Sulphur Dioxide (SO2)

UNICERT is the leading inspection body in the area of Air Quality test for Sulfur dioxide (SO2) and its objectives are to reduce environmental emission/pollution and to enhance the environmental performance of society.

Sulfur dioxide (SO2):

Sulfur dioxide (also sulphur dioxide in British English) is the chemical compound with the formula SO2. It is a toxic gas with a burnt match smell. It is released naturally by volcanic activity and is produced as a by-product of the burning of fossil fuels contaminated with sulfur compounds and copper extraction.

Sulfur dioxide is an intermediate in the production of sulfuric acid, being converted to sulfur trioxide, and then to oleum, which is made into sulfuric acid. Sulfur dioxide for this purpose is made when sulfur combines with oxygen.

In 2008, the American Conference of Governmental Industrial Hygienists reduced the short-term exposure limit to 0.25 parts per million (ppm). The OSHA PEL is currently set at 5 ppm (13 mg/m3) time-weighted average. NIOSH has set the IDLH at 100 ppm. In 2010, the EPA “revised the primary SO2 NAAQS by establishing a new one-hour standard at a level of 75 parts per billion (ppb). EPA revoked the two existing primary standards because they would not provide additional public health protection given a one-hour standard at 75 ppb.


What are the effects of SO2 on human health?

Sulfur dioxide affects human health when it is breathed in. It irritates the nose, throat, and airways to cause coughing, wheezing, shortness of breath, or a tight feeling around the chest. The effects of sulfur dioxide are felt very quickly and most people would feel the worst symptoms in 10 or 15 minutes after breathing it in.

Those most at risk of developing problems if they are exposed to sulfur dioxide are people with asthma or similar conditions. Inhaling sulfur dioxide is associated with increased respiratory symptoms and disease, difficulty in breathing, and premature death.


What are the environmental effects of SO2?

At high concentrations, gaseous SOx(SO2) can harm trees and plants by damaging foliage and decreasing growth. SO2 and other sulfur oxides can contribute to acid rain which can harm sensitive ecosystems.


Interested Parties including Regulatory Authorities:

    1. Persons affected by SO2
    2. Industries, Laboratories using/ Generating SO2
    3. Warehouses Containing Chemicals of SO2
    4. Motor Vehicles for personal and commercial uses
    5. Private / Govt. Projects to control SO2
    6. Handling and transportation of chemical containing SO2
    7. Local Environmental Department/ Authorities
    8. Local Government Authorities like Municipalities, City Corporation etc.
    9. Local Law Enforcing Agencies like Police, Magistrate and Regulatory Authorities etc.


Benefits of Monitoring:

By monitoring long-term contamination trends, every country establishes baseline contamination levels, making it possible for early identification of contamination events. Daily events and long term trends are captured and steps are taken to reduce environmental emission/ pollution and enhance the environmental performance of society.