HOW TO CHOOSE A FLASHLIGHT FOR USE IN HAZARDOUS LOCATIONS
By Scott Jones, Director of Lighting Product Management at Pelican Products
Anyone who works in locations where accidental fire or explosion are safety concerns knows that all equipment used in such locations must be tested and approved as safe to operate. Flashlights fall under this category, as they are potential sources of ignition.
Flashlights contain an energy source (battery) and possess the ability to create heat. These need to be contained in a safe manner before one can introduce them into a hazardous environment. The introduction of air and a flammable material to a heat source could cause a fire or explosion, so flashlights intended for use in hazardous environments must be specially designed to greatly reduce the potential of ignition.
Hazardous locations are defined by the presence of flammable gases, vapors or liquids, combustible dusts or ignitable fibers or flyings that pose a risk of fire or explosion. Articles 500 through 506 of the National Electric Code (NEC), a publication of the National Fire Protection Association (NFPA), classify hazardous locations by the properties of the hazardous materials and the likelihood of flammable concentrations being present. They also stipulate safety requirements for all equipment being used in these areas.
If you’re looking for a flashlight to use in a hazardous location, then you need to understand the nature of the ignition risk in that location so you can choose the appropriate model. You should familiarize yourself with these guidelines in order to ensure that the selected flashlight carries the safety certifications that match the environment in which it is to be used.
In North America, the NEC classifies hazardous locations by four criteria: Class, Division, Group and Ignition Temperature.
Class defines the nature of the potentially hazardous materials present at the location. There are three Classes:
- Class I: Flammable Gases, Vapors or Liquids (e.g. gasoline)
Locations where you would typically encounter Class I materials include oil refineries, offshore oil rigs, paint warehouses and spray booths.
- Class II: Combustible Dusts (e.g. metallic dusts, flour and cornstarch)
Class II materials are typically found in locations such as coal mines, munitions factories, grain silos and hay storage facilities.
- Class III: Ignitable Fibers and Flyings (e.g. rayon, nylon, cotton, sawdust and wood chips)
You could expect to find Class III materials in locations such as paper mills, woodworking facilities, textile mills and cotton gins.
Division describes the likelihood that there will be sufficient concentrations of hazardous material at the location to present a fire or explosion risk. There are only two divisions:
- Division 1: An ignitable concentration of the hazardous material is present under normal operating conditions.
The shorthand description for Division 1 is “hazard likely.” An example of a Division 1 location is the interior of an oil or gas tank.
- Division 2: An ignitable concentration of the hazardous material is present only under abnormal operating conditions.
The shorthand description for this Division is “hazard not likely.” An example of a Division 2 location is the area around a fuel tank.
Group classifies hazardous materials within a Class by the similarity of their properties, especially their ignition-related properties. While Class categorizes materials by their physical characteristics, Group categorizes them by their flammable or explosive characteristics.
There are seven different groups, and each one falls under the umbrella of a specific Class.
Class I Groups:
- Group A (example materials: acetylene)
- Group B (example materials: butadiene, ethylene oxide and hydrogen)
- Group C (example materials: carbon monoxide, ethyl sulfide and hydrogen sulfide)
- Group D (example materials: acetone, ammonia, gasoline and ethanol)
Class II Groups:
- Group E (example materials: combustible metal dusts such as aluminum and magnesium)
- Group F (example materials: carbonaceous dusts such as coal, charcoal and coke)
- Group G (example materials: dusts not included in Groups E and F, such as wood, plastics, flour, starch and chemical dusts)
Class III materials are not subdivided into Groups.
The maximum surface temperature of any equipment that will be used in a hazardous location must be below the minimum ignition temperature of all hazardous materials present at that location. Since ignition temperatures vary, it is important to verify that the temperature rating is appropriate for hazardous material that is present.
The Temperature rating indicates the maximum allowable surface temperature of the equipment being used during operation and is divided into six ratings:
- T1: 450°C
- T2: 300°C
- T3: 200°C
- T4: 135°C
- T5: 100°C
- T6: 85°C
When choosing a flashlight, ensure that its maximum surface temperature is less than the ignition temperature of all hazardous materials present in your work area.
THE ZONE SYSTEM
While most places in North America use Divisions to classify hazardous locations, you should be aware that most countries outside North America use a different system called the Zone system. Zones differ from Divisions in that they categorize locations based on how often (frequency and duration) hazardous materials are present.
The Zone system also classifies hazardous materials into Groups, but there are some superficial differences between Zone system Groups and NEC Groups.
We won’t go into great detail about the Zone system, but it’s something you should know about. Its classifications overlap relatively neatly with NEC classifications, and the NEC recognizes the Zone system and allows the use of Zone-certified equipment in Division-classified areas on a limited basis. This may include a flashlight you’re considering purchasing.