Actually I usually carry it in my jacket pocket or use it on the bus or outside when working..Doubt it would explode though it doesn't even get warm..

Can also use it to charge bike lights...

Also it can be run over by a car and the casing won't break

 I have no idea if it's safe...but I carry my phone in my pocket all the time and it's a Samsung

Need a mini fire extinguisher to put in a bottle cage..