How do you find the radius of exposure for H2S?

How do you find the radius of exposure for H2S?

for determining the 100-ppm radius of exposure: X = [(1.589)(hydrogen sulfide concentration)(Q)](0.6258), where “X” is the radius of exposure in feet, the “hydrogen sulfide concentration” is the decimal equivalent of the mole or volume fraction of hydrogen sulfide in the gaseous mixture and “Q” is the escape rate …

What is the exposure limit for H2S?

OSHA: The legal airborne permissible exposure limit (PEL) is 20 ppm not to be exceeded at any time, and 50 ppm as a maximum peak, not to be exceeded during any 10-minute work period. NIOSH: The recommended airborne exposure limit (REL) is 10 ppm, which should not be exceeded during any 10-minute work period.

What is rupture exposure radius?

For a flammable gas hazard, the rupture exposure radius refers to the horizontal distance from a leak source to the ½ Lower Flammable Limit (LFL).

How long can a person be exposed to hydrogen sulfide at a concentration of 1000 parts per million before he or she loses consciousness and stops breathing?

Staggering, collapse in 5 minutes. Serious damage to the eyes in 30 minutes. Death after 30-60 minutes. Rapid unconsciousness, “knockdown” or immediate collapse within 1 to 2 breaths, breathing stops.

What is the maximum average exposure to H2S you are allowed over an 8-hour period?

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 effect of exposure to 25 ppm of H2S for a few minutes?

In humans, inhalation of hydrogen sulfide at as low as 100-250 ppm for only a few minutes can result in incoordination, memory and motor dysfunction, and anosmia (so-called olfactory paralysis). Symptoms become more severe with longer exposure and sometimes lead to pulmonary edema.

At what ppm is hydrogen sulfide detectable?

Current hand-held detection equipment for hydrogen sulfide generally has a detection limit of 1 ppm, which is well above the odor threshold.

At what ppm is H2S flammable?

I.D.L.H. = Immediately Dangerous to Life and Health. S.T.E.L. H2S = 15 ppm Page 17 Exposure Limits Knocked out immediately, death in 35 minutes.

What is the maximum average exposure to H2S you are allowed over an 8 hour period?

Is H2S explosive when mixed with air?

Characteristics and health effects Hydrogen sulfide is explosive between the lower explosive limit of 4.3 percent — air is too lean to burn — and the upper explosive limits of 46 percent — air is too rich to burn. However, when mixed with air, the combination can be explosive if an ignition source is present.

What should you do if you are exposed to hydrogen sulfide?

Nitrite therapy (found in the cyanide antidote kit) has been suggested as a therapy for hydrogen sulfide exposure. Amyl nitrite is given by inhalation (for 30 seconds every minute until an intravenous line is established) followed by intravenous sodium nitrite (300 mg over absolutely no less than 5 minutes).

How do you calculate gas ppm?

Multiplying the number of moles of gas by the molar volume of gas (for a given temperature and pressure), we get the volume of gas in liters per cubic meter of total volume. Now we only need to express this volume in parts per million, thus obtaining the ppm value.

How do you neutralize hydrogen sulfide gas?

When dealing with a hydrogen sulfide gas leak, the National Oceanic and Atmospheric Administration recommends using water to spray down the gas, then adding sodium bicarbonate to neutralize it.