Top 10: Worst Lab Smells

Time for a bit of fun. Here are my top 10 worst lab smells, in reverse order. Please share your worst smells in the discussion!

10. I’ll start off gently with Latex Gloves. Not truly a offensive smell, just a little off-putting

9. Ever stewed a turnip for far too long? No. If you did, it would smell like autoclaved cell culture waste. Yuck.

8. Looks deceptively nice, pink and sherbert-like, but powered Virkon has a very strange smell. Especially if you are unfortunate enough to get a little up your nose. Paradoxically, I think the solution smells quite nice.

7. Moving up the food chain to something that might start to put you off your lunch: Fly food. What do they put in that stuff? Year-old bananas?

6. One thing that did put me off my lunch when I was an undergraduate was formaldehyde. I had to walk past the anatomy department every day to get to the sandwich shop and never felt much like eating after that.

5. Into the top five with one of the big hitters: Ammonia. Nauseating in low concentration and if you are lazy enough to adjust pH with conc. Ammonia outside the hood it can almost knock you off your feet.

4. Paraformaldehyde is at number 4 for for me for a very specific reason. I once spent an afternoon doing fixations with paraformalde with, stupidly, my head in the hood (see no. 10 in 10 Stupid Lab Safety Mistakes). I paid for it with a weekend in which everything tasted like paraformaldehyde, and since then it has always been one of my worst smells.

3. This top 10 could be peppered with organic solvents, but I decided to just put in my worst: N-Butanol. Nasty, sickly stuff.

2. The only reason that Cadaverine is not number one is that it is not used in everyday protocols (thank goodness), but it is possibly THE most foul-smelling thing I have ever come across. Cadaverine is a compound produced during the decomposition of animal tissue (it is decarboxylated lysine), and is partially responsible for the horrible smell of rotting flesh. It smells like decomposition in a bottle. Nice.

1. I think we could all guess that Beta-mercaptoethanol would be near the top of this list. It is top because it is such a gut-wrenching smell, but also because it is one that seems to be released into the lab at least once a year (when the new PhD students come in). I myself participated spectacularly in that ritual in the first year of my PhD by dropping and smashing a bottle of BME, triggering a full-scale evacuation of the lab. Ah, the memories.

Now I KNOW you want to share your worst lab smells, go on… hit us with your worst!


  1. sina on March 20, 2019 at 10:06 pm

    who can tell me why temed smells like a child pee on himself ?

  2. PS on March 16, 2018 at 7:12 pm

    I work with dithiothreitol (DTT) all the time, and I can say it smells almost as bad as BME. Though for me, the smell always reminds me of a college roommate who was (a) obsessed with making his own cannabis edibles and (b) was very flatulent. DTT smells exactly like my old roommate’s weed-farts.

    • PS on March 16, 2018 at 7:14 pm

      Also, a corowker of mine once had a job extracting DNA from human urine and fecal samples. That couldn’t have been too nice. Especially the one time that he accidentally had the vacuum pump running in reverse and fired a 3 mL urine sample at the ceiling.

  3. EH&S on December 5, 2017 at 5:06 am

    TEMED smells like a little kid who pissed their pants and just kept wearing the same underwear and pants for 2 or 3 more days (it literally smells like that). 2-Mercaptoethanol is even worse! It smells exactly like the worst rotten egg fart imaginable. It is truly horrible. The 3rd worst thing I’ve ever smelled was back in 2005 or 2006. I was disposing 4 Liters of Tritiated horse urine that had a label on it which dated back to the late 1950’s. It was bad, because I had to pipette a sample before running the sample through the liquid scintillation counter in order to calculate the amount of H-3 that I disposed of. And when i finally poured the entire 4 Liters into the sink, the very small room I was in was a deathtrap of odor for 30 or more minutes. I couldn’t open the doors to ventilate it because it was a hallway. So I just left and later on heard complaints from 2 others in my dept who walked into the putrid aroma.

  4. Alison Ward on November 29, 2017 at 7:38 pm

    I’ve got to say that the worst one that I have worked (even worse than BME and TEMED) is trimethylamine. It is what gives rotting fish its distinctive smell. Weighing out powdered TMA is not for the faint of heart!
    The runner up is rumen fluid (i.e. fluid from a cow’s stomach). It is probably not something that you would encounter outside of the field of animal science, but it is a powerful stench (thing vomit combined with rotting cheese and other foul things).

  5. Lab 911 on December 23, 2015 at 11:29 pm

    The stink-bomb that some idiot made with decaying chewed up ham from their sandwich, that, or the BME that some idiot filled a water balloon with and dropped in the men’s bathroom.

  6. DougB on April 26, 2012 at 8:15 pm

    HI Nick,

    Yes, this subject was too good to pass up. A once previous job included testing sewer samples every day. Those are the samples that include all waste even human. Hydrogen sulfide was another one. I know it is poisonous. However, I couldn’t avoid the smell altogether.

