I had a summer job at a hospital one year in the data center when an electrician managed to trigger the halon system and we all had to evacuate and wait for the process to finish and the gas to vent. The four firetrucks and station master who shoved up was both annoyed and relieved it was not real.

Not sure if you’re joking but a relatively small datacenter I’m familiar with has reduced oxygen in it to prevent fires. If you were to break in unannounced you would faint or maybe worse (?).

Halon was used back in the day for fire suppression but I thought it was only dangerous at high enough concentrations to suffocate you by displacing oxygen.

No FM200 isn't poisonous.

And lasers come to think of it