And

https://f-droid.org/packages/ch.nilsgrob.android.bluemoon

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Co2 can be effective as a mild anesthetic at certain percentage, causing relaxation and drowsiness. So can be used to euthanize animals humanely and without toxicity. If the levels rise above that threshold, you experience a burning throat and a feeling of suffocation. Which is not humane. I imagine it’s what the videos show.

That’s the best part, companies do that for you