I have melted aluminum foil on the bottom of my oven. Can I still use the oven for baking?
I doubt you have melted aluminum foil at the bottom of your oven. The melting temperature of aluminum foil is 660 degrees Celsius (1,220 degrees Fahrenheit) at standard pressure. It is possible that you have a layer of grease between some foil and your oven bottom. This combination will likely char and burn. I would clean your oven well, and use as normal.
Aluminum foil itself should be safe. In fact, before ‘self cleaning’ ovens, I knew people who lined the bottom of their oven with foil incase any spills should happen.
The only issue that might come up is if there is any sort of coating on the foil. Reynolds says their non-stick foil is safe up to 650°F, which should be higher than home ovens can get to unless it’s in direct contact with a heating element. If you’re using a different brand of coated foil, you may want to check the box or the company’s website
update: as the foil is stuck, there’s also the question of what’s sticking the foil on if it hasn’t melted. There may be some food residue that will smoke as it bakes off. Unless there’s a huge spill that’s obvious, it likely won’t be very much (and should then release the foil)