Portable Electronic Devices in Hazardous Areas

Monday, January 13, 2020

Ph.D, REP, ASP, CSP; AECOM’s Americas Process Safety Lead

There are plenty of blog posts stating portable electronic devices (PEDs) and industrial settings don’t mix, but most are about distracted working: PED use is unsafe because employees are distracted and unfocused and accidents can happen. That’s not this post. Instead, I want to talk about the legal and safety challenges that pose liabilities when PEDs are intentionally used as part of the work environment—especially within designated hazardous environments.

Technology—The Good and the Bad

Technology of all sorts is heralded as a boon to industry and consumers in countless ways, because its’ wide-ranging use for a variety of professional and personal tasks provides efficiencies and convenience for the owner/operator and employee alike: job safety analysis performed on smart phones; inspections and reporting done on tablets; use of customary items like health trackers, smart clothes, hearing aids, personal cell phones, and digital watches.

Owners and employees often don’t realize how the use of these devices in hazardous locations may violate regulations and codes and has the potential to cause harm. Confusion around the safe use of PEDs exists due to misconceptions around electrical safety, often supported by unverified and incorrect internet accounts and interpretations. Further, strong regulations and codes may not initially make sense considering no incidents involving hazardous locations have been directly attributed to PED use.

So, how do we properly consider the use of global regulations that restrict or prevent the use of PEDs within hazardous areas? The answers become evident with a close reading of case studies and a keen eye toward safety.

It Doesn’t Have a Plug—Is it a PED? What About Augmented Reality?

PEDs are different from portable electrical equipment, which include powered electric tools like drills, flashlights, and saws. PEDs are limited to a subgroup that use solid state, integrated circuits, or components to process data.

Don’t be confused just because these devices don’t have a plug. PEDs are usually powered by batteries, which can ignite just as well.

Even in older or low-tech facilities, PEDs have been used for decades, and practitioners have had to consider the potential risks that arise from the use of non-rated electronics in hazardous areas for some time. Calculators, bar-code readers, and digital voltage meters are just a few.

In addition to the older electronic equipment and the newer use of app-filled tablets and smart phones, cutting-edge hardware that integrates augmented reality significantly expands the range of work within hazardous areas beyond customary tasks, thereby broadening safety considerations.

Table 1, below, displays examples of various personal and work-related PEDs.

Table 1: Examples of Portable Electronic Devices

PERSONAL Electronic Devices

WORK-RELATED Electronic Devices


Augmented reality goggles

Cell phones

Bar code readers

Hearing aids


Health trackers


Smart phones

Digital volt meter (DVM)/Digital multimeter (DMM)

Watches (digital)


Smart clothes


What is a Hazardous Area?

Hazardous areas are locations where flammable or combustible vapors, gases, or liquids; combustible dusts; or ignitable fibers or flyings may be present. An area is (or is not) designated as “hazardous” based on two things: the type of hazard; and the probability of the hazard being present. Sound facility design designates separate areas for different hazards, so colocation is a rarity.

Current Standards, Regulations, and Codes

Individual countries have enacted legislation regulating PED use based on national and international standards designed to protect employees and the environment. They categorize levels of risk in slightly different ways.

Each standard considers the two factors mentioned: the type of hazard and the probability of its presence. The U.S. standard uses Classes and Divisions and considers the type and probability of occurrence. The European standard uses Zones, which loosely correspond to the Class and Division designations used in the United States.

The National Fire Protection Association (NFPA) is the U.S. entity that determines how “hazardous location” is defined, and its European counterpart is the Atmospheres Explosibles (ATEX). The International Electrotechnical Commission (IEC) is an international standards organization that prepares and publishes international standards for electrical, electronic, and related technologies.

An Important Best Practice

The following tables help us to see a critical best practice: PED use in hazardous areas must be appropriately rated for each hazard. If the electrical equipment is not appropriately rated, then it should not be used in that hazardous area.

  • Table 2 summarizes many current regulations and codes in place around the world.
  • Table 3 summarizes the classification scheme used by the National Fire Protection Association (NFPA) in the National Electrical Code (NEC). Some facilities classify the hazardous area based only on the Class and Division (i.e., Class I Div 1), while other facilities may designate down to the Group level (i.e., Class I Div 1 Group B).
  • Table 4 compares the NFPA classification scheme with the ATEX and IEC schemes. This table importantly provides a means to translate between NFPA, ATEX, and IEC language.

Cell Phones, Tablets, and . . . the Internet

We’ve all heard varying accounts of how cell phones spontaneously combust. Truth be told, little research is available on PED use in hazardous locations, including at gasoline-filling operations.

When cell phones first gained popularity, makers themselves investigated the likelihood of a cell phone initiating an explosion during gasoline fueling. One prominent study concluded that the cell-phone ignition in this scenario is highly unlikely. Further, it was pointed out that more likely ignition sources are present during the normal process of refueling a vehicle.

Professional associations also conducted a series of tests that concluded that although the probability of this scenario is at most one in a million, it should not be ignored. The greatest risk was associated with the cell phone dropping on a hard surface during fueling. Recently, a NFPA technical committee further considered the safety of PEDs that are used to pay for the fuel itself, and they came to the same conclusion.

Recent internet results reveal contributors with vastly different expertise and experiences stating that cell phones have been (or have not been) the cause of industrial fires and explosions involving hazardous locations. One website essay describes an unwitting vendor entering a closed-down hazardous area with dangerous vapors. The description implies that the cell phone was the source of ignition. However, the report from the regulating safety board states there were various unprotected circuits and motors operating at the time of the incident, making the source of the ignition unclear. This example illustrates how widely read Internet accounts can depart from fact-based reports, thereby potentially influencing public and employee behavior.

So prevalent is the discussion on cell phone usage around gasoline filling stations that even fact-checking entities have conducted their own investigations, which ultimately have aligned with science-based conclusions.

Simply Put: Follow the Law and Be Safe

If you keep a clear head about the law, safety, and liability, appropriate actions for owner/operators and employees remain clear:

  • Science-based research indicates a small risk due to PED use in designated hazardous location—yes, including cell phones. The bottom line is that it is unsafe to use PEDs in a hazardous location.
  • Regulations and codes are in place and enforced in all hazardous locations.
  • Logically, there is liability involved with PED use in a hazardous environment. In order to limit liability, employees must be aware, trained, and adhere to the regulations and codes associated with hazardous locations.

Management should follow these basic principles:

  1. All electronic equipment intentionally brought into the hazardous area to perform work should be appropriately rated for the hazard.
  2. Company policy should prohibit the use of non-rated equipment within hazardous areas, unless a hot work permit is used with a detector for potential flammable atmospheres.
  3. Company policy should prohibit employees from bringing personal portable electronic devices into hazardous areas. This may necessitate training.

Follow the law and be safe—pass it on!