The U.S. Department of Health and Human Services (DHHS) and the International Agency for Research on Cancer (IARC) have not classified H2S as to its ability to cause cancer.
Hydrogen sulfide (H2S) is a colorless, flammable gas at ambient temperature and pressure. It has an odor similar to that of rotten eggs and is both an irritant and an asphyxiant. The air odor threshold ranges between 0.008 and 0.13 ppm, and olfactory fatigue may occur at 100 ppm.
H2S is immediately fatal when concentrations are over 500-1000 parts per million (ppm) but exposure to lower concentrations, such as 10-500 ppm, can cause various respiratory symptoms that range from rhinitis to acute respiratory failure.
Hydrogen sulfide air concentrations from natural sources range between 0.00011 and 0.00033 ppm. In urban areas, the air concentrations are generally less than 0.001 ppm. Hydrogen sulfide remains in the atmosphere for approximately 1–42 days, depending on the season.
H2S does not accumulate in the body, but repeated/prolonged exposure to moderate levels can cause low blood pressure, headache, loss of appetite and weight loss. Repeated exposure over time to high levels of H2S may cause convulsions, coma, brain and heart damage, even death.
Prolonged exposure may cause nausea, tearing of the eyes, headaches or loss of sleep. Airway problems (bronchial constriction) in some asthma patients. Possible fatigue, loss of appetite, headache, irritability, poor memory, dizziness. Slight conjunctivitis ("gas eye") and respiratory tract irritation after 1 hour.
Control Exposures
- Use exhaust and ventilation systems to reduce hydrogen sulfide levels.
- Train and educate workers about hazards and controls.
- Establish proper rescue procedures to safely rescue someone from a hydrogen sulfide exposure.
- Use respiratory and other personal protective equipment.
People can smell the “rotten egg” odor of hydrogen sulfide at low concentrations in air. However, with continuous low-level expo- sure, or at high concentrations, a person loses his/her ability to smell the gas even though it is still present (olfactory fatigue).
Symptoms of acute exposure include nausea, headaches, delirium, disturbed equilibrium, tremors, convulsions, and skin and eye irritation. Inhalation of high concentrations of hydrogen sulfide can produce extremely rapid unconsciousness and death. Exposure to the liquified gas can cause frostbite injury.
While such concentrations are rare, hydrogen sulfide's presence in drinking water, when released in confined areas, has been known to cause nausea, illness and, in extreme cases, death. Water with hydrogen sulfide alone does not cause disease.
At low levels, hydrogen sulfide gas has a strong odor similar to rotten eggs. However, at higher levels, your nose can become overwhelmed by the gas and you cannot smell it. At higher levels, hydrogen sulfide gas can make you sick and could be fatal.
Lead acetate test strips are a cheap & simple method of hydrogen sulfide detection in both water & air. Simply dip in water & check for a color change. To measure H2S gas in air, wet the strip first; if present, the strip will change color.
The largest 100 ppm H2S concentration hazard zone for platforms located in the eastern Santa Barbara Channel (Platforms Gail, Gilda, Grace, and Gina) has a maximum downwind distance of 813 feet.
Hydrogen sulfide is found naturally in crude petroleum and natural gas. It is also produced through the bacterial breakdown of organic matter. Hydrogen sulfide can be produced by decomposing human and animal waste, and is found in sewage treatment plants and livestock areas.
Hydrogen sulfide is produced naturally by decaying organic matter and is released from crude petroleum, natural gas, volcanic gases, liquid manure, sewage sludge, landfills, and sulfur hot springs. Hydrogen sulfide is slightly heavier than air and may accumulate in enclosed, poorly ventilated, and low-lying areas.
TREATMENT OPTION: AERATIONBecause hydrogen sulfide gas escapes rapidly from water to cause an odor, it may also be removed from the water by aeration. The process includes bubbling air through the water tank, then separating or "stripping" the hydrogen sulfide in the air by venting it to the outdoors.
You might try filling the washer with hot water and you usual soap. Let it run for a few minutes then add 1 cup vinegar and a box of baking soda. Let it run for a few minutes then stop it and let it soak for 20 to 30 minutes. Then let it finish the wash cycle.
Hydrogen sulfide is used primarily to produce sulfuric acid and sulfur. It is also used to create a variety of inorganic sulfides used to create pesticides, leather, dyes, and pharmaceuticals. Hydrogen sulfide is used to produce heavy water for nuclear power plants (like CANDU reactors specifically).
OSHA designates that personal monitors for atmospheric monitoring, including H2S monitors, should be worn within what is called the breathing zone. The breathing zone is 9 inches from the mouth and nose but not behind the shoulders.
Physical Properties of H2S
- Visibility. H2S is colourless and has a reflective ratio very similar to that of air making it extremely difficult for our eyes to detect.
- Boiling Point. With a boiling point of -60.4 degrees Celsius it is typically found in a gaseous state.
- Density.
- Flammable.
- Explosive.
- Dissolves in Water.
- Corrosiveness.
- Smell.
The Cause Of The Rotten Egg SmellThe reason your water probably smells like rotten eggs is because it contains some traces of hydrogen sulfide. In most cases this smell occurs due to a build-up of hydrogen sulfide in your hot water heater.
This course is intended for anyone currently working or wanting to work in the Oil & Gas Industry. The goal of H2S Alive is to prepare workers to recognize H2S (hydrogen sulfide) hazards and protect themselves, as well as perform a basic rescue during an H2S incident.
Sulfate-reducing bacteria are the main producer of hydrogen sulfide in the gut. High concentrations of hydrogen sulfide are involved in gut inflammation. Lactic acid bacteria can be sensitive to hydrogen sulfide.
