Hydrogen Sulfide: NIOSH 6013

Method Application:

This method is used for personnel and area monitoring to determine human exposure levels to Hydrogen sulfide in air for OSHA compliance. Analysis is performed with an ion chromatograph equipped with a conductivity detector. Air samples are collected at 0.1 to 1.5 L/minute for a sample size of 1.2 L to 40 L using a 25-mm, 0.45 μm PTFE filter with a porous plastic support pad housed in a polystyrene cassette followed by a 400/200 mg specially treated activated charcoal tube, Supelco Orbo 34.

Hydrogen sulfide is a colorless, flammable, extremely hazardous gas with a "rotten egg" smell. Some common names for the gas include sewer gas, stink damp, swamp gas, and manure gas. It is heavier than air and therefore accumulates at the bottom of poorly ventilated areas. Hydrogen sulfide is both an irritant and a chemical asphyxiant with human health effects relating to oxygen utilization and the central nervous system. Its health effects do vary depending on the level and duration of exposure. Repeated exposure can result in negative health effects occurring at levels that are tolerable under single exposure conditions without any effect.

Market Application:

Hydrogen sulfide occurs naturally in crude petroleum, natural gas, hot springs, volcanoes and underwater thermal events. Hydrogen sulfide is also produced by bacterial breakdown of organic materials, and human and animal wastes (e.g., sewage).

Industrial activities that can produce the gas include petroleum/natural gas drilling and refining, wastewater treatment, coke ovens, tanneries, Rayon textile production, pulp and paper mills, chemical manufacturing, and waste disposal facilities.

Advantages:

NIOSH 6013 has been improved by introducing a sodium carbonate/bicarbonate eluent that has a longer shelf life. It eliminates the retention of the phosphate ion on the column and decreases the noise level. In addition, the charcoal tubes have been replaced with specially treated activated coconut shell charcoal tubes, ORBO-34. These tubes have been shown to contain consistently low sulfate background. Methyl and Ethyl mercaptan do not interfere with the analysis. However, sulfur dioxide can provide a positive interference.

OSHA PELs for:

• Construction Industry: 10 ppm, 15 mg/m³ TWA
• Maritime: 10 ppm, 15 mg/m³ TWA
• General Industry: 20 ppm (Ceiling); 50 ppm (Peak)