First officer reported a passengers' cell phone became lost in cabin on inbound flight creating a po...

Narrative:

We arrived at the aircraft and were informed that on the inbound segment a passenger had lost a cellphone and it was behind a panel in the cabin. Maintenance in ZZZ was planning to defer this and send us back to the mainland with the phone lodged in whatever location it was in. After a brief discussion the captain and I both felt this was unacceptable due to the risks posed for a li-ion battery fire. We could not ensure the phone and battery would be safe from damage where it was and if it caught fire might be impossible to extinguish or retrieve to put in the fire bag as provided. All of this was magnified by the fact that we'd be close to 3 hours from any suitable airport should this occur at the critical point. We insisted the phone be located and retrieved before departing on the ETOPS segment. To me it seemed counter intuitive to having all this training on portable electronic device (ped) fires; providing us with gloves and bags to store devices should they catch fire; but insisting that we launch across the water with no nearby diversion alternates with a ped that could not be retrieved or dealt with should the worst case occur. Maintenance ultimately found the phone and we departed.

Original NASA ASRS Text

Title: First Officer reported a passengers' cell phone became lost in cabin on inbound flight creating a potential fire hazard. Maintenance ultimately retrieved prior to departure.

Narrative: We arrived at the aircraft and were informed that on the inbound segment a passenger had lost a cellphone and it was behind a panel in the cabin. Maintenance in ZZZ was planning to defer this and send us back to the mainland with the phone lodged in whatever location it was in. After a brief discussion the Captain and I both felt this was unacceptable due to the risks posed for a Li-ion battery fire. We could not ensure the phone and battery would be safe from damage where it was and if it caught fire might be impossible to extinguish or retrieve to put in the fire bag as provided. All of this was magnified by the fact that we'd be close to 3 hours from any suitable airport should this occur at the critical point. We insisted the phone be located and retrieved before departing on the ETOPS segment. To me it seemed counter intuitive to having all this training on Portable Electronic Device (PED) fires; providing us with gloves and bags to store devices should they catch fire; but insisting that we launch across the water with no nearby diversion alternates with a PED that could not be retrieved or dealt with should the worst case occur. Maintenance ultimately found the phone and we departed.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1575381
Time
Date	201809
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	Boeing Company Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Parked
Flight Plan	IFR
Person 1
Function	First Officer
Experience	Flight Crew Total 8431 Flight Crew Type 2569
Events
Anomaly	Deviation - Procedural Hazardous Material Violation Deviation - Procedural Published Material / Policy

First officer reported a passengers' cell phone became lost in cabin on inbound flight creating a potential fire hazard. Maintenance ultimately retrieved prior to departure.