Bob,

Whether death can occur from just one breath is debatable, but many sites make such a claim, just Google "sour gas".

There are plenty of documented cases of H2S induced death, particularly in the gas drilling industry.

Above 20 ppm you start to lose your ability to detect it by smell, exposures at 250 and above can cause pulmonary edema possibly resulting in a delayed death,  and when you get into the 500-1000 ppm the effects include - respiratory paralysis, irregular heartbeat, collapse, and death.

W.

Wayne Wood | Associate Director, University Safety (EHS) - Directeur Adjoint, Direction de la prévention (SSE), Services universitaires | McGill University | 3610 McTavish Street, 4th floor | Montreal, Quebec, Canada, H3A 1Y2 | Tel: (514) 398-2391 | Fax: (514) 398-8047

-----Original Message-----
From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU] On Behalf Of Secretary, ACS Division of Chemical Health and Safety
Sent: Monday, October 03, 2011 11:10 AM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: Re: [DCHAS-L] H2S Antidotes

From: "Bob Weeks" 
Subject: RE: [DCHAS-L] H2S Antidotes
I have heard that one breath of hydrogen sulfide is fatal. Is there any documentation concerning this?

Thank you.

Robert Weeks, PhD, CIH