If the coating is actively flaking or paint is peeling anywhere inside the oven cavity (including under the turntable) discontinue the use of the Microwave and replace it.
It is not safe to use a microwave that has peeling paint inside of it as it presents a risk for fire, as well as health risks because the fumes and paint flakes can contaminate your food. In this situation, it's best to throw out your microwave and get a new one.
Rust being in a microwave won't do any harm unless you scrape it all off and manage to eat enough.
Smoke, sparks, and burning odor are the primary signs that signal the last days of a microwave. Other problems like unexplained loud noise, prolonged or faster cooking, loose door hinge, and malfunctioning keypad are signs to invest in a new microwave.
If the rusting is severe or widespread, it might be time to consider replacing the microwave. Rust inside a microwave can pose potential risks, as it can lead to arcing (sparking) during use.
A damaged microwave oven may present a risk of microwave energy leaks. Contact your microwave's manufacturer for assistance if your microwave oven has damage to its door hinges, latches, or seals, or if the door does not open or close properly.
Rust-Oleum 7778830 High Heat Enamel Spray Paint
The paints made for the inside of a microwave oven are usually enamel. Rust-Oleum High Heat is an enamel paint.
On average, microwaves last 7-8 years.
About the only thing you can do is clean the rust and then sand it down so that there is no rust or paint left. Then use some microwave cavity paint and spray over the area to re-paint the sanded down area.
If your microwave leaks, the fluorescent tube will glow, or the neon bulb will become noticeably brighter. Electronic testers react in different ways, so check the manual. If the tester displays a measurement, anything about 5 mW/cm2 at a distance of 5 cm (2 inches) is cause for concern.
Haier - Microwave Interior Paint Peeling
Peeling paint can be caused by frequently heating items which produce high amounts of steam.
This could lead to undercooked food, which can result in foodborne illnesses and bacteria that can lead to food poisoning. Potential for microwave radiation leaks: In extreme cases, rust can damage the door seal, leading to microwave radiation leaks.
The average microwave oven lasts about seven years with normal use, yet even less with heavy use and poor maintenance. A large family may find themselves replacing their appliance every four to five years as they become more reliant on its use to heat snacks and leftovers or to defrost meals.
Use microwaves to reheat food instead of using a regular oven. Always keep them clean so they don't rust—this means wiping down the walls, door, and floor regularly with hot water mixed with vinegar!
However, having a broken plate does not need to be a big problem. As Mark suggests, you can still use your microwave before rushing to replace it. It is just wise to replace it after some time – to avoid overcooked food.
If the coating is actively flaking or paint is peeling anywhere inside the oven cavity (including under the turntable) discontinue the use of the Microwave and replace it.
Rust inside a microwave can also impact its functionality, meaning it doesn't heat food evenly and, in some cases, may even damage electrical components, leading to safety issues or the appliance's breakdown.
You can find Microwave safe paint in most appliance stores; you just need to make sure the store provides the right kind that is microwave safe, because some paints may contain materials or particles that will react to microwaves or may release toxins that would contaminate the food in the oven.
Take Your Microwave to an Electronic Waste Recycling Center
If your local recycling center doesn't accept appliances, you can check with an environmental conservation group such as GreenCitizen, which accepts mail-ins. Send your microwave to them and they will recycle it for you for a small fee.
JENOLITE Enamel Paint and Repair Kit | 20ml | Scratch Repair | Touch Up Paint For Kitchen Appliances, Bathroom Sink, Bathtub, Shower Tray, Microwave, Fridge, Radiator, Metal.