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1 June 2002

Cell phone debate

While fires and explosions within a plant are a concern, those potentially caused by portable equipment are also sparking debate among experts in the field.

A 6 March safety alert from the U.S. Department of the Interior Minerals and Management Service cited a flash fire that occurred on a platform in the Gulf of Mexico OCS region while a contract panel specialist was working on an open panel that used supply gas for the instrumentation.

The contractor was carrying a powered-up cellular phone that rang while he was working on the panel. When the employee flipped the bottom piece of the phone to answer the call, a fire erupted, causing second degree burns on the worker's forearms and face.

"Personally, I strongly doubt that the cell phone was the source of ignition, even though I would not doubt it will eventually be named as a scapegoat if nothing else can be found," said David Bishop, a professional engineer and consultant for electrical equipment in hazardous locations in Destrehan, La. Bishop's comments appeared as a rebuttal to a letter published in ISA's New Orleans section newsletter that referred to the alert. Bishop is also the managing director for ISA's SP12 committee on the same subject.

"There's no doubt the batteries in cell phones are capable of providing enough energy to ignite methane air mixtures," he said. "If batteries do separate from a phone, as in the case of the phone being dropped, an ignition-capable arc could result if the connection between the phone and the battery were broken." But in this case, Bishop said the person with the cell phone didn't report dropping it—merely flipping it open.

Bishop said it's important the industry sees quick publication of the newest SP12 recommended practice on battery operated equipment, Electronic Products Suitable for Use in Class I and II, Division 2, Class I, Zone 2, and Class III, Division 1 and 2 Hazardous (Classified) Locations. However, investigation of this incident may impede progress. "The investigation of this incident has been hampered by the fact that both of the most well-known electrical test laboratories in the U.S. have refused to test the suspect cell phone," he said. But the standard's publication is crucial, especially to the petrochemical and oil and gas production segments, he said.

"Do you wear your watch in locations where flammable gases and vapors might be present? If so, does the watch have an FM or UL or other label on it stating it has been tested and approved for such locations?" he said.

"What about hearing aids? Do we need to ban all hearing-impaired persons from chemical plants? Even worse, shall we require all persons wearing pacemakers or automatic defibrillators to leave them at the heliport onshore when they go offshore?"