Any fabric that's safe to iron on a cotton setting is safe enough to run through a laser printer. Art quilters do it all the time, as do T-shirt manufacturers. It's the adhesive and the chemicals on pretreated ink jet labels that are the melt/fire risk due to the printer heat. Do not use Bubble Jet Set or Commercial Ink Jet labels in a laser printer.
Freezer paper is also safe to run through a laser printer as the stabilizer for your fabric. Dunster is correct, delay the first wash for at least a week after printing to let it cure. More about how to laser print on fabric:
http://www.brighthub.com/computing/h...les/58811.aspx
There are also several very good prior threads about laser printing labels and photos on fabric. Just put "laser printer" in the search box and you should be able to find them.