Lab safety: who’s on the hook?

I’m shamefully behind on my blog reading, and therefore didn’t see Richard’s excellent article on lab safety until the Guardian had already closed comments. I’ll therefore have to relate my story as its own post, instead of the comment I’d originally intended.


Richard’s article references a very sad story that’s rather famous among British scientists:

A fair few years ago now, a certain UK Research Council unit installed oxygen sensors in the room where they kept liquid nitrogen tanks. This is because liquid nitrogen rapidly boils at anything approaching room temperature, and naturally the newly gaseous nitrogen will rapidly displace other gasses—including oxygen. So if you’re working with or decanting liquid nitrogen and an oxygen alarm goes off, you get the hell out of Dodge before you asphyxiate. I’ve been there, done that. But in this particular case, the sensors kept going off, making it next to impossible for these particular people to do their work. So they muted the alarm.

Yes, that was a damn fool thing to do, and when there was a leak somebody asphyxiated and they found his body frozen to the floor. But why the sensor kept going off in that situation is something that H&S should have looked at, and, oh I don’t know, made sure the room was adequately ventilated, perhaps? Maybe even moved the tanks someplace else.

This happened while I was doing my PhD in Glasgow, quite close to the facility in question and in an institute funded by the same organisation. Our lab manager therefore took this development extremely seriously, and we were all asked to think of possible solutions to our own liquid nitrogen problem, which was as follows:

We all took it in turns to fill up our lab’s liquid nitrogen containers, and it was a task that everyone dreaded. The tanks were in a deserted corner of the basement, where you would often hear the skitterings of mice behind storage boxes, but never run into a fellow human being. The room was poorly lit, poorly ventilated, and rather musty (don’t worry, they’ve since knocked the old building down and replaced it with a shiny new purpose-built facility). It took ages to fill up the tanks from the single old hose (which would shriek like a banshee as the nitrogen flowed through it, adding to the creepiness of the situation), and your hands would freeze through the thickest of gloves… not to mention the chill that would seep into your feet and then the rest of your body from the fog of nitrogen vapour. Learning that this activity was potentially fatal as well as deeply unpleasant made us dread our turn on the schedule slightly even more.

The list of suggested remedies was long, technical, and potentially extremely expensive – sensors, lights, alarms, video monitors, new ventilation systems for the whole building, you name it.

Now, there’s an old story that when faced with the problem of normal pens not working in zero gravity, NASA spent years and millions of dollars developing a special pen for astronauts. Meanwhile, Soviet cosmonauts used pencils. This tale has sadly been debunked, but I’m proud to relate that my PhD supervisor is just as ingenious as any mythical Soviet engineer:

“Send people down there in pairs – one to fill the tanks, and the other to watch from the doorway, holding a boat hook to pull them out if they collapse”, he said. “I can provide the boat hook”.

Problem solved! We never needed to use the boat hook, thankfully, but it was nice to know it was there…

About Cath@VWXYNot?

"one of the sillier science bloggers [...] I thought I should give a warning to the more staid members of the community." - Bob O'Hara, December 2010
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10 Responses to Lab safety: who’s on the hook?

  1. DrMobs says:

    We have a super state-of-the-art PC2 facility with liquid nitrogen on tap in its own special room, with super-sucking ventilation, floor exhausts, low oxygen alarms and flashing lights. Lucky, because they’ve stuck so many SHOUTY warning stickers on the glass door that you can’t see in to look for bodies on the floor.

  2. chall says:

    boat hook FTW!

    We had a similar thing back home. Basement, scary things and a safety system “if I’m not back in 30 mins, go down and look” 😉

    That said, not liking nitrogen tanks that much…… still. But dislike the “non thinking alarm systems” even more. THey have to be practical otherwise they’re counterproductive.

