Sulfur Dioxide Information


Sulfur Dioxide:

Other Names

Sulfurous anhydride; sulfurous oxide; sulphur dioxide

Chemical Formula


CAS Number

7446 – 09 – 5

Industry Uses

Volcanic Activity; Fossil Fuels; Pharmaceuticals

Health Risks

Irritation; Respiratory Symptoms; Dermal Burns/Frostbite

Vapor Pressure

3.2 atm

Water Solubility

Slightly Soluble; Reacts with Water and Steam




Pungent, Irritating

Sulfur Dioxide MSDS

What is Sulfur Dioxide:

Sulfur Dioxide is a highly toxic, colorless gas that is non-flammable. It exists in all living species from bacteria to humans. Sulfur Dioxide is released naturally by volcanic activity and is produced as a by-product of the burning of fossil fuels contaminated with sulfur compounds. It is an environmental air pollutant. It is also used as a pharmaceutical aid and antioxidant, as well as a sanitizing agent for food containers and fermentation equipment. Sulfur Dioxide is heavier than air so fumes tend to travel along the ground. When exposed to heat or fire, containers of sulfur dioxide can explode and rocket.

Sulfur Dioxide Exposure and Health Risks:

Sulfur Dioxide is highly toxic when inhaled. Even very short exposures to small quantities can cause death. Sulfur Dioxide is a respiratory irritant, causing inflammation to nose, throat, and lungs, choking, coughing, discharge of nasal mucous, and bronchoconstriction if inhaled. Pulmonary edema, cyanosis, pneumonia, respiratory paralysis, and death can occur if exposure is severe. If directly contacted it can cause skin burns and/or frostbite.


The table below summarizes the most-recent exposure limits.





AEGL-1 (8 hrs)


0.75 ppm

AEGL-2 (8 hrs)


9.6 ppm

AEGL-3 (8 hrs)


5 ppm

TWA (8 hrs)


2 ppm

TWA (8 hrs)


5 ppm




Measuring Sulfur Dioxide:

Sulfur Dioxide concentration in the air can be measured in units of parts per million (ppm). Many of our products have digital communication capabilities for easy monitoring and control. We carry portable and fixed Sulfur Dioxide monitors and kits. All of our Sulfur Dioxide products can be viewed HERE.

What type of component are you looking for?

Fixed Mount Handheld Dissolved Kits:  Replacement Sensors: Calibration Gas:  Rentals: 

All sensors require a yearly calibration to ensure your gas measurements are accurate and performing within manufacturer standards. This page is desiccated to the individual manufacturers we represent and their specific calibration procedures. 

**Calibration Service Request Form **

Calibration Costs:

Calibration costs do vary, see below to get an estimate: 

Calibration Fee: $150

Analyzer Calibration Fee: $300

PM Calibration Sensor Fee: $330

Genie Calibration Fee: $265

ATI Calibration Fee: $205

** note that prices are subject to change per labor and parts required.

Contact us for help choosing the right monitor for your application