"Dishwasher safe" on a food-grade item is a claim about chemical and structural stability under repeated high-heat, high-alkalinity cycles — not simply that the item won't melt. Grade 304 stainless steel can withstand dishwasher temperatures up to 170°F (77°C) and resists alkaline detergents well which is why it holds up where lesser alloys fail. The governing framework sits with two bodies: in the US, the FDA regulates food-contact materials under the Food Code and 21 CFR 177.2600, requiring that materials do not leach harmful substances; NSF International's standard NSF/ANSI 51 applies specifically to food equipment materials, ensuring they are safe for direct food contact. In the UK and Europe, food-grade materials must comply with Regulation (EC) No 1935/2004, which governs materials intended for food contact and requires migration testing to verify that no harmful substances transfer. For 304 stainless steel, dishwasher safety is a consequence of the alloy's passive oxide layer remaining intact through detergent and thermal stress — the same property that makes it inert in use.