Hydrogen sulfide: 5-10 ppB considered safe; 1200 ppb in the wind over the Gulf.
Benzine: 0-4 ppb considered safe; 3000 ppb in the wind over the Gulf .
Methelyne Chloride: 61 ppb considered safe; 3000 - 3400 ppb in the wind over the Gulf.
And nobody is even mentioning all the dihydrogen monoxide....