I believe I found it was 3% peroxide and up to 7% glycerin. Peroxide is very unstable and breaks down in heat, light, or if shaken hard so I have no concerns about it. None of the byproducts will harm food and will assist in burning the alcohol if anything. That leaves about 10% as water and the rest ethanol.
I haven’t looked in great detail about separating the glycerin but feel it probably wouldn’t be worth it. All my searches revealed extraction processes for medical cannabis as a mixture of ethanol and glycerin is used. I am not a chemist but apparently glycerin is in the same family as alcohol and sugars so odds are it would be energy intensive, costly, and time consuming to separate.
I really feel that most of the glycerin just builds up at the bottom of the burner. This is something you can just wipe out with a paper towel. The sites mention that the toxic byproducts have a nasty smell like burning fat or cooking oil and I didn’t smell any of this. I think the alcohol vapor just boils off and leaves the reservoir of this mix at the bottom relatively cool. Glycerin isn’t easy to burn so just gets left behind as a syrup. I am probably more concerned about this than I should be but won’t cook directly over the flame, only in pots or pans.
I will also not discount giving this stuff away to friends, family, or schools if the nature of COVID-19 changes with a future variant. I certainly don’t plan to just take it to a hazmat disposal place.