Aluminum foil can be used in many ovens to cover food or line a baking pan, but it must not block airflow or touch heating elements. The oven manual is the authority because some manufacturers prohibit lining the oven floor.
Use it on food or suitable pans
Covering a dish can reduce splatter or excessive browning. Leave room for airflow when the recipe needs it and keep foil from extending toward heating elements.
Do not line the oven floor unless the manual allows it
Foil placed on the oven floor can reflect heat, damage enamel, interfere with sensors, or block ventilation. Use a suitable pan on a rack to catch drips when the manufacturer permits it.
Keep foil away from heating elements
Aluminum can melt or arc in some appliances if it contacts a heating element or electrical part. Even with concealed elements, follow the manual’s placement restrictions.
Use another material for prolonged contact with acidic foods
Tomatoes, citrus, and other acidic foods can react with aluminum and cause pitting or metallic transfer. An oven-safe glass or ceramic dish avoids prolonged direct contact when that matters.