Information - Symptoms of H2S Poisoning by Parts Per Million (ppm)

Here is a handy chart indicating the symptoms associated with various levels of H2S.

L O W	0 - 10 ppm	Irritation of the eyes, nose and throat
M O D	10 - 50 ppm	Headache Dizziness Nausea and vomiting Coughing and breathing difficulty
H I G H	50 - 200 ppm	Severe respiratory tract irritation Eye irritation / acute conjunctivitis Shock Convulsions Coma Death in severe cases