Aldrich: Proactive for Pyrophorics

Anyone ordered a pyrophoric reagent (butyllithium, DIBAL-H, Grignards, etc) from Aldrich lately?
Notice anything different?

For those new to the blog, I work at a relatively small biotech company, and as such do all my own ordering, from catalog lookup through payment submission. Last week, we required 100 mL of a soluble alkyl-aluminum reducing agent, so I made my order and waited for delivery. Instead, I got an email from Aldrich's Product Screening Team:

Greetings:  An item you've ordered is extremely hazardous. Please provide, at a minimum, a paragraph of how you will handle this material...

Whoa! Don't get me wrong, I'm all for enhanced laboratory safety, but we've ordered kilos of sodium hydride, liters of n-BuLi, and never encountered this particular safeguard.

When the aforementioned reagent (finally) arrived, it had the following label prominently featured on top:

"WARNING! The bottle inside this can contains a PYROPHORIC CHEMICAL. Exposure of this chemical to air as a result of careless handling or breakage of the bottle could result in spontaneous combustion of the chemical and extreme danger. This chemical should be handled only by trained, experienced and qualified personnel. Failure to follow the proper handling techniques could result in serious injury. Do not handle, transport or store the enclosed glass bottle unprotected!
     We strongly recommend retaining the metal can as a protective container for storing and/or transporting the inside bottle. 

NOTE -- Any literature included in this package must be read before attempting to use this chemical.      ALD-0056"

Double whoa! Now, I've been doing this a while, and I honestly don't recall seeing such strongly-worded labels on the outside. The label appears to be affixed a little differently from the standard product label below it, leading me to believe it's a recent addition to these product lines.

Somehow, I suspect that the increased safety precautions may have something to do with the ongoing legal battle out at UCLA.

Readers: Anyone from Aldrich read this blog? Can anyone weigh in here?

Update, 4/29: Since Andre asked so nicely in the Comments, I've included a picture, below:

Goodness, gracious, great bottle of fire!

Dirty Hood = Good Hood

Ever worked in a completely new chemical fume hood?

I have. Actually, due to moves and new facility construction, I've been (lucky?) to have three completely new hoods - hoods devoid of any smells, stains, or funny noises. All still had working baffles, legible installation labels, functioning flow meters, and bright white walls.

I ruined them all.

Chemjobber's latest post, referring to a "stinky walk-in hood," along with Pauling's lab notebooks got me thinking: How many times have I had to strip everything out of my hood, and start from scratch? I counted at least three; each one occurring in a beautiful, unsullied space.

In graduate school, I set up a sodium-mediated halogen exchange / rearrangement a few weeks after our move. After carefully flame-drying the apparatus, I greased and clamped all the joints, and set it to heat in an oil bath. I lowered the hood, and walked the ten feet or so to my desk...boom! We had a motley crew of older hot plates that didn't always heat up like you'd hope. Best I could piece together, there was an autoinitiation, followed by a massive exotherm I hadn't observed on smaller scale. Best part? After splattering my hood with compound, the flying glass cracked the oil bath, and little pieces of flaming sodium rained down around the pool of oil forming below my stir plate. Good times.
Total cleanup time: 3 days

As a postdoc, I had the "honor" of installing my own monkey bars, manifold, and otherwise arranging my virgin hood exactly as I pleased. Fast forward about a year, when I decided that a fairly exothermic borohydride reduction would go much better with a solid addition funnel. I'd covered all my bases - passive N2, massive cooling bath, flame-dried everything, the works! Except for one tiny variable: the borohydride particle size was too fine for the funnel's Teflon screw. One turn led to accidental addition of about half the reactant. Upon solution contact, the sudden gas release blew backwards into the solid addition funnel, which commenced to shoot a fine dust of borohydride onto every hood surface, including my arms.
Total cleanup time: 2 days

Later into my career, I had another heated reaction fail in stupendous fashion. The compound, a gummy orange solid, coated every surface of my hood: behind the sash, inside the light ballast, up the baffles, even down into the storage cabinets underneath. When I was finally done with that cleanup, my lab coat had been stained so thoroughly orange that we just bagged it and sent it out as waste.
Total cleanup time: 2 days

Look, all of these incidents would have been much worse if my sash had been up, or if I hadn't been wearing correct PPE when they occurred. We think about fume hoods as big vacuum boxes, but they're also great for containment of runaway reactions.

