I've flown many commercial flights with a FP/international cartridge loaded in the pocket of a starched, white dress shirt. I never had a single problem. In fact, I always keep a dozen or so cartridges loaded in my brief case. Never had a problem there either.
If you fly prop planes that travel under 10,000 feet without pressurized cabins, this could present more of a problem, but I've never had issues here either.
Now, if you leave your brief case containing unused international cartridges in your automobile at the Airport's park and fly lot, I'll promise THIS WILL BE A MAJOR PROBLEM in Georgia's summer climates!