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Today I was pipetting some cyclohexylamine into smaller bottles so that I don't have to use the liter flask every time I need a little bit of catalyst or plasticizer. I pipetted several 10-20 mL portions in the open air on a regular table.

Because I lack experience I'm extra precautious with what I do. From the MSDS's of cyclohexylamine I found that 10 mL will kill an adult male, which if you look at is isn't very much, less than a swig of water.

Of course I'm wearing a lab coat, safety goggles and chemical resistant gloves, but a few things concerned me (or at least made me wonder if it was the right/safe way to handle). According to the MSDS of ScienceLab the odor threshold is 26 ppm, while according to CAMEO, the PAC-3 for cyclohexylamine is 30 ppm, which Wikipedia defines as:

PAC-3 : Life-threatening health effects.

When I opened the bottle the amine fish odor was very strongly noticeable, I however found no irritating effect on my eyes or lungs, although according to the documents provided above I was inhaling a lethal concentration. I'm quite confused here. More easily put as a question: as long as I don't feel irritation of my lungs or eyes, am I safe? And if I do, is there enough time to clean up (i.e. the most essential things, like shutting off electricity and closing open jars of chemicals) and leave?

Finally I accidentally touched a drop of cyclohexylamine (from the pipette) when I was cleaning up, with no gloves on. Although cyclohexylamine is listed as highly corrosive, I did not feel any irritation at all. Then I rinsed my pipette 3x with distilled water and put the waste in a jerrycan, but I still haven't figured out if I can pour the diluted mixture of water and cyclohexylamine down the drain, without poisoning myself or the neighborhood. The MSDS's keep quiet about that.

Can someone clear some confusions up for me. I will be greatly appreciated!

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    $\begingroup$ It is possible to use nitrite in acidic solution to get rid of alkyl-amines. Idea is, that they form diasonium salt, that is quickly destroyed into alcohol and nitrogen. $\endgroup$ – permeakra Jul 22 '14 at 21:17
  • $\begingroup$ Yes, but I need the alkylamines for the reaction. Or are you saying this as a way of disposal? In that case, your comment is appreciated and I'll look into it. $\endgroup$ – Jori Jul 23 '14 at 14:24
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I once did some work with some small chain alkyl amines and they were bad news. They would actually burn you if some got on your skin. I always used a respirator and worked in a hood when using them.

as long as I don't feel irritation of my lungs or eyes, am I safe?

If this is a one time occurrence, given the small quantities, I'd say the odds are way in your favor, but they call it "odds" for a reason. My advice would be not to do it again without a respirator and hood where the exhaust is treated.

And if I do, is there enough time to clean up (i.e. the most essential things, like shutting off electricity and closing open jars of chemicals) and leave?

If you ask an industrial hygiene professional, I'm sure the answer would be "no". If it were me and I just began to notice some very mild sensation, I think I'd hold my breath and try to shut things down. I know it doesn't make sense, but that's what I'd do. If I noticed anything beyond the onset of very minor discomfort, I'd clear out fast and call the fire department.

Finally I accidentally touched a drop of cyclohexylamine (from the pipette) when I was cleaning up, with no gloves on.

I'd keep washing it every so often during the day and I'd put some burn cream on it in between the washings. I'd also take a good shower. No harm in overreacting.

still haven't figured out if I can pour the diluted mixture of water and cyclohexylamine down the drain

I'm almost positive that the answer is no. Besides you and the neighborhood, it might react with the pipes or what's stuck in the pipes and create longer term toxicity problems when you're in that room at some later date. Where I live, we have hazardous chemical drop-off centers (mainly for paint, oil and household chemicals, but used for everything chemical). I'd pay the relatively small amount they charge and drop it off there.

One final note, even when using the right protective gear, some people become "sensitized" to amines. This means that future exposure at even lower levels to a wide array of amines can be more dangerous. Also, I'd try to open up the exposed room to as much outside air as possible, use a room fan too if you have one.

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  • $\begingroup$ Wow, and I haven't even started heating it up for refluxing. I don't have a professional lab, I did install a fumehood, but it remains amateur work. Notice I'm talking about liter quantity (one liter to be precise and 20 mL in situ), not industrial quantities. When reading reports about reactions involving alkylamines I never say people explicitly warning about them. I always thought that methylamine and n-buthylamine for example are widely used chemicals, that require safety measures, but not something like a respirator and professional filtering fumehoods $\endgroup$ – Jori Jul 20 '14 at 21:05
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    $\begingroup$ How are people using these compounds at home?! :) Pretty sure no one I ever saw mentioning these compounds has such safety measures installed. $\endgroup$ – Jori Jul 20 '14 at 21:05
  • $\begingroup$ n-butylamine (nBa) is what I worked with, really bad stuff. They are widely used in industry, but so is cyanide. I talked with guys who worked with drums of nBa in industrial manufacturing applications, that's where I heard the sensitization stories. 1 liter sounds like a lot to me. $\endgroup$ – ron Jul 20 '14 at 21:11
  • $\begingroup$ Not in situ, 10-20 mL in situ. 1 liter in storage. Or do you mean that? I couldn't even get less, else I would just have ordered 100 mL or so. The chemical supplier I got it from seemed it not dangerous enough to not supply it to individuals. I mean, I knew it was bad stuff, but always considered it something similarly dangerous to sulfuric acid or concentrated lye (NaOH), which can be relatively safely handled by amateurs. $\endgroup$ – Jori Jul 20 '14 at 21:15
  • $\begingroup$ Yep, I understood you, I just wouldn't want a liter around for someone to knock off the shelf or whatever. The industrial guys took precautions with the small alkyl amines that they didn't take with acids and bases - like respirators and only using it in hoods marked for amine use that led to rooftop scrubbing before release to the atmosphere. $\endgroup$ – ron Jul 20 '14 at 21:27
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There are some general points that need to be made about this question, and some will not directly answer your question. They may, hopefully be useful for future generations of home-chemists seeking answers on this site.

