MC is a health hazard.
So is sodium chloride, and dilute acetic acid, and even water if you happen to be under it. Not to mention cabbage, which is FULL of mutagenic and carcenogenic sulphur compunds.
MC is also a greenhouse gas, or ozone depleter, or both - I forget and can't be bothered to llok it up.
My first job was in a factory that ran activated carbon solvent recovery units that operated at WAY over 90% efficient, and the factory had at least one road tanker a week of MC, to top things up.
VERY nasty in a fire - you will get at least some phosgene generated.