Can lithium batteries be used in a intrinsically safe circuit? Would a current limiting device be needed?

Lithium batteries can be used in intrinsically safe circuits in some cases. A current limiting device may or may not be necessary depending on the device. The battery itself is usually not rated as being intrinsically safe but is tested as part of the entire device. One example where a RAYOVAC® 9-volt lithium battery is being used in an intrinsically safe device is a Personal Alert Safety System (PASS) carried by firefighters, sometimes called a "fireman down alarm."