Teams working in hazardous areas deal with elevated risk levels as they go about their work. Operating an electrical device in a hazard zone can ignite flammable material and cause potentially devastating fires. Using the right electrical equipment can help minimize your risk of explosion and fire. Keep reading to learn what intrinsic safety is and how equipment that is certified as intrinsically safe can protect your staff and your equipment from danger in a potential hazard zone.
What is the Definition of Intrinsic Safety?
Intrinsic safety refers to an approach that ensures the safe operation of equipment in a potentially hazardous zone. More specifically, it refers to the kind of electrical equipment that can operate safely in hazardous areas.
Conventional electrical appliances can cause ignition in several different ways. Sparks, or electrical arcs in motor starters and switches can ignite flammable gases, dust, or other materials. Electrical equipment can also get hot enough to ignite hazardous gasses or combustibles. And short circuits or electrical failures can also cause ignition.
This makes it risky to use electrical equipment in many environments. Even something as small as a conventional flashlight can pose a serious risk in a hazardous environment. To ensure safety and maintain productivity, your teams need the right equipment to perform maintenance, pressure calibration, and other tasks. That’s where intrinsically safe equipment comes into play.
Intrinsically safe devices are built to be ignition-proof. They won’t cause an explosion or spark a fire. They are designed to store only a very low, safe level of energy and to operate at a low temperature. This ensures that they never generate enough voltage or heat to ignite volatile gases or other flammable matter.
Understanding Classes of Hazardous Environments
Hazardous zones are areas that contain highly combustible materials, like volatile gas, fuel, or even dust. In an atmosphere that contains flammable material as well as oxygen, even a tiny spark is enough to create a dangerous explosion.
Petroleum refineries, dry cleaning plants, aircraft hangars, and other facilities where flammable gas is present are considered “Class 1” hazard locations. Using a conventional electrical device in these areas could potentially cause a catastrophic explosion.
Grain elevators, flour and feed mills, and plants that store metal-based powders are “Class 2” hazard zones. These facilities contain enough combustible dust in the air to cause serious fires in case of an igniting agent.
Textile mills, seed mills, and lumber mills are considered “Class 3” hazard zones. In these environments, fibers and flyings can collect around machinery. Contact with hot metal or with an electrical spark can ignite them into flame.
It is absolutely critical for your whole team to have proper safety training and use the appropriate equipment for the environment. Electrical equipment that is certified intrinsically safe keeps risk at a manageable level and can save lives and property. Intrinsically safe equipment is also labeled to show which class of hazard zone it can operate in.
Intrinsic Safety Devices for Class 1 Hazard Areas
Safety experts group gasses according to their ignition levels. For example, a “Group A” gas like hydrogen, for example, has a relatively low ignition level. A circuit with a combination of 30 V and 150 mA could create a powerful enough spark to ignite the hydrogen gas present in the air.
Similarly, when hydrogen is present in the area, all the electrical equipment used must not reach surface temperatures greater than 100 degrees Fahrenheit (85 degrees Celsius). Intrinsically safe devices for use in Class 1 areas must operate well below the temperature and voltage levels that could cause ignition.
What is the Difference between Explosion-Proof and Intrinsic Safety?
Intrinsically safe and explosion proof are both approaches designed to protect people and property in hazardous areas. Both approaches have advantages, and many operations need both types of equipment depending on where and how each piece of equipment will be used.
Here’s how the two designations differ. An intrinsically safe piece of equipment is incapable of causing an explosion or a fire. That’s because intrinsically safe devices operate with controlled internal temperatures and are designed with simplified circuitry to reduce power availability. They are also built to be extremely dust resistant, to prevent short circuits and to protect against contact with combustible dust.
In contrast, an explosion-proof device uses a protective enclosure to help contain explosions when they do occur. That same enclosure also protects the device in case of explosion.
Briefly, an intrinsically safe device prevents explosion; an explosion proof device contains explosions.
Many facilities choose to use both intrinsically safe and explosion proof devices. Often, facilities find that explosion proof equipment works best in permanent installations, where they need tools with high voltage and power levels. Intrinsically safe devices tend to work well with portable instrumentation.
It’s always a good idea to consult with a certified expert when choosing the right tools for your facility. Every operation is a little bit different, and it’s wise to get input from the experts before deciding on a solution.