askchapo

If you're in the US, your local pharmacy likely hosts a drug take-back box. You can put it in there, and congratulations: Safe disposal is now the responsibility of the DEA. Yes, Nicotine is considered a drug for this purpose, so this is the correct place to dispose of the liquid. Remove any personally identifying information, because nobody wants the liability.

As far as the flavorants go, those aren't a drug. If you're concerned about safe disposal and can't/don't want to research safe disposal of them, you can drop those off at your municipality's local Household Hazardous Waste Day (or Zero Waste Day) whenever that occurs for you.

Between these two options, you can get rid of basically anything you can't figure out how to safely dispose of for free.

Down the drain. The sewerage system will handle dilution very quickly and it's better than a lot of cleaners and other chemicals that go into there.

Unless you live somewhere with a septic tank. Or a greywater system.

Oh wow, few years ago I would have gladly taken that off your hands. Maybe try vaping communities? There are quite a few on reddit if you're willing to venture out there.

mine just lives in amber jars in my freezer for eternity

A friend of mine was in a similar situation with a dangerous chemical that he used for some hobby projects (an acid for glass etching)?

It wouldn't be accepted anywhere so he ended up calculating how diluted it needed to be and pouring it mixed with a lot of water down the sink.

For 5 litres of nicotine to be safe you'd need a lot of water though if you'd want to make this remotely ok for the environment...

What about mixing it with cat litter and then disposing it?

Have you looked into hazardous waste disposal in your area?

I imagine there are ppl like me around you who would use it.

into kitty litter in a ziploc and then into the trash? that's how you get rid of like morphine and script meds.

:illegal-to-say:

https://www.hazardouswasteexperts.com/locations/massachusetts/boston/

https://www.hazardouswasteexperts.com/waste-type/e-cigarette-waste-disposal/

https://cleanmanagement.com/service/e-liquid-waste/

Why don't you start by leaving the bottles out in the sun? UV light accelerates decomposition. I've also read that heat and elemental selenium will destroy nicotine.

You could also add an acid to precipitate into nicotine salt, which might be easier to deal with. Pick an acid such that the resulting salt is insoluble in whatever the carrier liquid is (water? glycerol?). Then you have solid waste.