Mobile phone usage in chemical plants

I am reproducing a good discussion in a process safety forum in Linkedin (Process safety management) here:

• Mobile Phone usage in restricted area inside control building

  Shankar Bhosale

  Saudi Aramco Total Refinery and Petrochemical Company

  Presently we have Mobile phone policy of forbidden f using mobile phone inside restricted areas of our refinery . Recently our management ask us to get some detail about weather we can allow using normal mobile phone in restricted area building only ( Main control Building - Blast proof) . So we would like comment from members for possible experience in other organisation regarding implementation of such policy .

  • Wayne Betts I was asked a similar question at one place I worked. The perception was that cell phones could act as an ignition source in a flammable atmosphere. I found the following relevant report:
    http://www.exponent.com/files/Uploads/Documents/CellPhoneReport.pdf
    Also, you can find a very good explanation of minimum ignition energy (MIE) in the CCPS text "Guidelines for Determining the Probability of Ignition of a Released Flammable Mass". Although in this case it was generally agreed that cell phones present an extremely low risk as an ignition source, the company decided it was not worth the risk and upheld the rule to ban cell phone use in the plant.

    
    
• David Moore Allowing mobile phone use in a control room is not an area classification issue. Control rooms are typically located within a NEC classified area but the interior of the control room is not classified - i.e. it's unclassified. Control rooms are kept unclassified by means of a ventilation system keeping the control room environment at a pressure higher than the outside atmosphere. This pressurized system keeps outside toxic or explosive vapors from leaking into the control room. Since the control room is unclassified then any general purpose electrical device is allowed in the control room. As a matter of fact, it would be impossible to have all the electronics that are necessary to be in the control room be intrinsically safe or explosion proof. This is why control rooms are unclassified. 
  
• Karl-Fred Woerner I agree with David. One reason not to allow mobile phones in control room is potential distraction. We do not allow privat mobile phones in control rooms. Before allowing mobile phones in a blast resistant building you should also check connectivity because the steel used in the construction migth might function as a shield.


• Richard Palluzi Standard cell phones are not approved for electrically classified areas. Yet many studies have indicated that the chance of ignition is very low. Most petrochemical organizations will not allow them; I suspect more from a liability issue than a technical issue. It would be great to have an AICHE, ISA, API, ASSE, or NFPA study of the real technical risks. Sadly it's unlikely to happen as testing is very expensive and with the large number of different types doing any meaningful testing is probably problematical at best.
  In addition to the potential ignition source issues, the question of distractions always arises. Yet, at the same time, most organizations have so integrated cell phone use into their daily business that lack of access is a definite reduction in efficiency. The impossible (or at least very difficult) issue to address is how to allow normal company business while excluding needless distractions. Most organizations have some restrictions in place at least on paper.

  
  
• Luis Eduardo Pardo Diaz Greetings, there are several reasons why cell phone use in control rooms is prohibited, among the most outstanding are:
  1. distracter for operations: can you imagine an operator control panel working and talking on the phone at the same time? ¿Differentiating between sounds alarm signals and tones phone?
  Simply because of the sensitivity of the operations control room, should minimize the factors which could cause distraction operators control panel. This is the main reason for the restriction.
  2. Possibly the emission of signals or other cellular radios, instruments may alter operating wirelessly, which generate false signals and the problems that we know that these can generate.
  3. The cell phone is not a certified electronic equipment for hazardous areas and remember that by the characteristics of the control room, they can be exposed to flammable gases and vapors, and cell element could be the initiator of an explosion or fire.
  Happy day.

  
  
• Daniel Lewis In the classified area - Agreed, standard personal mobile phones are not rated and therefore present a risk of fire, even if this risk is low.
  In unrated control rooms or break rooms - There are numerous other unrated electrical devices in these rooms, so they do not create an increased ignition risk. It is a management issue to make sure employees are not using them excessively, and that they do not carry them outside into the classified area. 

  
  
• Jeremy Roland My question would by why do they want to have cell phones in those areas? Typically the floor employees have no need for a phone to conduct their tasks. Often times they will never even question these policies. Managers on the other hand seem to be unable, or unwilling to put their phones down. They often question these policies because they feel that they need to have their phone on them at all times. My question to them would be what is more important not missing an email, text, or call or not blowing themselves and everyone else up. . Even if the chances are a million to one that it could happen i would not want to risk being that one.

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