Glass cooktops don't impose problems because of PTFEs, but from the danger of heated cooking areas not apparent to birds. Ovens are a different story, however, it is relatively easy to check on an appliance because virtually all manufacturers maintain a relatively good customer service department. Copy down the manufacturer, model number and serial number...usually on the top or top left edge of the oven door or door frame.
When you inquire (via e-mail so you have a written record) ask if PTFEs or PFOAs were used in the manufacture of the appliance.
If you have a self-cleaning oven, you want to take all birds out of the house before using the self-clean feature and for at least 24 hours after it has finished its cleaning cycle...and be sure to use your kitchen's exhaust fan, unless it vents into the kitchen, in which case you will need to use a box fan and vent the fumes to the outside.....using the self-cleaning function will kill birds in the house.
Akraya's right, though the tops are specially tempered sheets of glass, as well as anodized metals and the new ceramic coatings.....
