Update March 7th: I’ve upgraded the threat level of DCE. Disposal instructions have been removed, as they were too site/quantity specific. YMMV.
Here’s a little something I made for our lab, as a means of teaching incoming students appropriate solvent practices. Solvents are arranged roughly by the degree of health risk from mild (top) to severe (bottom right). Only new control measures are mentioned at each level; all preceding warnings apply.
Colour version. Click for larger, print ready image.
The same chart, in black and white. Click for larger version.
As much as possible I’ve tried to assign hazards based on available health data. If I’m missing your favourite solvent or you disagree with a label let me know in the comments.
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Hmmm. I might move the hexanes down, based on what we know about their neurotoxicity (after chronic large-scale exposure, that is.)
I don’t understand why DMSO is listed as hazardous/toxic? Is it because it’s easily absorbed through the skin, and in that way toxic because of whatever is dissolved in it? Or is there something I’m missing?
I agree with Wim, though you can never be too careful.
In addition to this : anyone in my lab dumping methanol, (iso-)propanol or (especially !) acetonitril in the sink is going to get his/her behind kicked. Also, I would certainly not classify n-hexane as a ‘low hazard solvent’, and the same goes for the ethers (because of peroxides). They are nicely stored in the dark in a chemical safety cabinet in tightly closed bottles.
Furthermore I would put 1,2-DCE, DMF and NMP in the hazardous/toxic box.
Love this blog, but I don’t think I would put this up in my lab…
Chemjobber, I was debating the hexanes location. They’re certainly not something I’d want to breath on a regular basis, but didn’t seem significantly more hazardous than diethyl ether. The green box basically translates to “a whiff every now and then isn’t too harmful, but don’t start huffing it”.
Wim, DMSO is got its ranking for it’s ability to carry toxic chemicals through gloves/skin. In and of itself it is relatively safe.
Hans, chemicals are ranked based on their acute or chronic effects on the human body (as best I could determine). Methanol and isopropanol are relatively benign, so long as large quantities are not ingested, and are rapidly metabolized by bacteria (hence disposal down the sink). Acetonitrile has roughly equivalent toxicity, and is commonly mixed with water for HPLC experiments. I don’t have extensive experience with it, so if you have any information on common disposal practices there I’d be happy to amend the chart.
This chart is primarily concerned with direct exposure, so the ability for ethers to form peroxides was not considered. DMF and NMP have very low vapour pressures, which limits the risk of inhalation and keeps them out of the toxic box. DCE may be misassigned; I assumed it was of roughly equivalent toxicity to DCM.
Where do you work that you can sewer acetone, acetonitrile, the alcohols…? While that may be acceptable there, it is not universal advice. EPA and State EPA Hazardous Waste Permits will ultimately decide that for you.
Also, there is the wonderful irony that if you get water on your skin, you should wash the area with water for 10 minutes.
In short, it is a nice chart that you may want to use as “guidelines” internally, but that should be the end of it.
Acetonitrile isn’t very toxic as far as I know, but I don’t like to have lots of it out of the hood becasue it has a not particularly unpleasant, but strong and slightly annoying odor kind of like popcorn and wet cardboard.