[kube-system]

So that you don't risk harm to other people and property in the process?

[gruez]

a tank of helium + mask/bag satisfies that criteria.

[kube-system]

A person in these dire circumstances is likely also someone lacking the resources and ability to accomplish any of these "DIY" schemes. People in care homes are there because they have trouble taking care of their basic needs.

[sli]

Consumer helium is sold with a good amount of oxygen in it now for exactly that reason.

[nradov]

I'm pretty sure that's a myth, at least in most areas. Helium tanks usually contain >99% pure helium. I've never seen one with a significant amount of oxygen.