Hazardous Areas are typically found in large facilities like oil and offshore oil & gas platforms, oil refineries, chemical processing plants, tank farms, supertankers, other ships that carry petrochemical cargo and even places like grain silos, which have the risk of explosion or fire due to explosive mixtures of vapors or dusts. Hazardous Areas are also referred to as "Classified Locations" in North America.
This article is a short guide to how these areas can be made safer, without any increase in costs.
How are areas classified?
Hazardous Areas in a typical facility are classified on two aspects. One is the probability of a flammable, or explosive mixture (this includes dusts too), being present in that area and secondly, the type of the material being present. Hence classification entails specifying the area (known as Area Classification) as well as the material (Material Classification). A third parameter, temperature is also important and Temperature classification, is also done. An equipment then, carries a marking that shows the Area, Material and Temperature classification, for which it can be installed safely, i.e. without the risk of explosion hazard.
Area Classification is not a permanent thing
Most area classification studies, are done during the design stage. This is not always followed up with periodic audits of whether the previous area classification still holds good or not (say due to plant modifications, change of processes, usage of different raw materials, addition of facilities and so on).
Sometimes, the basis of the area classification itself, is not understood by the people who actually operate the plant, resulting in the original design being no longer valid. This is not a one-off possibility, it happens many times. Unfortunately it may also result in a disaster.
Actual Case Study
The US Chemical Safety Board recently posted a few videos of investigations regarding actual disasters related to chemical plants on its own website, as well as YouTube. One of these videos relates to the explosion at a paint & ink manufacturing facility at Danversport, Massachusetts. If you watch the video, posted below, you will realize that the root cause of the accident, seems to be inadequate ventilation. Apparently, the original design engineers had built in the forced ventilation to reduce the area classification from say Division 1 to Division 2 or possibly from Division 2 to Safe (the latter seems more likely). This "safe area" classification will no longer hold true, if the ventilation is switched off. However, these key facts were not communicated to anybody. Of course all of this is conjecture, but perhaps you can view the video and draw your own conclusions.
How to understand the concept of hazardous area classification easily
How do you convey the concept of hazardous area classification to people working in your plant? If you refer to the published standards, the level of complexity seems to be too high to be understood by shopfloor level workers and even sometimes for practising engineers and technicians. Nobody is interested in solving some esoteric differential equations and simulations to find out if any area should be classified as Zone 1 or Zone 2. The best option is a handy guide that explains the basic concepts in a jiffy as well as shows a case study of a real life area classification. You can download it here.
Why poor area classification increases costs , reduces safety and generally is bad for the plant operation
How you classify the hazardous area in your facility is one of the most important but least understood and neglected issues today. Why? Because the way in which you classify a hazardous area can significantly affect the operating costs of your facility in the long run.
Today's competitive chemicals business environment means that all efforts are made to keep costs on a tight leash.
Globally, in area classification, there are two major standards. One is the IEC (International Electrotechnical Commission) system, which is followed in Europe, Asia , Australia, Africa and many other regions. The second system is the NEC (National Electrical Code) which is popular in North America and parts of the middle east. The IEC system has three zones (Zones 0, 1 and 2) based on decreasing probability of explosive vapor or gas mixtures being present . On the other hand the NEC system has two levels (Division 1 and Division 2), again based on decreasing probability of hazardous mixtures of gas or vapor being present.
If your facility has been designed by an engineer who has wrongly "overclassified" the hazardous areas, then you are unnecessarily incurring additional costs without any benefits. What is overclassification? Simply, it is declaring an area as hazardous when it is really not. How does this increase costs? By forcing you to buy and maintain expensive explosion protected equipment when an ordinary weatherproof one would have been just as good. Secondly, since the area is anyway not hazardous, you are paying more for safety that you do not need. It is the equivalent of wearing a safety helmet while having lunch in your home.
Declaring an area as Zone 1, when instead it should really be Zone 2 is also a case of overclassification. This then restricts your ability to use some of the cost effective techniques like "Non incendive" which are available for use in Zone 2 only (but not allowed in Zone 1).
What is worse is that if your plant has large swathes of areas marked as "hazardous", then you may have a very difficult time with your local authorities, if you approach them for permissions for expansions, etc. These days they will always display the NIMBY syndrome (Not in my backyard ). This would be really tragic, if the area does not deserve to be marked as hazardous, but it has been done by some overzealous engineer many years back.
What about underclassification? Underclassification is declaring an area as non-hazardous, which should in fact be marked as hazardous. This is possible due to ignorance or incompetence of the design engineer or perhaps the original design was modified by the owner/operators without considering reclassification. This is downright dangerous and is much more serious.
This is exactly what has happened in the case study video above.
How to resolve these problems?
How can this problem be resolved? By conducting an audit of your present facility, marking hazardous areas with reference to the current standards available, as well as training the personnel in the basics of area classification.
Everyone who works in hazardous areas, should know what is a "hazardous area". This simple logical fact is ignored by many plant managements, thinking that it is only the job of the Safety Manager. However this is not right, all personnel who actually work in a hazardous area should know what it means.
Some of the resistance of the management might be the fear that they will have to spare even more of their already shrinking pool of skilled workers for classroom training. However an effective alternative would be to impart training using modern methods such as e-learning.
Abhisam Software's ebook on Hazardous Area Classification, can be used to impart this basic training to plant personnel very easily. You can download the ebook here.
For instrument engineers, technicians and similar engineering personnel, the Hazardous Area Instrumentation is an excellent e-learning course that can make concepts crystal clear at less than the cost of a typical explosion protected instrument! Find out more here.
It is ridiculuous to teach 21st century technology with 16th (?) century teaching methods (classrooms with a teacher and a blackboard). Use e-learning instead. The interactive animations and simulations in the self learning course, making understanding very easy.
Abhisam Software's e-learning course can be used to train engineers and technicians very effectively without them having to be away from work, even for a single day. You can access this course online via any browser and also get certified. Contact us today to find out more.
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