Laboratory Safety

Yersinia yersinia at CYBERNEX.NET
Sat Oct 11 13:52:55 EST 1997

Hello all,

I was going to continue on the mouth-pipetting topic (Vodka Kills 
Germs?!) but notice that we who are interested in this thread seem to be 
straying a bit...so I took the liberty of changing the thread name...I 
hope no one minds.

Joseph Michael Bay writes,

<Odd.  I had this one advisor who actually *made fun of us* for *not* 
mouth pipetting.  He scoffed at safety!  He laughed at precautions!  He 
would stick his hand into (unpolymerized) acrylamide and say "Now my hand 
numb!"  What a hoot.>  and <(This sounds like a really bad idea, if 
you're using mouth pipetting.> 

I would never make fun of people who chose not to mouth pipette, nor 
would I stick my hands into substances like that,  HOWEVER, if I was a 
biology or chemistry lab instructor WITH THE FREEDOM TO CHOOSE HOW TO 
TEACH MY LABS (It's SCHOOL policy, not necessarily the policies of my 
individual professors, to prohibit mouth pipetting, and force us to wear 
gloves and safety goggles/glasses in chemistry labs), I would simply 
state the possibility of swallowing dangerous organisms while mouth 
pipetting and point out that some of the chemicals we are working with 
are hazardous/why this is so/what can happen if they swallow/get it on 
their skin, etc. Then I'd proceed to strongly RECOMMEND the use of 
pipetting aids in lieu of mouth pipetting, and in addition to pipetting 
aids, make gloves and goggles available to those who felt safer wearing 
them - but I would not try to FORCE anyone to use the pipetting aids or 
wear the gloves/goggles. In other words, I would make my students aware 
of any existing dangers of the experiments, and leave them to be 
responsible (or not) for their their own safety. The whole point I'd like 
to make here is that of personal responsibility and the freedom to make 
knowledgeable choices - and to take responsibility for the results of 
one's actions; in addition to lab-by-lab "Today's experiment involves..." 
descriptions of potential hazards, at the beginning of the semester, I'd  
give a "general safety speech" with handouts and have everyone sign a 
form saying that they received, read and understood this information, and 
if they chose to ignore safety procedures, they could not sue for medical 
expenses related to injuries they incurred as a result of ignoring the 
safety recommendations. Which I'm sure is one reason why my school has 
the "force everyone to use PPE" policy) But of course if I taught in a 
school whose policy was forcing students to adhere without exception to 
occasionally unnecessary safety precautions, I'd have to abide by that 
(or find another career).

As for my individual safety preferences (which is what I'd teach if I was 
a micro or chem lab instructor), in virtually all instances I DO NOT 
mouth pipette - by personal choice as much as to follow the rules in labs 
that prohibit it. The only times I do find mouth pipetting preferable is 
for cylinder plate antibiotic assays, to mouth pipette the base layers 
only (sucking up and dispensing 21 mL of media in a giant pipette with a 
bulb hurts my hand, and even the automated pumps take too long; it's 
easier and faster to mouth pipette in this case)  - and occasionally when 
I can't find my bulb or pump and I only want to fill a few tubes with 
uninoculated media for growth promotion samples or saline/buffer/peptone 
water for diluent - but that's it. I hate gloves and wear them 
VOLUNTARILY not for safety reasons, but for aseptic technique reasons, 
like when working under a sterile hood to make stock freeze cultures or 
do other similar tasks (but I had to wear them in school chem labs, which 
didn't require aseptic technique; I find gloves cumbersome as well as 
largely unnecessary -  but the lab instructor insisted we all wear them, 
school rules).  I gave up wearing contact lenses when I began working in 
labs, just in case I do splash or spill something nasty in my eyes, which 
contacts would complicate. I don't mind safety shields on my glasses, but 
I hate goggles since they fog up my glasses (oh yes, working half blind 
with dangerous chemicals is really to ensure my own safety and that of 
others, huh?) - nonetheless I've had lab profs who insisted that 
everyone, no exceptions, must wear safety goggles...I think the shields 
are more than enough for what I've done at school (microbiology, 
immunology, and now virology this semester, and chemistry) and work 
(micro labs only)  and what I plan to do in the future (more 

Does anyone else here have any thoughts about what constitutes good 
safety practice in microbiology labs? Lab instructors (I know there are 
some in this group), what kind of safety practices do you teach your 
students? Do you have to teach and insist on procedures that you as an 
individual scientist consider unnecessary, because your school policy 
requires it? Were the same safety procedures being taught when you were 
college or graduate students as you are teaching now?


..microcosmic....  :-)

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