Sciencemadness Discussion Board

Handling of Aniline

Rando1234 - 17-1-2022 at 13:16

Hi All,

I am considering an experiment that involves handling freebase aniline. I'm concerned about handling it because of its volatility and carcinogenic and toxic properties. I've only ever handled its hydrochloride salt (produced by hydrolysis of acetanilide) to use in diazonations. Works pretty well, by the way.

The process I'm doing involves heating it at 110C for 2 hours with paraformaldehyde and substituted phenols to make a derivative of benzoxazine. I'm doing it on a 10 gram scale. Are there any other concerns here besides the obvious concern of formaldehyde vapors?

I have access to a respirator, goggles, gloves, lab coat, and a well-ventilated workspace. Do you think it's safe for me to handle freebase aniline under these circumstances?

Thanks,
Jacob

B(a)P - 17-1-2022 at 14:22

The most significant exposure route for aniline is via dermal adsorption, so make sure you have a set up that will ensure any accidents/failures don't mean that you end up covered in the stuff.
For aniline you might like to double glove and have suitable protection to prevent any splashes getting on your skin. Note that is a commercial setting a full body suit is often worn if there is any chance of spills or splashes when dealing with aniline.
For respiratory protection you will need ABEK cartridges. Given the dermal contact risk a full face respirator is probably the most appropriate. You then need to decide for yourself if you have enough ventilation such that you do not exceed the vapour concentration that your respirator is rated to. A full face respirator is good for approximately 50 times the exposure limit (assuming it is well fitted and you are clean shaven), so for aniline you wouldn't want much more than 5000 ppm in your breathing space.
Hope this helps and best of luck with the synthesis!

Rando1234 - 17-1-2022 at 14:33

B(a)P: Thanks. I'm only working with about 2-5ml aniline at one time, and I do believe that my ventilation and the reflux condenser I'm putting over it should go a ways to protect me from the fumes. I do have a tight-fitting full-face respirator and I am clean-shaven which I think will do help a bit. Unfortunately the cartridges are only P100...do you think it still will be safe to work with?

Edit: I just ordered ABEK cartridges for my respirator.

[Edited on 17-1-2022 by JacobM]

B(a)P - 17-1-2022 at 14:47

Unfortunately a P100 cartridge will not provide any respiratory protection from organic vapours. They are designed to remove particulates.
The good thing about aniline is you can smell it before it becomes dangerous to your health from an inhalation perspective. If you can't get access to ABEK cartridges you could just use your mask for dermal protection (preventing splashes getting on your face), then leave the area if you can smell aniline. Obviously this isn't ideal, but it might be suitable for the scale you are talking about.
I can't tell you if it is safe or not, that is for you to decide, but hopefully the information I have provided can help inform how you proceed.

B(a)P - 17-1-2022 at 14:49

Quote: Originally posted by JacobM  


Edit: I just ordered ABEK cartridges for my respirator.

[Edited on 17-1-2022 by JacobM]


Excellent, they are very useful. Make sure when you are done with them that you remove them from your mask and store them in an air tight container or bag. This way they will last for quite some time.

Rando1234 - 17-1-2022 at 14:49

I'm going to wait for the ABEK cartridges I ordered to arrive before I do it. That should probably help me work with it safely. That's probably the safest choice.

Rando1234 - 17-1-2022 at 14:50

Thanks, I'll make sure that I do that.

mackolol - 18-1-2022 at 02:56

You might as well consider wearing a visor. That will protect the skin from anilline potentially splashing on your face.

[Edited on 18-1-2022 by mackolol]

Rando1234 - 18-1-2022 at 05:44

Ah, I think I have one I can wear somewhere. If I can find it I'll use it.

MaeBorowski - 20-1-2022 at 15:11

I worked twice with a significant amount of pure aniline (about 60 g). I think several drops on your skin can't damage your health more than 6 h in full-body chemical protection suit or something like. Aniline is average toxic, but it doesn't accumulate in your body so you can work without a gas mask and even gloves if you are dexterous enough. The final choise is yours

zed - 29-1-2022 at 23:46

Build some sort of a fume hood. Masks and cartridges, aren't supposed to be a substitute for a good hood.

They are more like an adjunct to be used in addition to a hood.

GANS - 2-2-2022 at 07:06

Also mind your glove material, it might be worth investing in a pack of Gloves made from Fluor or Butylrubber. The Nitril ones arent recommended cause of smaller permeation times, even tho thats on a industrial scale. (smaller permeation times in this case mean =< 30min for the nitril work gloves we use)

Crazy_Chemist - 12-3-2022 at 01:52

I heard once, about a guy who sat in chair there someone had poured anilin on it, and it absorbed through the clothes and he died.. :(