I think it's a little more complicated than even that, but the cartridge disposal instructions usually come with all kinds of warnings about the stuff, so pick up any spills carefully, avoid breathing the stuff in, and wash it off anything it gets on. It should be storable in an airtight jar at room temperature without any problem. I keep my laser cartridges on a shelf in the store room, with no special provision. It is the drum in the cartridge that must be protected from light, not the toner.

If you want another source of this stuff, many machines have a bottle that collects waste toner, that must be replaced at the time the cartridge is replaced.

Let us know how it works, but be careful.

Roger

: My non-expert understanding is that toner is a very fine plastic power. When
: you make a copy the fuser roller heats it and melts it onto the paper. The
: image drum in your copier/laser printer is light sensative and the toner
: is heat sensative, but only at temperatures that would melt it. So I think
: storage in normal household conditions should be OK. The biggest problem
: that I see is that the stuff is messy if it spills.