Workplace engineering control for sulphur dioxide, an acid gas

It can be produced by the burning of coal, the source of most sulphur dioxide released into the environment.²

Because it can be inhaled in the general environment, much of the research on sulphur dioxide’s effect is concerned with people who have asthma.

Limited occupational studies

Information on SO² toxicity frequently relates to the effect of peak air pollution episodes rather than the long-term exposure that might be experienced by a worker.¹

However, SO² is a hazard found in many and varied workplaces. Case reports cited in the SO² recommendation by the Scientific Committee on Occupational Exposure Limits included paper manufacture, smelters and steel mills, aluminum manufacture, carpentry, maintenance, mining, refrigerant manufacture and wine making.¹

SO² toxicity 

SO² can affect the body if it is inhaled or comes into contact with the eyes or skin. It may cause severe breathing difficulties and may cause a person to stop breathing. Exposure of the eyes can cause a loss of vision.³

SO² rapidly forms sulfurous acid on contact with moist membranes of the human body. High concentrations may lead to paralysis of the respiratory system and fluid accumulation in the lungs, known as pulmonary edema.

If exposure is combined with certain particulates, the negative effects of SO² can be increased.³

SO² has not been found to cause cancer in humans.³

Permissible exposure limit (PEL)

NIOSH recommends workers’ exposure to SO² be limited to 2 ppm (parts per million) (5 mg/m³) TWA (time weighted average) over an 8-hour shift.

For short periods of time, the recommended exposure limit varies:⁵

Contact us

For information on acid gas filtration options for your chemical process, give us a call at 1.800.799.4609, email us at sales@sentryair.com, or fill out this online form to have a Sentry Air Systems Applications Specialist contact you to discuss your process.

Resources

¹Recommendation from the Scientific Committee on Occupational Exposure Limits for Sulphur Dioxide, updated December 2009http://ec.europa.eu/social/BlobServlet?docId=6410&langId=en

²Sulfur Dioxide, Wisconsin Department of Health Services
http://www.dhs/wisconsin.gov/eh/chemfs/fs/SulfurDioxide.htm

³Occupational Health Guideline for Sulfur Dioxide, OSHA
http://www.cdc.gov/niosh/docs/81-123/pdfs/0575.pdf

⁴Sulphur dioxide, CAS No 7446-095
Ces.lisc.ernet.in/energy/HC270799/HDL/ENV/enven/vol361.htm

⁵Documentation for Immediately Dangerous To Life or Health Concentrations (IDLHs) – Sulfur dioxide
http://www.cdc.gov/niosh/idlh/7446095.html