[cjbprime]

Why do you think it would be? If 200 humans share enough air to dilute the relative concentration of poison in that air effectively, none of those humans will receive lethal doses of poison.

[sureIy]

Only if the concentration reduces over time and the oil isn't enough to poison everyone in 69 seconds anyway.

The people can keep filtering a certain volume of oiled air, but at some point it's too much oil in their body.