 Initial treatment for carbon monoxide poisoning is to immediately remove the person from the exposure without endangering further people . Those who are unconscious may require CPR on site . Administering oxygen via non @-@ rebreather mask shortens the half life of carbon monoxide from 320 minutes to 80 minutes on normal air . Oxygen hastens the dissociation of carbon monoxide from carboxyhemoglobin , thus turning it back into hemoglobin . Due to the possible severe effects in the fetus , pregnant women are treated with oxygen for longer periods of time than non @-@ pregnant people . 
