overfilled an ultra filtration device with very VERY expensive compound, lost half into the centrifuge rotor. Effing pipetted that shit out and HPLC purified it (shhh, don't tell the boss!).

I could go on and on...labs are filled with dangerous things and overly curious hands.

thelt:

Last year in our lab we had a 4L waste jug of Piranha (3:1 conc. H2SO4:conc H2O2) solution explode, actually more like geyser, all over the lab. Thankfully no one happened to be in the lab otherwise they would have been fucked. Pretty much everything within about a 10 ft radius of where the jug was destroyed. The paint peeled off the walls and ceiling, lights had to be replaced everything. Hazmat team had to be called in to clean up the mess. For about the next week or so I couldn't stand to be in the lab for more than about 20 minutes or so before my throat would start to burn.

Note: When storing waste piranha don't cap the bottle.

smilingfreak:

Well, I'm a comp. chem, so there was that one time I spilled coffee on my lap. It was like, really, really hot.
Yeah.

Screw you all! I'm a real chemist! Honest!

erallured:

I worked in the stockroom in undergrad and was unsupervised a lot, especially in the summer. I was messing around and made some NI3. I knew it was really unstable when dry, so I took just a spatula tip of it out of the beaker and spread it on some filter paper. It couldn't have been more than a milligram or two. I was working in a fume hood in an empty lab away from anyone else. I kept pressing on the thin streak of powder trying to set it off but it wasn't going. I decided maybe I didn't have enough/it was too spread out, so I was going to add some more. I used the spatula to move the paper slightly, and apparently it had dried and this small movement was enough to set it off.

¡BOOM!

I was instantly deafened and after a couple seconds had a loud ringing in my ears. A few seconds after that, a research student opened the doors and walked it. She said something to me, but I couldn't hear so I just said "hi" and smiled, hoping she was just greeting me. She walked away with no indication she knew anything was up and gradually my hearing came back. I have no idea how she didn't hear anything, she must have only been a few feet from the lab door when it happened. I was so shaken up, I dumped the rest (I had a good 5-6g of precipitate) into a waste jar and got out of there. All in all, not the worst, but for a few minutes, I thought I'd lost my hearing permanently.

DessicatedDogsDick:

A guy in my lab was cutting titanium sponge off an electrode (molten salt process) when it caught fire. There was probably around 2 kilos of the shit that went up in a very large, hot fire. He emptied two CO2 extinguishers onto it, which only made it worse. In desperation, he picks up the metal tray it's sitting on (still burning) and bolts outside. The tray melted through just as he reached the door. The lab bench and stuff around were basically ruined from the heat.

zlukasze:

I was adding "dry" ether to stannic chloride, prepping to make tetrachlorobis(DMSO)tin(IV).S omeone had mislabeled the ether, and it apparently had a very high water content because the lab promptly filled with hydrogen chloride gas and shrapnel. The space abutted some department offices and they had to be evacuated.

Farrar:

There was a pretty bad one where someone had to go to hospital; they were pressing the bung onto a conical flask, when the glass smashed. Because of how they were holding it, a rather large piece sliced up their arm, slashing open their wrist and it required quite a few stitches.

There was also an incident where an evaportating dish exploded and it cut open atleast three students, but luckily those were only minor surface injuries.

Oh, and one where someone ate some copper sulphate and had to have their stomach pumped...but that's more of a 'don't be so stupid' rather than a horror story...

calladus:

In high school chemistry class, way back in '81 or '80. Due to budget problems, the chemistry teacher was let go and the job was given to the woman who usually taught English. Class was pretty boring - very few experiments, mostly reading and explanations of what "ought" to happen when this is mixed with that.

But there was one experiment with mercury that she wanted us to do. So she went into the chemical storage area, and came out with a container of mercury. It was a very heavy container - well over 20 pounds. She dropped it.

Mercury ran in little balls all around the classroom. To fix it, the teacher gave us all 5x9 index cards and had us scoop the mercury together to the middle of the classroom where she swept it all up with a broom and dustpan and returned it to the container.

When everything was "cleaned up", we all continued with class. The container of mercury was put back into the chemical storage area. As far as I know, she never mentioned this to the principle, or anyone else..

barrysagittarius:

I worked two years in an Organic Lab and two years in a Chemical Physics laser lab. The worst two to strike me were: - In my organic lab I was putting glassware in some basebath and the flask dropped from my tongs. As it sunk, the air escaping splashed bath into my face. Some minor scars on my forehead and thank god for my safety glasses - In my laser lab, i passed through the beam path; a common practice since the laser is focused - usually - inside the reaction chamber. However this time, one of the beams was focused outside and I brought my hand through it. I still remember the SNAP sound and the burning feeling inside my hand. Much fun.

