while "flammable" they are NOT combustible so no real threat..after all, fabric is flammable!

It appears I have my informational wires crossed:

Liquid fabric softener boosts the burning speed of all-cotton clothing including fleece, terry cloth and velour, according to the consumer watchdog Consumer Reports. Use dryer sheets for these clothes instead.

But 'green' folks do warn that the chemicals in dryer sheets are something to be avoided--possible skin and respiratory irritation--especially babies. Dryer sheet build-up can cause clogging of lint filters so that might be the source of my erroneous warning.

This has been a topic of discussion before: http://www.quiltingboard.com/t-93940-6.htm

and appears inconclusive.

I know the military are not allowed to use fabric softener on their uniforms..something about a phosphorous build up that makes them visible through night vision goggles...scary..

You can also use the non-woven coffee filters for foundation / paper-piecing and they have no chemicals in them.