    Did I tell you about the time I accidentally smacked the oxygen alarm in the walk in fridge? yeah… exactly as embarrassing as it seems. Never seen that many people running on the floor at 4 pm on a Friday.They refrered to it as a “non-planned test”. I refer to it as “always know how to reset the alarm when you accidentally trip it” …. (one of the post docs were happy to grab me and say “I save you” with hope of some romantic ending a la movie. no such luck. i’m such a bore.)

  3. Nina says:

    I can only relate a story I heard from someone else. Unlabeled clear fluid in lab. Is probably an acid, let’s pour into our acid waste bucket. Was not an acid. Boiling fumes, alarms, prof (yes, prof cleaning up students’ mess) half blind from exploding glass beaker with acid-non acid.
    Makes me shudder of those days in high school when we squirted each other with distilled H2O and prof got outrageously angry, as I can now see how worried he must have been …

  4. rpg says:

    Breathing apparatus for the standby of the pair might have been good as by the time the first has collapsed the O2 pp would be low enough to start inconveniencing them… but then you’d need training and expense etc.

    But yeah. Nitrogen. Scary stuff.

  5. Grant says:

    Isn’t the solution your lab supervisor offered is the same as is used in cold storage labs* – one person stays outside while their partner works inside, etc. – ?

    (* Rooms maintained at, say, -20˚C, used to conduct experiments on substrates that need to stay cold.)

  6. Laurence Cox says:

    I often wonder why people prefer to build in active safety systems rather than starting with passive safety. For example, if your big liquid nitrogen dewar is behind a louvred door to the outside environment, natural circulation will ensure that you won’t get a serious build-up of nitrogen gas. The odd splash of liquid nitrogen on your skin won’t cause permanent damage; as long as you have eye protection.

    Much more dangerous is liquid helium, where you really do need gloves to protect your skin when handling it.

    I did see Richard’s Guardian article in time to comment on it and would repeat my recommendation of reading Trevor Kletz’s books on chemical engineering safety (which actually have rather wider application, particularly “An Engineer’s View of Human Error”).

  7. I can report that the folks who deal with our tanks are required by Occupational Health and Safety to work in pairs. The things are alarmed to the teeth, too.

    On the other hand, I once visited a nearby hospital research institute (now renovated) where the prof I was visiting had her office near the end of a narrow, twisty hall, that was highly impeded by dozens of fridges, centrifuges, and, you guessed it, liquid nitrogen dewars. The main danger in this case, I think, would have been from fire – there was only one way out, through all the clutter.

  8. Steve Caplan says:

    On a tangential note:
    I love Richard’s description about “Getting out of Dodge.” Dodge St., by the way is the main East/West artery in the city of Omaha…

  9. DrMobs, that does seem like an oversight. Do you have any PIs who enjoy sailing? Perhaps one of them has a periscope…

    Chall, it’s nice to know they were there for you, even if one of them might have had less than perfectly altruistic motivations…

    Nina, speaking as someone with experience of dropping a large bottle of conc HCl while an undergrad and having it splash all over my lab coat, that sounds terrifying!

    (I peeled my gloves and lab coat off and threw them across the room in one fluid motion, while running out of the otherwise empty lab. When I came back in a while later the gloves and coat had massive holes in them, the elastic in the coat’s cuffs had fused into solid plastic, and there was a large scar on the floor that AFAIK is still there to this day. I didn’t get a drop on me, good little PPE rule follower that I am!)

    RPG, my PI was a sailor, not a diver 🙂

    Grant, probably, depending on the institution. I’ve worked in 4C rooms before, but have only ever used a -20C room for cooling down in after cycling up the hill to work in the summer. There was no risk as all the other cyclists were in there for company.

    Laurence, I’ve never worked with liquid helium, thankfully. Not sure I’d be confident enough to handle it.

    Richard, I’ve seen labs like that and it is kinda scary. Luckily, earthquake awareness is very high here in Vancouver, so exits are always kept clear, large pieces of equipment are bolted to the wall etc. It makes the environment much safer in case of fire and other disasters as well as earthquakes.

    Steve, I’m sure there are lots of local jokes about that!

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