Confined Space Lighting for Hazardous Locations |
Confined spaces represent some of the most dangerous work places in commercial industries. Because of their enclosed nature, confined spaces are poorly ventilated and allow volatile gases, fumes, vapors and particulates to accumulate and increase in atmospheric density to potentially explosive levels. Confined spaces represent a hazardous work area and are loosely defined by a few general characteristics.
- The area is large enough to permit entry and the performance or work;
- Has limited openings for entry and exit; and
- Is not intended for continuous worker presence within the space.
Examples of confined spaces are the chemical storage tanks used by power plants and industrial operations, silos used in agriculture, ship tanks used for the transport of chemicals, petroleum and other volatile materials and railroad car tanks. Each of these is an example of confined spaces that represent hazardous conditions for workers who must enter them to perform jobs such as servicing and cleaning.
Although there are many procedures and programs in place to mitigate the dangers of working in confined spaces, accidents still occur and it is critical that workers entering confined spaces be aware of the hazards at all times. Most states have implemented programs and regulations intended to create and enforce standards governing the performance of work in the hazardous conditions that confined spaces represent. These regulations have been largely successful in reducing the number of incidents resulting in injuries, damages and deaths in hazardous work areas. These programs and regulations center on educating the workers, providing rules for the types of equipment to be used and how work in confined spaces is to be performed. In order to ensure the maximum safety of all workers, these regulations must always be observed and adhered to. This can be a problem as these hazardous areas often vary in the level of danger they present.
Confined spaces can often appear non hazardous, but this appearance is deceiving. Workers may have entered and exited, performed work and tested for the presence of volatile compounds previously and found conditions acceptable, yet conditions within these spaces are highly dynamic and as a result can change quickly and without notice. Because of this, any time workers are about to enter a potentially hazardous confined space, testing for the presence of volatile compounds and their levels should precede entry. The proper gear must always be used and the procedures for removing the presence of volatile compounds from the work space must always be implemented if there is any doubt.
Although due diligence and procedure can greatly reduce the hazards of working in a confined space, there are no guarantees that they will be one hundred percent effective in protecting the worker. As a result, further measures must also be taken to ensure that the risks from explosions and fire are reduced as much as possible. These measures include ensuring that workers have the properly rated equipment for the jobs at hand and that this equipment is properly used and maintained. According to studies and reports compiled by OSHA, most workplace accidents are a result of human errors and the improper use of equipment. For example, something as simple as a naked light bulb in a non explosion proof housing can instantly ignite volatile vapors or gases if the light is dropped or the bulb broken and result in a serious explosion or fire. Fire and explosions are two of the biggest concerns with working in confined spaces due to the unpredictable nature of volatile gases or vapors within an enclosed area. For work that is to be performed in a confined area where gases or vapors may be present, any equipment used by the workers must be explosion proof and rated for use in that particular environment.
Lighting the interior of confined area workspaces is almost always a necessary requirement and any lighting equipment used must be rated explosion proof by a recognized authority such as Underwriters Laboratories. Portable lighting, personal work lights and commercial tank lights all must meet with OSHA guidelines for use in hazardous locations when used in confined work spaces where volatile compounds may be present. Lamps like Larson Electronics’s Explosion Proof Light - Class 1 & II Div 1 & 2 - 70 Watt Metal Halide are specifically designed to meet the requirements set forth by regulatory agencies for explosion proof lighting and are appropriate for use in locations like confined spaces where volatile compounds may be present.
Lights like these reduce the chances of accidentally igniting volatile compounds by preventing heated gases from escaping the lamps housing until they are cooled enough to be incapable of causing ignition and are constructed of materials that resist producing sparks when they are dropped or make contact with other metallic surfaces. These lamps allow workers to safely and powerfully illuminate the interior of confined spaces while complying with the necessary regulations governing such applications. Since it is nearly impossible to guarantee that a confined space will remain entirely free of volatile compounds while work is being performed, explosion proof lights add further protection by removing possible sources of ignition. Since an atmosphere requires three basic ingredients to become flammable; fuel, oxygen, ignition source; explosion proof lights remove one of the necessary components. Although two may be present, without the third, ignition cannot take place.
Explosion proof lighting equipment must be operated only within its rated classes and divisions. A Class 2 Division 2 lamp will not be suitable for use in a location that requires a Class1 explosion proof lamp and will fail to meet OSHA requirements. Although equipment may be rated explosion proof and properly rated for a given application, it must also be used and maintained properly. Lighting equipment should always be inspected prior to use for damaged cords, loose housings, worn plugs, cracked or loose lenses and exposed wiring. Plugs that are not rated explosion proof must be connected to a power source outside the hazardous workspace.
There are many factors that affect how hazardous a confined space may be. Atmospheric conditions are only one factor, yet represent one of the most important factors that must be evaluated before workers enter. Conditions can change quickly in hazardous confined workspaces and the appropriate procedures and equipment must always be followed and used to avoid potential problems should conditions change. Explosion proof lighting adds an extra degree of protection that procedure and training alone cannot provide and should always be used in any situation that may expose workers to a volatile environment.