What is LEL & UEL?

What is LEL & UEL?

The minimum concentration of a particular combustible gas or vapor necessary to support its combustion in air is defined as the Lower Explosive Limit (LEL) for that gas. The maximum concentration of a gas or vapor that will burn in air is defined as the Upper Explosive Limit (UEL).

What is Lel of H2S?

L.E.L. H2S = 4.3% or 43,000 ppm.

What level of H2S is lethal?

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.

How can you protect yourself from H2S?

Severe Inhalation Exposure Causing Collapse

1. Call 911.
2. Before helping hurt person, protect yourself by using non-entry procedures if possible, or by wearing a full-face piece breathing apparatus before entering hazardous space.
3. Get person to fresh air.
4. Begin CPR if trained.
5. Transfer immediately to a medical facility.

What does hydrogen sulfide do to the body?

H2S irritates the mucous membranes of the body and the respiratory tract, among other things. Following exposure, short-term, or acute, symptoms may include a headache, nausea, convulsions, and eye and skin irritation. Injury to the central nervous system can be immediate and serious after exposure.

What happens if you breathe H2S?

The health effects of hydrogen sulfide depend on how much H2S a worker breathes and for how long. However, many effects are seen even at low concentrations. Effects range from mild, headaches or eye irritation, to very serious, unconsciousness and death.

How long does hydrogen sulfide stay in your system?

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.

Can sewage smell be dangerous?

While sewer gas isn’t dangerous in small amounts, these compounds contribute to sewer gas toxicity at high levels. Hydrogen sulfide is the primary gas in sewer gas. According to research , hydrogen sulfide has shown to be toxic to the oxygen systems of the body. At higher levels, ammonia is toxic to humans.

Is hydrogen sulfide safe to drink?

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.