Protocol Online logo
Top : Forum Archives: : Molecular Biology

chronic exposure to Trizol (phenol)? - (Dec/14/2006 )

Greetings fellow molecular biologists,
First, I apologize if this post is in the wrong place, but I was hoping to target those of you who use Trizol or similar reagent for isolation of nucleic acids or proteins. Moderators, please feel free to move it if necessary.

I am concerned about my occupational exposure to phenol and/or chloroform. I have been spending the last several months isolating RNA samples with Trizol, and I do this on a daily basis. I usually perform the addition of chloroform under a fume hood, but our lab is not conveniently set up for me to continue with the rest of the isolation process under a fume hood (i.e., I would have to walk through 3 rooms and a hallway to get between the fume hood and the refrigerated centrifuge). When I started, the person training me did not use a fume hood at all. In any case, should I be concerned? What do you all do?

The reason I ask is because for the past several months I have suffered from mild eye irritation, and it has gotten to the point where my eyes are always red and dry by the end of the day. I can no longer wear my contact lenses either (although it probably isn't a good idea in the lab anyway). And tonight, it dawned on me that I may have brought this on myself!

I have researched a little about phenol toxicity, and I am aware that it can cause eye problems. But what I don't know is whether the levels in Trizol are high enough for concern, or if I am barking up the wrong tree to make my eyes healthy again.

Thanks for any input you have!


well considering the fact ou're in contact with plhenol and trizol there are few points i observe.
First, i work on cold room for all the extraction works good (agilent test) and reduces fumes.
Phenol and trizol are not comatible with wearing contact lenses. So days i work with trizol is without lenses. But fortunately i can move relative well without them.

Second point is that you need to change your latex glove at every drop going on it. Latex monomers are formig, and cross the skin barrier.

finally you may ask for global blodd analysis in a work-related control.


Trizol is composed of 38% phenol. It is a concern, especially when in contact with bare skin as said phenol is acidified, making it easier to damage the skin and get into your body.

It is a shame to say, but I don't work using a fume hood (though I do use gloves.. changing them immediately after using phenol.)

I close all my containers/eppendorfs immediately after adding my phenol. So fume aren't really a problem. And likely help as I work with my stuff a foot away from my face. I don't work with my head hovering over my reagents as some people are prone to do.

I don't wear contacts... which probably could trap any vapours under the lens and thus prolong contact with the eye.


Thanks for your replies, I learned a lot. I did not realize that Trizol had that much phenol in it, and I did not know it is not compatible with contact lenses! I asked my eye doctor this morning, and it is quite likely my contact lenses were absorbing the contaminants and constantly exposing my eyes to them every time I put them in. Wow, now I know to be a lot more careful. When I started, I only worked with small batches of samples at a time so I decided that keeping the caps closed, etc, would keep exposure at a minimum. But it did not really occur to me to make any changes when I switched to working with large batches. Also, I was keeping the waste beaker out, open, on the benchtop. I really should have known better.

In any case, I have moved my Trizol operation entirely to the fume hood. The inconvenient walk to the centrifuge is worth it. In addition, I know to wear glasses on days that I isolate RNA and also I am switching to daily wear contact lenses. In my field, it is likely I'll be exposed to many bad things, so my doctor wants me in lenses that I throw away at the end of each day.

If anyone else has experiences, I would still like to hear them, even though I hope all these changes solve my problems.

Thanks again!!


Chronic exposure to phenol is a problem, causes neurological effects as well as those mentioned in other posts. However, a small exposure will not have much effect; there is 0.5% phenol in Blistex lip gloss or whatever it is, and it can be used continuously.

Phenol is particularly bad at "creeping", I find that it can get out of tubes even if they are closed tightly, so wear double gloves or even better Nitrile gloves (the purple ones) when handling phenol solutions. I always work in a solvent hood and on ice too.

I wear glasses all the time and deliberately got glass lenses rather than plastic so that phenol extractions wouldn't affect them. Admittedly my lenses are quite weak, so the glasses don't weigh too much, but they are still pretty heavy for todays standards.