What is a safe LEL level H2S?
The Occupational Safety and Health Administration (OSHA) defines Permissible Exposure Limits (PELs) to H2S gas as follows: General Industry Ceiling Limit: 20 ppm. General Industry Peak Limit: 50 ppm (up to 10 minutes if no other exposure during shift) Construction 8-hour Limit: 10 ppm.
What is the LEL and UEL of H2S?
Flammability Range. U.E.L. H2S = 46% or 460,000 ppm. L.E.L. H2S = 4.3% or 43,000 ppm. Below 4.3% = Too Lean to Burn.
At what ppm is H2S explosive?
The gas can explode when its concentration in the air ranges from about 4% (40,000 ppm) to 46% (460,000 ppm).
How long can you work in 10 ppm H2S?
NIOSH: The recommended airborne exposure limit (REL) is 10 ppm, which should not be exceeded during any 10-minute work period.
How flammable is H2S?
Safety. Hydrogen sulfide is a highly toxic and flammable gas (flammable range: 4.3–46%).
What is lower explosive limit and upper explosive limit?
Lower explosive limit (LEL): the lowest concentration of gas or vapour which will burn or explode if ignited. Upper explosive limit (UEL): the highest concentration of gas or vapour which will burn or explode if ignited.
What temp does H2S become explosive?
450 °F
Hydrogen sulfide
| Names | |
|---|---|
| Flash point | −82.4 °C (−116.3 °F; 190.8 K) |
| Autoignition temperature | 232 °C (450 °F; 505 K) |
| Explosive limits | 4.3–46% |
| Lethal dose or concentration (LD, LC): |
What PPM does H2S stop smelling?
Health Hazards
| Concentration (ppm) | Symptoms/Effects |
|---|---|
| 0.00011-0.00033 | Typical background concentrations |
| 0.01-1.5 | Odor threshold (when rotten egg smell is first noticeable to some). Odor becomes more offensive at 3-5 ppm. Above 30 ppm, odor described as sweet or sickeningly sweet. |
How many ppm of H2S can you smell?
At what temperature does H2S spontaneously ignite?
roughly 518F
Hydrogen Sulfide is highly flammable, and at higher concentrations is also explosive. The temperature at which H2S will spontaneously ignite is roughly 518F. The tip of a cigarette burns at roughly 700F. When Hydrogen Sulfide is burned, it produces Sulfur Dioxide, which is another hazardous gas.
What is difference between LEL and UEL?
What are the dangers of H2S?
< 10 ppm: fairly harmless even though burning sensations can be felt in the eyes and lungs. This is the OSHA permissible exposure limit.
How many ppm of H2S is dangerous?
At higher concentrations of 200 to 300 ppm, hydrogen sulfide can be immediately life threatening. How likely is hydrogen sulfide to cause cancer? There are no studies that clearly show hydrogen sulfide causes cancer in humans or animals.
What are H2S exposure limits?
– avoiding areas that are known sources of hydrogen sulfide – keeping windows closed when the odour outdoors is noticeable and opening doors and windows once the outdoor odour has subsided – not exercising outdoors when the smell is present, particularly if your breathing rate increases.
Is H2S deadly?
h 2 s or hydrogen sulfide is one of the deadliest gases found in the petrochemical industry and poses serious hazards to the life and health if certain precautionary measures are not taken while working on the equipment which contains this, it is a colorless and highly flammable gas having a pungent odor, smells like a rotten egg and most widely …