“Explosion Proof”: Its Not Just a Label|
Hazardous work areas are one of the most demanding environments for the workers and equipment that must operate within them. The often confined spaces combined with the presence of volatile materials presents a serious danger of fires and explosions that must be adequately addressed to insure the safety of workers and the public in both the work space and the surrounding area. One of the biggest areas of concern is the control of possible ignition sources that can inadvertently lead to the ignition of volatile materials contained within the workspace that can result in explosions and fires. Confined spaces that may contain volatile atmospheres include the storage tanks of ships, agricultural silos, commercial spray paint booths, laboratories, industrial complexes, underground fuel storage tanks, and just about any location where volatile chemicals and vapors as well as fine dust particles may be present either intermittently or on a regular basis. Equipment to be used in such locations must be explosion proof rated and carry the correct classifications.
Despite a longstanding industrial and commercial understanding of the dangers present when working around volatile materials, there have been numerous accidents that periodically underscore those dangers and the need for effective safety measures to prevent them. Explosions in coal mines and at water treatment plants, fires and explosions in grain silos, and incidents involving privately operated paint booths have occurred with some regularity and demonstrate the serious problems created by failures in both the equipment used and operator procedures. Because of these dangers and the history of accidents created by them, several organizations have been formed to develop both procedures and regulations designed to mitigate the dangers posed by working within hazardous locations. Of these organizations and regulations, OSHA and the National Electrical Code or (NEC) are the most notable. The National Electrical Code (NEC) defines hazardous locations as those areas "where fire or explosion hazards may exist due to flammable gases or vapors, flammable liquids, combustible dust, or ignitable fibers or flyings." Each location has its own particular characteristics and level of potential danger, thus the NEC has set classifications and recommendations based on the properties of each.
OSHA is the federal agency charged with enforcing health and safety laws and regulations and any work that is to be performed in hazardous locations must conform to the rules and regulation specified under the relevant OSHA guidelines. Failure to comply with these regulations not only exposes the workers within hazardous locations to excessive danger but also the companies responsible to possible litigation in the form of fines and penalties. Because of the consequences posed by both the possibility of injurious accidents and financial losses through litigation, it is imperative that the OSHA guidelines relevant to a particular work area be followed and the correct equipment be used. Employers and individuals interested in further information regarding the rules and regulations surrounding hazardous location workplaces should visit OSHA’s website at OSHA.gov to familiarize themselves with the classifications and requirements related to their particular situations.
Further consideration must be given to the equipment to be used in hazardous locations. Such equipment must meet certain guidelines for a given location and be in compliance with OSHA recommendations. Equipment is approved and rated for a given application according to standards and evaluations set forth and performed by organizations such as Underwriters Laboratories and will carry these approvals and ratings with their accompanying literature and on the equipment itself. It is the responsibility of the business or individual to ensure that all equipment used in hazardous locations is approved for their particular job’s classification and the U.L. ratings are included to assist in making these determinations and verifying a particular piece of equipments suitability. For more information on how Underwriters Laboratories performs its evaluations and assigns ratings visit their website at UL.com.
Equipment intended for use in hazardous locations should be chosen according to its ratings and the location it is going to be used in. It is important to recognize that just because a particular piece of equipment is rated as explosion proof does not mean that it is suitable for all hazardous locations. As mentioned earlier, different locations present varying levels of hazard depending upon the nature of the volatile materials that are present and the equipment chosen must be rated for use in that particular location. An explosion proof light like the Larson Electronics Explosion Proof 26 Watt Fluorescent Handheld Light is approved by U.L. for Class 1 Division 1 use. What this means, is that this lamp has been rated by U.L. for use in environments that contain volatile vapors or liquids in flammable or explosive mixtures which may be constantly present. In order for a lamp to be suitable and in compliance with OSHA regulations, it must carry these types of classification.
There are many pieces of lighting equipment on the market today that are listed as “vapor proof” or “sealed”. Although this may be true, this does not mean they are suitable for use in hazardous locations. Without the required approval and classification ratings as provided by a certified evaluating group like U.L., these lamps are not in compliance with OSHA regulations and their use in hazardous locations is not approved. These units are not capable of preventing inadvertent ignition of volatile materials and are not capable of containing ignitions within themselves as true explosion proof equipment is. It is important when selecting explosion proof equipment, that only equipment that carries certified ratings be considered.
The importance of ratings and the proper selection of equipment based on those ratings cannot be overemphasized. Many of the commercial or industrial accidents that occur have been a result not of equipment failures, but of improperly chosen and used of equipment. In 2006, The North Carolina Department of Labor fined a Morganton chemical company $379,050 for violations that led to an explosion which caused fatalities. Part of the department’s findings included the unsafe use of electrical equipment near flammable liquids. In 1999, the Transportation Safety Board of Canada found that the explosion and fire aboard a petroleum tanker was caused in part by the use of improper electrical equipment which ignited vapors in the vessel’s tanks. The equipment noted was not approved for use in hazardous environments and the resulting fire destroyed both the vessel and the wharf where it was docked.
As can be seen by the above examples, when considering any equipment for use in locations that may present a fire or explosion hazard due to the presence of volatiles chemicals or substances, it is imperative that the equipment be rated and classed by an approved agency. It is the responsibility of these agencies to ensure that equipment is properly rated and classified. It is the responsibility of the companies, contractors, and workers involved to choose and properly use equipment approved for their specific conditions. Failure to comply can be not only expensive, but fatal.