Brainstorm: make toxins useful again

[Sundance]

I have 2 idea's:

1: Let Centcom be a trader
Centcom would be a buyer of canisters of various mixes. This is pretty canon to me. Some hot, some cold, some high pressure, some with strange mixes. Canisters would be treated like crates, labelled and sent off, only coding-wise it would check it's atmospheric contents.

With the shortage of canisters as it is, unless there is a seller, this isn't really a good idea.

Gases.

Okay, so you want Chemistry II, immediately suggesting something as overpowered as Hydrogen. No. No no no. No. NO. Nope. Cease. Halt. Do not eat.

Well, I could support a visible gas causing burn damage.

Did you know??
1. There is the a canister manufacterer that makes empty canisters + everything else
2. Hydrogen is the first natural elemental gas that exists at room temperature
I didn't just suggest these things without thinking of it. What's wrong with toxins being similar to chemistry, only you have temperature has a major co-factor to how things are applied?