Introduction to Chlorine Dioxide (ClO2)

Chlorine Dioxide (ClO2) is a yellowish-green gas that is a potent and useful oxidizing agent used in water treatment and in bleaching. Used most often as to bleach paper, it produces a clearer and stronger fiber and produces less harmful by products than Chlorine. It can be used for air disinfection and was the principal agent used in the decontamination of buildings in the United States after the 2001 anthrax attacks.

In addition, Chlorine Dioxide is a preoxidant to control tastes and odor. Chlorine Dioxide is used as a fumigant treatment to sanitize fruits such as blueberries, raspberries, and strawberries that develop molds and yeast.

As Chlorine Dioxide is a toxic gas, any personnel working with it should be provided with and required to use impervious clothing, gloves, face shields, and other appropriate protective clothing necessary to prevent exposure. In the event of a leakage, accurate detection and alarming are required before hazardous levels are reached.

Health Hazards

When present in high concentrations, Chlorine Dioxide may produce these symptoms:

  • Eye, nose, throat, respiratory irritation
  • Coughing and wheezing
  • Shortness of breath
  • Pulmonary edema (excess fluid in lung tissue)

Exposure Limits

When researching ClO2 gas detection solutions, facility managers should be aware of the following ClO2 exposure limits:

Exposure Limits Agency
0.1 ppm TWA OSHA PEL (General Industry)
0.1 ppm TWA OSHA PEL (Construction Industry)
0.1 ppm TWA, 0.3 ppm STEL ACGIH TLV
0.1 ppm TWA, 0.3 ppm STEL NIOSH REL

Technology for ClO2 Gas Detection

Electrochemical Sensors

Electrochemical sensors are fuel cell-like devices consisting of an anode, cathode, and electrolyte. The components of the cell are selected so that a subject gas, allowed to diffuse into the cell, will cause a chemical reaction and generate a current. The cells are diffusion-limited, meaning that the rate of the gas entering the cell is solely dependent on the gas concentration. The current generated is proportional to the rate of consumption of the subject gas in the cell.

Learn more about the advantages of using Sierra Monitor's electrochemical gas sensor modules »