9 Worst Lab Smells

A thiol is an organic sulfur compound. A familiar example is the rotten egg smell of hydrogen sulfide. Compounds with the S-H group tend to be toxic as well as smelly. As an added bonus, if you work with one of these compounds, the odor tends to "stick" to you and your clothes, emanating from your skin even after you bathe. It's not a perfume likely to win friends or get you a date, except maybe with a skunk. The malodor of skunk spray comes from a collection of thiols.

If you've ever kept a culture of fruit flies (Drosophila), you know the food they eat smells vile. It's like potatoes you left to rot in a cupboard for about a year, mixed in with old bananas, and possibly vomit (that last part could be yours, when you lose your lunch). Humans would rather starve than eat the stuff, but flies seem to enjoy it.

Microbiology labs smell odious. The odor of culture media is plenty bad when it's fresh, but when you autoclave those test tubes and petri dishes to kill the bugs, you get that an eau de gross perfume that can roil even the strongest stomachs. It's hard to say which type of medium smells worst, but meat and blood cultures rank high as being especially... well... rank.

While fly food and disinfected cultures stink, they won't hurt you. If you can smell formaldehyde, on the other hand, you know you're poisoning yourself. The chemical, often used as a preservative, has a distinct unpleasant odor. The nausea and headache are from the toxicity, not just the scent.

Paraformaldehyde, a related chemical also used as a fixative, possibly smells even worse.

Cadaverine is decarboxylated lysine that may be isolated from cadavers or pretty much any decaying dead animal. Think of it as purified essence of putrefaction. You're less likely to encounter it in a lab than the previous chemicals. If you can't get hold of any and want to know what you're missing, take a deep whiff of roadkill and count yourself lucky you don't have to deal with the smell in the enclosed space of a lab.

n-Butanol is a primary alcohol produced during carbohydrate fermentation. While it's a solvent in the lab, you'll also find it as an artificial flavoring in many foods and as a natural chemical in beer, wine, and other fermented products. While its toxicity is relatively low, n-butanol and other fusel alcohols may be the culprit behind severe hangovers. Some compare its scent to bananas or sweet vodka or window cleaner, though I think it smells like rancid alcoholic butter.

If you move down the periodic table from sulfur, you'll see selenium and tellurium. If you replace sulfur with either of those elements, you get a smell that not only won't win you friends, but will actively drive them away! If you won't work with the chemicals in the lab, you can get the barest glimpse of the smell from sniffing anti-dandruff shampoo that contains selenium. It's a musty, metallic smell that sinks into your skin and makes your breath reek. It's unbearable in a lab because any residue that escapes the fume hood sticks to you like olfactory super glue. You'll smell it for days (and so will people around you).

Beta-mercaptoethanol (2-mercaptoethanol) is used to lower the volatility of chemical solutions and as an antioxidant. It's a thiol that deserves its own special credit on the list. The odor is like a cross between rotten eggs and burnt rubber. The first whiff isn't terribly objectionable. The problem is the odor lingers for hours, plus it sticks to your hair and clothes, so you'll smell like you crawled out of a trash can even after you leave the lab. In high doses, it's deadly toxic. Breathing in a small amount won't kill you outright, though it will irritate your respiratory system and likely make you nauseous.

If you take benzene and switch out a N for a C-H, you'll have pyridine. This basic heterocyclic organic compound is a popular reagent and solvent, well-known for its distinctive rotten fish fragrance. It doesn't matter how much you dilute the chemical. It's like an old tuna sandwich you left in the lab for about a month. Like other organic compounds, it sticks to your olfactory receptors and taste buds, basically ruining any chance you have at enjoying your next several meals.