Chlorine is used in many applications including water disinfection and for treating sewage effluent, bleaching of pulp in paper mills, disinfecting of equipment and utensils in beverage and food processing plants and is used in the manufacture of a number of products including rubber, antifreeze, household cleaning agents, and pharmaceuticals. In addition, one of the most common uses of chlorine is to keep pool water safe for swimming. Most of us use products that contain chlorine on a regular basis without concern. However, in many industrial applications, chlorine can cause worker illness, injury, and even death.

Hazard Summary: Chlorine is a strong irritant in humans affecting the eyes, upper respiratory tract, and the lungs. Exposure to various concentrations have reported to have varying effects as the concentration increases. Physical effects at sub ppm levels include tickling of the nose and throat to stinging or dryness of the nose and throat, and burning of the conjunctiva. At levels from 1 ppm there is discomfort ranging from ocular and respiratory irritation to coughing, shortness of breath, and headaches. High levels of chlorine exposure have resulted in the following effects in humans; 1 to 3 ppm; mild mucous membrane irritation; 30 ppm; chest pain, vomiting, shortness of breath, cough; 46 to 60 ppm; toxic pneumonitis and pulmonary edema; 430 ppm; lethal after 30 minutes; 1000 ppm fatal within a few minutes.


Physical Properties of Chlorine: Chlorine is a greenish yellow gas that is slightly soluble in water, has a pungent irritating odour, and is 2.47 times heavier than air. Chlorine is a strong oxidizer that reacts explosively or forms explosive compounds with many common substances such as acetylene, ether, turpentine, ammonia, fuel gas, hydrogen, and finely divided metals.

Chlorine Monitoring: When monitoring for the presence of chlorine gas, several factors need to be considered to determine the proper type of monitoring instruments required. For chlorine gas that may be present within a confined space, generally a personal portable or a portable sample drawing instrument work best. The instrument or hose can be lowered into the space to determine if chlorine gas is present. When using sample drawing instruments for the detection of chlorine, Teflon lined hoses must be used to prevent absorption and loss of sample. Remember when monitoring, chlorine gas is heavier than air and may settle in low lying areas. Record keeping is extremely important when monitoring for gases such as chlorine. Instruments such as the ToxiPro and PHD6 are provided with data logging circuitry which can be used to track exposure to chlorine and other gases present. In addition, Time Weighted Average and Short Term Exposure Limit alarms are present to protect the worker from over exposure.

When plant wide monitoring for chlorine on a continuous basis is required, continuous monitoring systems such as the D-Guard and MicroRackssystems should be used. Any one of these systems can easily be configured for the detection of chlorine gas. Utilizing the D-Guard gas transmitters for chlorine, customers can place these gas transmitters throughout their plant including breathing zone, gas cabinets, gas storage areas, and process rooms where chlorine is used. The Smart Sensor Technology used on the D-Guard transmitter allows the user to purchase pre-calibrated sensors to simplify calibration and maintenance. For more information on GasTech instruments for chlorine detection, portable gas detection instruments, fixed systems, and the D-Guard transmitters, please contact GasTech on our Toll Free Sales line:1800 999 902.