To the contrary: in the long past a non-flamable and to my knowledge non-toxic gas was used.
With its effect on the Stratosphere realized alternatives had to be used.
My favorite aerosol canister : none. It doesn't take long before you've already thrown away more money and air than a decent mid-quality small aircompressor and filter system costs (typically around $300 - much less than that and you get an expendable toy running hot and noisy because it's too revved up to make up for a cheapo motor and pump - NEVER believe HP ratings on home center or big box compressors - they're total BS).