Firstly, all of these very practical questions should have been asked well before you carried out this process. Hindsight is a wonderful gift. Prior to any chemical handling process, all industrial and research chemists will carry out an extensive Hazard Identification and Risk Assessment. Prior to taking possession of this chemical you should be aware of how to store, handle and dispose of your chemicals. Disposal management includes spill control and safe disposal of unwanted waste materials.

Secondly, spilling some material on yourself during cleanup indicates that you were not sufficiently protected. Gloves, glasses, labcoats and other protective equipment need to be used during cleanup as well. Accidents can happen at any stage, and you need to be prepared for this.

Thirdly, if you are using a hazardous chemical in an environment where you can so readily smell it suggests to me that you have inadequate ventilation in your work area. You should address this immediately.

Finally, the first Risk Control measure the home chemist (any chemist!) needs to consider is subsitution. Is this really the only suitable reagent for you to use, or can you substitute it for another, less harmful, chemical?

Cyclohexylamine is a nasty chemical. It has a GHS signal word DANGER, which should immediately make any handler seek further information prior to using it. It is classed as

  • Category 3 flammable liquid,
  • Category 2 Oral Acute Toxicity,
  • Cat 3 Dermal Acute Toxicity,
  • Cat 1 Skin corrosion,
  • Cat 1 Serious Eye Damage and
  • Cat 2 Reproductive Toxicity.

Yes, Cyclohexylamine is a nasty chemical. Now, on to your questions.......

"as long as I don't feel irritation of my lungs or eyes, am I safe?"

No, no, no, good god, no. You will be subject to the dangerous effects of any chemical as long as you are exposed to them. Many effects will not be instantaneous; many can take hours or days (or even weeks) to manifest symptoms. I recall a case in the mid-90's, as an example, where a postgrad student died after cleaning up a spill of acrylonitrile in a lab. Symptoms of distress only became apparent several hours after the incident, and the person was hospitalized and died within 24 hours. Acrylonitrile essentially dissolves the tissues of the lungs. Not a nice way to die. Your lungs and eyes are the most sensitive areas of your body, and are likely to show irritation first. Consider, however, that your skin (especially your face) may have a much greater area of exposure, and this may be a pathway for contamination.

The PAC guidelines you ask about relate to extended periods of exposure. It does not mean that if you inhale 30ppm of a particular chemical you will experience life-threatening health effects immediately. Perhaps a more relevant and practical exposure guide is the Acute Exposure Guideline Levels (listed in your first reference), which shows that extended exposure at 30ppm for an hour could lead to life-threatening health effects or death. Or 10 minutes at 38ppm. The take home message from this is that if you can smell it, you are working in a dangerous environment.

"I accidentally touched a drop of cyclohexylamine (from the pipette) when I was cleaning up, with no gloves on".

Clearly, your previous statement "Of course I'm wearing a lab coat, safety goggles and chemical resistant gloves" was not quite correct. Personal safety equipment should be the first thing to go on, and the last thing to come off. I hope you treated the exposed area according to the MSDS first aid advice. Like other adverse chemical affects, corrosive properties do not need to be instantaneous. They can take a long time to manifest symptoms; HF, for instance, does not produce inflammation or burns until many hours after exposure.

"I still haven't figured out if I can pour the diluted mixture of water and cyclohexylamine down the drain, without poisoning myself or the neighborhood."

Many SDS do not explicitly describe safe disposal considerations, and you should probably seek a more comprehensive source. Chemical suppliers should now be moving toward the GHS system for chemical management, and the SDS from these companies should include (albeit brief and generic) disposal considerations. However, this is a chemical which is toxic to the environment and should be disposed of correctly. Most local Council or Municipal Waste Management Facilities will have chemical collection days, or specific chemical drop-off centres to receive these types of items. Speak to your local government authority, and seek advice from them. Occasionally, for some chemicals, you can return any unused portions to the place of sale. Normally, these types of chemicals are burnt in a chemical incinerator with afterburner and scrubber. You should collect waste mixtures in an appropriate container and store safely until ready for disposal. For small volumes of waste, you may consider using the spill control guidelines, which may offer a more practical approach to providing a safer chemical to store and dispose of.

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  • $\begingroup$ Now I must note that I only smelled the fish odor after opening the flask. It went away after that. The pipetting was done outside. Yes while cleaning up I should still wear everything, stupid mistake, but I still don't have any symptoms. Cleaning up is in issue too indeed, but the MSDS's mostly are quiet about that one too for non-industrial spill. Thanks for your answer. $\endgroup$ – Jori Jul 21 '14 at 10:21

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