Hydrogen sulfide is a colorless gas with the smell of rotten eggs. Its formula has uses in the chemical industry and is present in the decomposition of organic matter. Although it is found in small amounts in the human body, it has necessary properties and is a byproduct of various metabolic processes.
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What is Hydrogen Sulfide
This gas is known by different names such as hydrogen sulfide, hydrosulfuric acid, or sewer gas due to its odor. It is a hydroacid, meaning a non-metallic compound that contains hydrogen.
In the degradation of organic matter caused by bacteria, it is possible to detect hydrogen sulfide. Generally, it can be smelled in low concentrations without any instruments. However, as the concentration increases, it may become masked to the human nose because when it exceeds 5 ppm in the air, it has narcotic properties, posing a high health risk as it prevents detection through odor.
It can also occur due to bacterial degradation of organic matter under anaerobic conditions. It is also produced in oil refineries.
Properties
- Density greater than air, heavier.
- Flammable.
- Colorless.
- Odoriferous. Emits a smell similar to rotten eggs.
- Very toxic.
- Boiling point 212.86 K.
- Sweet taste.
Despite being naturally present in the body as an element involved in various functions, it is toxic in high concentrations. Nevertheless, it plays important roles.
Hydrogen Sulfide Formula and Nomenclature
It can also be found under the denomination or nomenclature of:
- H2Saq
Where it is Found Naturally
There are many places where its formation is spontaneous. Naturally, it is a component of petroleum and natural gas. It is also present in volcanic eruptions as a gas.
In areas with stagnant water and plant matter, it appears in varying concentrations depending on ventilation and the amount of decomposition. Thus, hydrogen sulfide can be found in flooded swamps, lakes, drains, and wells, but also in places where organic matter is processed and starts to decompose, such as fishing boats or in industries where fish oil is produced or tanks with meal are treated.
Uses
The application of hydrogen sulfide is closely related to the study of chemical reactions as it allows for precise identification of elements. The uses of hydrogen sulfide are:
- To analyze the composition of other materials and elements.
- Analytical chemistry to determine inorganic ions in solution during chemical processes.
- Tanning and leather treatment.
- Metal aging.
Although not intended for this purpose, some paints turn black due to its presence. When lead carbonate-based paints are exposed to air, plumbous sulfide or lead(II) sulfide may appear, giving a worn and neglected look. To prevent this, hydrogen peroxide 3, also known as oxygenated water, or other higher grades should be applied to stop the reaction.
This point is sometimes used to give an antique appearance to new materials. For this purpose, sodium sulfide is applied to bronze and leather.
So, What Is It Used For?
It is very common as a reagent in metal treatment. Hydrogen sulfide acts as a strong acid when it dissociates upon mixing with water, resulting in a pH below 1.
Is There a Hydrogen Sulfide Meter or Detector?
There are different models of devices designed to detect the early levels of this poisonous gas.
They generally feature an LED screen that displays the measurement and also an audible alarm to notify if the display is not constantly visible.
With a hydrogen sulfide detector, it is possible to measure the gas concentration in peak values, STEL, and TWA. These values can be analyzed based on the meter.
Toxicity
The toxicity is very high, and only 40 ml of hydrogen sulfide (hydrosulfuric acid) in an aqueous solution is enough to kill a human. Therefore, it must be handled with utmost care, and the safety data sheet and its guidelines should always be followed.
To prevent potential risks, it is important to have a hydrogen sulfide meter. This can detect the gas even before the odor is noticeable and, if detected, indicate whether the level is dangerous to human health.
The toxicity of hydrogen sulfide is high, both when present in liquid form and in the air. As little as 2 ppm in the air can be detected by the average person through smell. At 25 ppm in the air, it becomes lethal.
If you suspect someone may be affected by hydrogen sulfide, take them immediately to a cool and ventilated area and administer pure oxygen while seeking medical assistance.
At low levels, hydrogen sulfide exposure has the following effects:
- Irritation of mucous membranes.
- Causes throat irritation.
- Induces difficulty in breathing.
- Causes eye irritation.
- Fainting.
In asthmatic individuals, it can increase difficulty in breathing and trigger an asthma attack. The higher the dose received, the greater the chances of fainting and experiencing severe consequences.
Contact with the skin can cause frostbite burns. Therefore, protective gear such as gloves, masks, and safety goggles should be used when handling it.