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.