Understanding Certifications for Gas Detection Equipment

November 4, 2021
Understanding Certifications for Gas Detection Equipment

Hazards are present across a variety of industries and applications, but are specifically defined as an area where combustible or flammable material is or has the potential to be present. These dangerous locations are classified by their type of combustible risk and the likelihood of it being present in the area. Classifications are determined by standards set by the National Electric Code (NEC) in the United States and internationally by the International Electrochemical Commissions (IEC). 

A hazardous area is defined in one of two ways: either the Class/Division system in North America or the Zone system which is recognized internationally. The Class/Division certification system will occasionally use a Minimum Ignition Current (MIC) ratio when measuring. The MIC ratio is the least amount of current generated from an inductive spark, necessary to ignite the easiest concentration of the target gas in the air by the minimum current from an inductive spark, required to ignite the easiest concentration of methane in the air. 

The Class/Division system is organized in the following way:

  • Classes
    • Class I: gas
    • Class II: dust
    • Class III: fibers
  • Divisions
    • Division I: a hazard likely to be present during normal operating conditions
    • Division II: a hazard present during abnormal conditions like a spill or leak

This system also defines Groups A through G, which identifies the particular hazard of concern. For example:

  • Group A: Acetylene
  • Group B: Hydrogen, butadiene, ethylene oxide, propylene oxide, acrolein, and other gases with a MIC ratio less than 0.40
  • Group C: Ethyl ether, ethylene, acetaldehyde, cyclopropane, and other gases with a MIC ratio greater than 0.40 but less than 0.80
  • Group D: Acetone, ammonia, benzene, butane, ethanol, gasoline, methane, natural as, naphtha, propane, and other gases with a MIC ratio greater than 0.80
  • Group E: Combustible metal dusts including aluminum, magnesium and alloys of aluminum and magnesium
  • Group F: Combustible carbonaceous dusts containing more than 8% volatile compounds such as carbon black, coal and coke dust
  • Group G: Combustible dusts such as flour, starch, grain, wood, plastic, chemicals, and other combustible dusts not included in groups E or F

The more modern international system defines areas by zones and groups:

  • Zones: define the likelihood of the hazard to be present
    • Zone 0: The hazard is present continuously and for long periods of time
    • Zone 1: The hazard is likely to be present in normal operating conditions
    • Zone 2: The hazard is not likely to be present in normal conditions for an extended period of time
  • Groups: tell you the particular type of hazard
    • Group I: the hazard is specific to the mining industry
    • Group II: will have a subset telling you the hazard is gaseous in nature
      • A: methane, propane, and other similar gases
      • B: ethylene and gases that present similar hazard risk
      • C: acetylene, hydrogen or other similar hazards
    • Group III: dusts and other subsets by particle size and material type

There are also logos on the labels of gas detectors to show which association has tested and evaluated the equipment to ensure its safety based on a set of applicable standards. While safety is imperative to all certifications, customers should still want to understand what circumstances their gas detector(s) is certified to face. The IECEx logo shows that this detector is certified to IEC and ATEX standards, and the CE Mark is a universal marking for Europe similar to the UL logo in the United States. These marks indicate that the gas detector meets certain safety, health and environmental protection requirements. Underwriters Laboratories, certifiers using the UL symbol, identify many different types of electrical equipment. Other familiar markings include CSA (Canadian Standards Association) and MSHA (The U.S. Mine Safety and Health Administration). 

A device marked with the CSA logo and a marking that it has been certified to standard 22.2 No.152 indicates that the part of a device that detects combustible gas is up to Canada’s performance standards required for a combustible gas detector. Similarly, the MSHA logo and a label stating that it is a permissible methane detector indicates the device has been certified to United States performance and safety specifications established for methane detectors.

DOD Technologies offers enhanced systems and continuous monitoring solutions, making us the leader in gas detection for a variety of applications. With over 150 years of combined instrumentation and application expertise, our solutions meet the most stringent requirements to help keep your employees, operations and public health safe.

Contact DOD Technologies today at (815) 788-5200 or through our online form for more information regarding the solutions we offer as well as helping you find specific certification devices.