Cast Iron Skillet vs. Glass Baking Dish

Both cast iron and borosilicate glass bakeware are rated 'best' for safety because neither uses any synthetic coating. Borosilicate glass is chemically inert — it does not leach any metals or chemicals into food at any oven temperature. It is non-reactive with acids, fats, and proteins, making it ideal for casseroles, lasagnas, and acidic dishes. The main concern with glass bakeware is thermal shock (cracking from sudden temperature changes), not chemical safety.

Cast iron is equally coating-free and adds only trace dietary iron to food. It excels at high-heat applications and retains heat longer than glass, making it better for searing, frittatas, cornbread, and dishes that benefit from a browned crust. Unlike glass, cast iron can go directly from oven to stovetop.

For pure safety, both are in the same top tier. The choice comes down to cooking application: glass is best for long, moist bakes at moderate temperatures where its non-reactivity with acidic foods is an advantage. Cast iron is better for high-heat and stovetop-to-oven cooking. If you want one pan for all oven work, cast iron is more versatile. If you primarily make casseroles and baked pasta dishes, glass is equally safe and easier to monitor through its transparent walls. Either is an excellent low-tox choice.