Readers: I know I'm not alone. Have a spectacular story of a reaction gone wrong? Share it in the comments.

Houston, We Have 'Level A' Protection

We just wrapped up our annual HAZWOPER training, and I've always bemoaned that it's all Powerpoint and quiz questions, without enough "hands-on" activities. Well, that certainly changed this year!

Although I'm a bit late for Lab PPE Day (this isn't really a lab setting anyway), this was my first time in a Level A suit. Wearing this feels exciting, but mildly disorienting: it's like walking through heavy snow, with both dexterity and visual impairment.

Dressing up this way gives me an even greater appreciation for everything the astronauts are able to accomplish in NASA space suits. Alas, although we tested spill kits, used gas meters, and drilled placards, freeze-dried ice cream was not served.

Stay safe, everyone!

Dirty Jobs: Why Don't Chemists Wear Suits?

“Clothes make the man.” – Mark Twain

For every occupation, a mark: grass stains on athletes’ socks, tar for roofers’ pants, or grease on mechanics’ smocks. But has Mike Rowe, host of Discovery Channel’s Dirty Jobs, donned a lab coat lately? Synthetic chemists work every day with substances other people use to dissolve metals, dye fabrics, or kill microbes. Naturally, we end up wearing some of it by the end of the day.

R.B. Woodward: Suit or bust!
Credit: nobel.se

A long-standing joke among bench chemists: you can tell a lab visitor straightaway . . . because they wear nice clothes! Looking at pictures of scientists from a few generations ago, one wonders why they chose to dress so sharply for an inherently messy, hands-on occupation: in the days of R.B. Woodward [1965 Chemistry Nobelist], de rigueur lab wear was a 3-piece suit, tie, and (maybe) a smock. Goggles or gloves weren’t strictly required. The counter-cultural ethos of the following scientific generation eschewed formal dress for button-downs, khakis, loafers, and lab coats, a change which may also have been driven by old-timers’ tales of neckties stuck in stirring rotors or acid-eaten sport coats.

Today, synthetic organic chemists just don’t wear really nice clothes, because they won’t stay that way for long. In every corner of the lab lurk wardrobe-destroying substances.

Color Changers - Nitric acid, hydrogen peroxide, and sodium hypochlorite – all strong oxidizers – leave dark-colored clothes with bright white or yellow marks. Solvatochromic effects, color changes brought on by solvent interactions with fabric dyes, show you shades you wouldn’t expect: green shirts can turn yellow, blue shirts turn purple, and yellow shirts appear orange. This tinge luckily fades over time as the solvents evaporate.

Mechanical equipment brings other laundry challenges. Grist and grime from high-vacuum pump valves stains blue jeans dark brown. Corroded metal clamps produce dark rust streaks. Silicone oil, a lubricant for glass joints, saturates fabric, leaving dark spots that look permanently “wet.”

It’s not just appearance under attack: ethanethiol, the odorant most people associate with gasoline pumps or natural gas leaks, leaches into hair and clothes, leaving a persistent sulfuric smell.

Indelible Metals - I once made a bright yellow ruthenium hydride complex, a trace of which spilled on my dark green T-shirt. No matter how many times it’s been through the wash, the compound stays firmly stuck in the fabric. Ditto dark orange stains from nickel complexes set into my white lab coat. Khaki pants develop purple-brown stains from silver complexes or iodine. Perhaps spills like these gave chemical company Johnson Matthey the idea for FibreCats, catalytic metals immobilized on fibrous strands for easy recovery.



Much closer to real life!
Credit: test-tube.org.uk



Scorched Shirts – Ever spill concentrated sulfuric acid on cotton? You won’t know until the spray-pattern of tiny holes shows up after washing and drying on high heat. Since cellulose and sucrose are both sugar-based, perhaps this is the clothing equivalent to the black carbon snake general chemistry demo. Be especially careful with that bottle of nitric acid; one of the first synthetic explosives, nitrocellulose or “gun-cotton,” was made accidentally in the early 1800s as cloths used to clean up spills would explode suddenly when left to dry.

Some pertinent advice for those who wish to look good in lab? Find a good dry cleaner.