The oxidation of chloroform is dangerous because it results in phosgene formation under exposure to UV light. Along with the minimization of UV exposure, this reaction is usually prevented with 1% ethanol by mass (or less commonly, amylene). I find this information everywhere online, but never find a clear explanation of why this is the case.

Since isopropanol is so similar to ethanol, how come people don't use it to stabilize chloroform? Does it not work? Is it because its less volatile than ethanol? Does the prevention of phosgene primarily work in the gas phase?

Also, what would happen if the concentration of ethanol was increased from 1% by mass? What would be the problem with this aside from purity concerns? Would the same concerns apply to isopropanol if it does stabilize chloroform?

More Yazen Alnefeesi's questions See All
Similar questions and discussions