Hydrogen Sulphide

Introduction

Hydrogen sulfide is a colourless, poisonous and flammable gas with the smell of rotten eggs. It can be detected by smell at very low concentrations ranging from 0.01 - 0.3 parts per million. Detection by odour is not reliable because at high concentrations (e.g. 100 ppm), hydrogen sulfide deadens a person's sense of smell thus make it non-detectable.

Hydrogen sulfide is very quickly absorbed into the lungs. Short term exposure may cause irritation of nose, throat, eyes and lungs.

H2S Hazards

Hydrogen sulfide is an extremely toxic gas which has been responsible for numerous fatalities, and in the case of Japan it is believed to be the most common cause of volcanic gas accidents (at least 10 incidents since the early 20th century). This has led many volcano observatories in Japan to install H2S detectors and automated warning systems.

One such incident occurred in 1971 on the flanks of Kusatsu-Shirana volcano, Honshu, when six downhill skiers died almost instantly after passing through a depression filled with H2S. Being denser than air, the gas may accumulate in snow-covered depressions or caves which are breached from time to time, releasing lethal concentrations to the surface. Another more recent accident occurred on Adatara volcano, Honshu, a basaltic to andesitic volcano which forms part of the volcanic front of northeastern Japan. On September 15, 1997, 4 hikers, from a party of 14, were killed after inhaling volcanic gases on the floor of the Numano-taira crater. The group had become disoriented because of fog and left the trail, which had signs warning of volcanic gas hazards in the area. Three of the hikers fell into the crater where they succumbed to noxious gases that had accumulated on the crater floor due to calm wind conditions. The fourth hiker killed also succumbed to the gases while attempting a rescue. Scientists from the Kusatsu-Shirane Volcano Observatory reported that the fumarolic gas from the southwest rim of the crater was composed of 0.5% SO2, 33-37% CO2, and 60-65% H2S.

Responsibilities

Supervisors

Identify research projects and experiments that use hydrogen sulfide.

Assess hazards associated with the use of hydrogen sulfide in the specific project or experiment.

Implement engineering controls; develop safe work procedures and personal protective equipment to address the identified hazards.

Implement emergency response procedures that provide clear instructions on actions to take in the event of an emergency

Train all workers that work with hydrogen sulfide so they understand the hazards associated with the use of hydrogen sulfide and the safe work procedures.

Ensure others present in the laboratory are aware of hydrogen sulfide hazards and the emergency response procedure.

Maintain records of all training provided.

Laboratory Workers

All workers using hydrogen sulfide must participate in training and follow the established safe work procedures.

Department Heads

Ensure the elements identified in this Code of Practice are implemented.

Approve safe work procedures

Environmental Health & Safety

Assists departments in the development of safe work procedures, training and other matters related to the health & safety of University staff.

Provide current regulatory information updates necessary for compliance with Occupational Health & ...