NPI: Hydrogen sulfide fact sheet (original) (raw)

Ecogen power station Photo: John Baker

The National Pollutant Inventory (NPI) provides information on the types and amounts of pollutants being emitted in the Australian community.

This page provides facts about hydrogen sulfide. It describes how you might be exposed to this substance, how exposure might effect you and the environment, common uses, comparative data about hydrogen sulfide and its physical and chemical properties.

For more information about some of the terms used in this page, see the NPI glossary.

The National Pollutant Inventory (NPI) holds data for all sources of hydrogen sulfide emissions in Australia.

Health effects

What effect might hydrogen sulfide have on my health?

Collapse, coma and death from respiratory failure may come within a few seconds after one or two inspirations, at high levels (concentrations of 1000 to 2000 parts per million). Concentrations of 100 to 200 parts per million for one to eight hours may cause sleeplessness, blurred vision, haemorrhage and death. Lower concentrations may irritate the eyes, nose and throat (5 to 50 parts per million). Following an exposure there may be headaches, dizziness, and nausea. Repeated exposures may cause headaches, anorexia, insomnia, paralysis, meningitis, psychic troubles, slowed heart rate, bronchitis and a grey-green line on the gums.

How might hydrogen sulfide enter my body?

Hydrogen sulfide can enter the body when a person breathes air containing hydrogen sulfide. This is most common for people who work in areas of higher exposure or near to facilities where hydrogen sulfide are used or produced.

How might I be exposed to hydrogen sulfide?

Workers in the industries that use or produce hydrogen sulfide are most at risk of exposure. Consumers can be exposed to hydrogen sulfide by exposure to air from production and processing facilities that use or produce hydrogen sulfide such as mining operations, chemical processing facilities, oil and gas extraction operations, electric power plants, pulp and paper mills, and other producers of to hydrogen sulfide.

See Sources for more information.

What are the hydrogen sulfide health guidelines?

Worksafe Australia: For hydrogen sulfide, it is allowable for workers to be exposed to concentrations of 10 parts per million, averaged over an eight hour workshift, with the exposure not exceeding 15 parts per million. Worksafe Australia reports hydrogen sulfide is very toxic by inhalation.

Australian Drinking Water Quality Guidelines (NHMRC and ARMCANZ, 1996):
Aesthetic
Maximum of 0.05 mg/L (i.e. 0.00005 g/L).

The Australian NOHSC National Exposure Standards Database link is probably the most useful source of information.

Note that the emissions data in the NPI database is not directly comparable with these guidelines.

Environmental effects

What effect might hydrogen sulfide have on the environment?

Hydrogen sulfide has high acute (short-term) toxicity to aquatic life, birds, and animals. Insufficient data are available to evaluate the acute toxicity of hydrogen sulfide on plants on land. Insufficient data are available to evaluate the chronic toxicity of hydrogen sulfide to plants, birds or animals.

How might hydrogen sulfide enter the environment?

Hydrogen sulfide will be in the atmosphere as a gas. It will be dispersed depending upon where the air currents carry it. It breaks down in the air in a few days.

Where in the environment does hydrogen sulfide end up?

Hydrogen sulfide enters the environment from both natural and human processes. Almost all the releases are to the air, where it exists in the gas phase. In the air it will react with other chemicals to be broken down, it will usually be broken down in about three days.

What are the hydrogen sulfide environmental guidelines?

No national guidelines.

Common uses

Hydrogen sulfide is used in the manufacture of pulp and paper (digesting agent), in tanneries and in sulfide ores. Most man made hydrogen sulfide is produced as a by-product of industry, rather than for industry.

Sources of emissions

Industry sources

Potential large emitters of hydrogen sulfide are electric power plants (burning coal or fuel oil containing sulfur), oil and gas extraction operations, oil refineries, pulp and paper mills, sewage treatment plants, large pig farms and other confined animal feeding operations, Portland cement kilns, municipal waste landfills, coke ovens, sulfur products and hydrogen sulfide production, asphalt production and storage and geothermal power plants. Most hydrogen sulfide releases are to the air.

Diffuse sources, and industry sources included in diffuse emissions data

Other potential emitters of hydrogen sulfide are breweries, fertiliser producers, glue manufacturers, processing of ores (Lead, gold, and copper) and sugar beet and sugar cane processing.

Natural sources

Hydrogen sulfide is found in coal pits, volcanic gases, natural gas wells, sulfur springs, and decaying organic matter which contains sulfur.

Transport sources

Found in car exhaust.

Consumer products that may contain hydrogen sulfide

It is not believed that there are any consumer products that contain hydrogen sulfide. Some consumer products may release hydrogen sulfide, such as septic tanks and the burning of coal or oil.

Comparison to other substances

NPI rank

Approximately 400 substances were considered for inclusion on the NPI reporting list. A ranking and total hazard score was given based on health and environmental hazards and human and environmental exposure to the substance.

Hydrogen sulfide was ranked as 37 out of 400. The total hazard score taking into account both human health and environmental criteria is 3.5.

On a health hazard rating of 0 - 3 hydrogen sulfide registers 1.8. A score of 3 represents a very high hazard to health, 2 represents a medium hazard and 1 is harmful to health.

On an environmental rating of 0 - 3 hydrogen sulfide registers 1.7. A score of 3 represents a very high hazard to the environment and 0 a negligible hazard.

Factors taken into account to obtain this ranking and these scores include the extent of the material's toxic or poisonous nature and/or its lack of toxicity, and the measure of its ability to remain active in the environment and whether it accumulates in living organisms. It does not take into account exposure to the substance. Environmental exposure is reflected in the NPI rank for this substance (see comparative data below). A substance that scores highly as an environmental hazard is oxides of nitrogen at 3.0 and one of the lower scores is carbon monoxide at 0.8. A substance that scores highly as a health hazard is arsenic at 2.3 and one of the lowest scores is ammonia at 1.0.

Total hazard rating

Physical and chemical properties

Substance name Hydrogen sulfide
CASR number 7783-06-4
Molecular formula H2S
Synonyms Hydrogen sulphide; Hydrosulfuric acid; heptic acid; Stink Damp; Sulfureted Hydrogen; Sulfur Hydride; Sewer gas; sour gas; Sulferetted hydrogen
**Physical properties:**Melting Point (�C): -85.4Boiling Point (�C): -60.3Vapour Density: 1.189
**Chemical properties:**Hydrogen sulfide is a colourless, flammable, poisonous gas that smells like rotten eggs. It is soluble in water and organic solvents and will corrode metals.Flashpoint (�C): -82.4

Sources of information used in preparing this fact sheet

Worksafe Australia (1996), Hazardous Substance Hydrogen sulphide (accessed, May, 1999)

There is more information that may be useful in understanding some of the issues surrounding the NPI.