Manufacturing, oil and gas, transportation, utilities, and pharmaceuticals manufacturing facilities are generally most at risk for exposure to flammable gasses and vapors. However, many industrial facilities have at least one or two zones within their work environment that could be classified as a hazardous location. For these zones, rugged or intrinsically safe tablets (hazardous locations tablets) and mobility devices prevent costly accidents, fires, and worker injuries.
Intrinsically safe tablets designed specifically for these environments keep workers safe and operations within compliance for national and local safety codes. These and other mobility devices are classified by the environments for which they are suitable. Choosing the right tablets and mobility devices is critical to ensure safety, efficiency, and lower cost of ownership.
While the goal of this post is to help you understand the difference between C1D1 and C1D2 certified devices, it’s helpful to start with a general understanding of hazardous environment classifications. This will inform your process as you assemble your fleet of rugged and intrinsically safe tablets.
What are Hazardous Environment Classifications?
In the U.S., hazardous locations are classified based on the National Fire Protection Association (NFPA) 70, National Electrical Code (NEC). Defined by Classes, Divisions, and Groups*, these location classifications inform the level of safety precautions required. Using the proper device ensures compliance with the Occupational Health and Safety Administration’s (OSHA) guidelines and protects your asset investments.
- Class – The type of explosive or ignitable substances in the atmosphere
- Class I – Flammable gasses or vapors
- Class II – Combustible dust
- Class III – Easily ignitable fibers or flyings
- Division – Conditions under which hazardous substances are present
- Division I – Ignitable concentrations exist under normal operation, or there is frequent repair, maintenance, or equipment failure causing additional hazards
- Division II – Ignitable concentrations exist under abnormal operating conditions
- Groups – This is based on the physical properties of the hazardous substance present, and how easily it can be ignited.
Hydrogen, butadiene, ethylene oxide, propylene oxide and acrolein
Ethylene, cyclopropane and ethyl ether
Acetone, ammonia, benzene, butane, ethanol, gasoline, hexane, methane, methanol, methane, naphtha, natural gas, propane and toluene
Combustible metal dusts: aluminum, commercial alloys and magnesium
Combustible carbonaceous dusts: carbon black, charcoal, coal and coke dusts
Other combustible dusts: Chemicals, flour, grain, plastic and wood
*While OSHA does not have specific safety requirements based on group, marking requirements mandate that equipment includes the hazardous group in which it is approved to operate.
Tablets Used in C1D1 Vs. C1D2 Environments
Intrinsically Safe Tablets Used in C1D1 Zones
Because C1D1 environments have a greater risk of fire and explosion, they require intrinsically safe tablet options. Tablets certified as intrinsically safe are designed to be incapable of causing ignition. Due to their specifications, intrinsically safe tablet options are somewhat limited.
- Intrinsic safety is a low-energy technique where the current, voltage, and power are reduced to a level too low to cause ignition.
- Batteries are designed with safety features to minimize the risk of sparks or overheating. This might include intrinsically safe barriers or encapsulation.
- Battery energy stored and the heat generated are limited in case of an internal fault.
- Operating temperatures will not exceed 135 degrees celsius.
- Tablets have no I/O, and are powered by a magnetic pin connector.
- Power and peripherals cannot be attached to tablets when in use in hazardous areas.
C1D2 Certified Rugged Tablets
Options for C1D2 certified tablets are generally more expansive, due to the fact that these devices rely on external measures to prevent ignition. Rugged tablets designed for these environments prevent ignition through housing and electrical component protection.
- Circuits are incapable of igniting flammable gas, air, or vapor through an arc or thermal effect produced under the intended operating conditions of the equipment.
- The contact mechanism for the component is designed to be incapable of igniting the specified flammable gas–air or vapor–air mixture.
- Under normal operating conditions, the electrical circuitry will not cause ignition of a specified flammable gas–air or vapor–air mixture due to arcing or thermal means.
- Must not have normally arcing parts or thermal effects capable of ignition.
Finding the Right Tablets for Your Environment
One facility may have several types of safety zones or varying operating conditions, making ensuring safe mobility devices in hazardous environments a complicated but crucial process. Having the right tablet for every zone in your facility keeps workers safe, improves compliance with local and national safety codes, and reduces TCO by minimizing downtime, repairs, and replacement.
Enlist the help of an expert to determine which locations require which type of tablet. Rugged tablet experts can help make sure you have the right intrinsically safe rugged device for your hazardous environment, giving you the protection you need to operate more efficiently while keeping your workers and your assets safe.