    Doug B

    • Doug on April 27, 2012 at 7:09 pm

      I work with BME and trizol regularly but my most hated lab smell was a colleague’s cologne. Cheap rancid stuff applied with a paintbrush.

  7. grahampositive on October 26, 2011 at 9:55 pm


  8. gray1720 on September 20, 2011 at 12:43 pm

    TEMED and BME are the worst I’ve encountered. However, I have to nominate Salmonella arizona cultures as a runner up to those two. It obviously does something different to other Salmonellas, which just smell a bit, but if you can imagine the after-effects of washing down curried brussels sprouts with ten pints of real ale… that’s what it’s like. Possibly the cabbagiest smell in the known universe?

    I did work with someone who actually liked the smell of TEMED. Mind you, he was from Iceland, so probably associated fishy amine smells with home.

  9. poorpostdoc on September 6, 2011 at 3:47 am

    Hot acetic acid from Fairbanks’ staining for polyacrylamide gels, but the decrease in time is worth is (30 minutes instead of all day).

    • Richard Adams on September 7, 2011 at 2:01 am

      Decaying Xenopus egg extract is my worst lab smell – not only nauseating but persistent as well

  10. Fiona Mumoki on July 29, 2011 at 9:11 am

    TRIzol and Beta-mercaptoethanol are the worst for me, yet, I can’t seem to get away from them!
    Love your list BTW!

  11. Duc Dung Le on July 15, 2011 at 2:45 pm

    I’m doing Immunehistochemistry, after staining slices must be laquered edge with nail polish and stored in wall cupboad, thats hanged high about my nose. at each time, when I open wall cupboad to take my slices… oh my god, all of nail polish stink smell creep direct into my nose…..

  12. yevgeniy on July 12, 2011 at 1:54 am

    Good list. Any bacterial culture will pretty much smell like sewage. Culturing yeast, on the other hand, might smell like a visit to a pub if you close your eyes and try to imagine a dive bar. But in all honesty, anything that has sulfur in an organic chem lab will have your non-science friends wondering what unnatural foul smell you kindly decided to share with them after work today.

  13. Cristy Gelling on July 11, 2011 at 8:34 pm

    Our aspirator trap sometimes ends up festering with a random cocktail of discarded supernatants – and some mysterious chemistry makes the smell toatlly unbearable. My best guess is that it’s a combination of spent LB, PMSF, DTT, alcohols and extremely hardy bacteria.

  14. Cippin on July 11, 2011 at 4:58 pm

    DTT. My God that stuff is horrible! But for me concentrated ammonia will always be the worst – I can get nose bleeds from the stuff!

  15. Mike D. Jones on July 11, 2011 at 3:45 am

    I don’t find BME so bad. I think it’s a strong smell, but it smells “natural,” like rotting food or skunk. I most dislike chemical smells that smell unnatural (synthetic) , like TEMED, isoamylalcohol, and formaldehyde.
    As a note, aren’t paraformaldehyde and formaldehyde the same thing when in aqueous form?

  16. Ben Mudrak on July 9, 2011 at 3:47 am

    Ever smelled a 40-liter fermenter full of diarrheagenic E. coli? The bacteria can reach insanely high densities and make insanely bad smells.

  17. chadn737 on July 9, 2011 at 1:53 am

    2-Chlorophenol, doesn’t matter if you do all your work in a hood, the smell will spread.

  18. CSManuel on July 8, 2011 at 4:14 pm

    I work in a lab that often hunts for certain pathogens in cow poop. When we have fecal enrichments incubating, our entire floor absolutely reeks! Also, since we are in the Animal Science building, sometimes we get weird projects on our floor, like the time another lab put diapers on cows, collected total excrement for a full day, and then analyzed it for dry matter by putting it in a convection oven. Stunk up the entire building

  19. TimS3429 on July 8, 2011 at 2:29 pm

    I can’t smell BME. I can kind of get a garlic-like whiff of it when I press my nose into the bottle…..must be missing a receptor or something. Anyway, I guess it makes me lucky!
    TEMED smells really rank.
    And Acinetobacter sp. have recently made our lab smell worse than week old baby diapers left in the sun.

    • user-00001 on August 12, 2013 at 10:51 pm

      Hmm… I actually don’t think Acinetobacter smells that bad. In fact, it smells kind of like grapes. Could be just me though.

  20. Sacha on July 8, 2011 at 12:59 pm

    I think you never worked (and hope for you, you will not) with meat-based media for bacterial growth…
    Cooked meat medium smells awful after a few days-weeks of culture, and even worse once you autoclave it to kill bugs. My lab mates hate me…

    Another lunch-outputting experience is to pour petri dishes from 3L of media with added blood.

  21. maggieeiggam on July 8, 2011 at 11:03 am

    temed + LB..!

  22. micronaut on July 8, 2011 at 11:01 am

    beta-mercaptoethanol is the worst, if not for phenol which is killing you if you can smell it.

    I used to work in a hospital diagnostic bacteriology lab. You can’t beat a good pancreatic drain fluid.

    It was nice to find a Streptococcus milleri though – smells like caramel 🙂

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