The management of the Hotel Grand Chancellor in Auckland called the firefighters to report a very strong odor of rotten eggs which escaped from the chamber of Ivil Mark Lawrence. He has deposited on his door a note indicating the presence of toxic gases inside. First aid therefore donned their NRBC outfits to enter the room and found one man, a source of hydrogen sulfide still active beside him. Other chemicals were found in the room. Part of the hotel was evacuated and if half a dozen people have received emergency care, none suffered from serious health problems. The man was showered in order to remove the chemicals but he could not be resuscitated. A specialized team was asked to decontaminate the room.
Hydrogen sulphide or H2S
Smell. Each of us remembers the characteristic smell of rotten eggs released during the synthesis of hydrogen sulphide during the course of chemistry! This is a colorless gas found naturally in coal, oil or natural gas. Bacteria synthesize it by anaerobic fermentation of sulfur products. It is also found in the chemical industry sulfur compounds. The fermentation of green algae that multiply on Brittany beaches emit deadly hydrogen sulfide.
The odor is detectable at very low concentrations (0.001 to 0.13 ppm). Although these concentrations are below the toxic concentrations the use of sensors is nonetheless recommended where there is a possibility of exposure because at higher concentrations the olfactory nerve can be inhibiter and the detection through the nose is no longer possible.
Flammable, it could cause an explosion if present in concentrations of between 4.3 and 46%. By burning it mainly produces sulfur dioxide.
Heavier than air, it accumulates in the cavities, holes and height differences.
Mortality. Many deaths have been described in the workplace or not. Deaths may be multiple, the rescuers being vulnerable if they don’t follow the recommendations that were given to them.
Toxicology. It is mainly absorbed in the respiratory tract. At lethal concentrations it effects in humans are in seconds to minutes. H2S inhibits enzymes containing metal ions such as cytochrome oxidase: cellular respiration is stopped. The tissues that need most oxygen being the heart and nervous tissues, they are the most susceptible to H2S. Headache, nausea, dizziness, rapid breathing, restlessness, convulsions and loss of consciousness are the main symptoms of intoxication. When the concentration is greater than 1 000 ppm, death occurs within minutes by paralysis of the respiratory centers.
It is irritating to eyes.
If inhaled gas, the person must be brought in a ventilated area. If not breathing, mouth to mouth is banned to avoid inhaling exhaled gas. The patient is put on oxygen and monitored in hospital because the pulmonary edema may be delayed.
Personal protective equipment
The main protection is a full face canister and eye protection. The equipment can be completed by a protective suit of skin.
To collect green algae on the beaches, an interesting article of AFSSA describes the required equipment for the handling it.
The Polycombi equipment of Ouvry is well adapted to this situation, especially because the breathability of the fabric allows a much longer time of work compared to the tight outfits.
The chemical suicide
This type of suicide is much more common than it seems. There were more than 800 cases in Japan in 2009. The production of H2S is carried out by mixing an acid with a sulfur-containing product (some household products are well suited to this kind of mixture!). Japan forced several Internet websites to remove the recipe to produce H2S.
The place of suicide is generally relatively small and confined (passenger car). The first responders must consider a number of relatively well-defined signs : window and doors closed, tape on the joints, open containers and chemical products or their packaging close, smell of rotten eggs, presence of people who have difficulty breathing nearby. What is most strange is that the vast majority of suicide leave a note indicating the presence of chemicals!
It is evident that this type of suicide implies actions from the first responders and particularly the use of PPE.
More on this excellent report: http://www.npstc.org/documents/h2s%20report%20for%204112.pdf