The worst things happened to others in my lab. I spent a summer making precursors for this very lengthy organometallic compound we were making. One of the reactions was to bromenate a compound and was HIGHLY reactive - I was adding the bromine solution dropwise while the target flask was at -5C and it still fizzled with each drop. Anywho, after the reaction, it had to be quenched and washed with ether. After I did this on a 100mL scale a couple times, the grad student I was working with decided to try and scale it up to 1L (...). I was out the day, but when I came in the hood was brown. And the floor, and the ceiling, and... and we had much less glass ware, including the entire glass vacuum line. Apparently he didn't completely quench it, and with one shake in the separation flask (can't remember the name, been a while) it exploded. Horrible chemical burns and stiches later... he was back at it a week later.

The second worst thing was my laser lab. Me and a grad student were building an electron gun from spare parts for an experiment. We had to hack together the power feed into the vacuum chamber, so it was just a flange with a bunch of copper leads. To power the gun, we used these flimsy connectors we had to clip on and off the leads (until we got the final connectors in). Oh and our Power Supply was 10kV floating (in a lucite box ). Well, again, I was out sick, and my grad student got his thumb too close to one of the leads and WHAMMO! 10kV to the chest; blown across the room into a wall but otherwise okay.

relampaguear:

At first here, I must confess this happened to my lab partner and not myself. I work in an organic lab that does a lot of solid phase peptoid synthesis, and after the desired residue length is reached, we cleave the peptide from the resin using TFA. My lab partner was using a 10 mL syringe to measure the aliquot needed and pulled the stopped out all the way, splashing concentrated TFA all over her face and arms. Thankfully the only lasting casualties were her goggles and a gnarly scar above her eyebrow.
Go goggles go!

abyssuk:

I used to work for a major peptide synthesiser in the UK. The worst part of a peptide SSPS (solid state peptide synthesis) reaction is the cleaving of the peptide at the end from a silica bead basically. Most times this can be done with TFA but for some more difficult peptides you need to cleave with 99% HF gas cooled to a liquid with solid CO2 pellets in polypropylene flasks. All contained in specialist equipment from pressurised cylinder to flask in a fume hood. . I'll stress now It wasn't me who did this.. but once the poor soul who was doing the reaction couldn't open the HF cylinders valve because it was rusty.. so hit it with a hammer!! The valve broke off and the HF gas started venting out to air very quickly. The whole building was evacuated very quickly and the fire brigade was called out, luckily nobody was hurt as the hood vented most of the gas out of the building. Afterwards once the fire brigade deemed it safe the damage to the fume hood and roof of the building looked like that scene in aliens.

pfschmit:

I was making a catylist using LiAlH4 and reacting it with a diglycol, not realizing a byproduct was H2O. I soon found out when the temperature went through the roof and a explosion followed. Fortunately, I had a blast shield in fromt of the flask. Nice fire though

palad:

In high school, our chem instructor warned us very clearly about the flammability of acetone. So naturally, my lab partner and I wanted to see if our teacher was correct. On the last day of a week-long lab, after everything had been cleaned up, we filled a small beaker with acetone and carefully placed it in one of the deep sinks. As I lowered the lit match toward the mouth of the beaker, I failed to notice the puddles of acetone spilled on the tabletop moments before by other students. One giant WHOOOSH later, and we had the attention of every student in the room, including those 30 feet away who claimed they felt a wall of heat blow past them. Fortunately, the acetone was the only thing flammable nearby, and it quickly burned itself out.

When I got home that afternoon and looked in the mirror, I started wondering why some of my hair had changed color. As I touched it and it flaked away into ashes, I realized just how close the flames had come.

merlin2112:

Around 12 years ago, I was given the task of preparing Azomethane. No, not Diazomethane, but Azomethane. This was to be used on the surface of Pyrite via FABMS. Anyway, the procedure called for: dimethyl hydrazine NaOH H2O Mercuric Oxide Following a reference (see Surface Science(279)79(1992)) the procedure is fairly straightforward; the problem lies when You have to evaluate the solid Azomethane to determine if any color is present.

After making ~25gm of Azomethane a normal procedure was called when I had to wipe off the frozen vacuum tube. POP! The tube exploded, giving Me lascerations to my hand, side of my face, and shattered my glasses, which gave Me a lascerated cornea!

Luckily all glass was removed and I was back in the lab after 7 days recovery making Azomethane again!

Mitch
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(Visible) scars of chemistry

Mitch's post showing the video of "the mark of the chemist" reminds me of one of the most visible remembrances I have of graduate school: the scar on one of my middle fingers (see left.)

On a lovely Saturday in the lab (my music playing, no one else around), I dropped a Dewar flask from a shelf onto the lab bench. Along with the pop that announced its destruction, I saw that my finger was bleeding. My adviser brushed off my protestations that I was fine with "[CJ], you're bleeding all over the floor." He was right and off I went to the campus health center.

It's been at least 6 years since I've had the scar. It's healed, but left the interesting black mark that you see and a lump that I suspect may be embedded glass. But when I think about chemistry and potential dangers that I could face, all I have to do is look down at my hands.

UPDATE: The Curious Chemistry Grad Student shows off a couple nice burns.

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Dangerous Chemistry Sets

From: SMBC - Fear Itself

~Mitch

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