Microwave ovens: what the FDA's radiation standard and the 2026 standby-power limit mean for buyers

Microwave ovens are regulated as radiation-emitting electronic products. The U.S. Food and Drug Administration (FDA) has regulated their manufacture since 1971, and makers must certify that each model meets its radiation safety standard. A separate Department of Energy (DOE) efficiency rule caps the power an oven may draw in standby, with tighter limits for ovens made from June 22, 2026. Here is what those rules require, what to check on a new or older oven, and where the real risks lie.

What the FDA's standard requires

The federal performance standard, 21 CFR 1030.10, applies to microwave ovens made after October 6, 1971. Its core requirements concern leakage and the door.

The FDA describes the 5-milliwatt figure as a lifetime limit measured at about 2 inches from the oven surface, and says that limit is far below any level known to harm people. The energy also drops off steeply with distance: 20 inches from an oven, a reading would be about a hundredth of what it is at 2 inches. The agency tests microwave ovens in its own laboratory, and it evaluates the radiation testing and quality control that makers carry out at their factories.

The labels, and what they tell you

Every oven must carry a label stating that it meets the safety standard, and a permanently attached warning label headed “Precautions For Safe Use To Avoid Possible Exposure To Excessive Microwave Energy”. The standard spells out its warnings: do not operate the oven with an object caught in the door, with a door that does not close properly, or with a damaged door, hinge, latch or sealing surface. The FDA can exempt a model from some of these statements if its maker shows the oven would still meet the limits under the conditions the label warns against.

A separate rule, 21 CFR 1010.3, requires every electronic product covered by one of these FDA standards, microwave ovens included, to carry a permanent label with the maker's name and address and the place and month and year of manufacture. On a used oven, or a model that has sat in a store, that date tells you its age and which DOE standby limit it was built to.

Checking a new or older oven

The FDA says there is little cause for concern about microwaves leaking from an oven unless the door hinges, latch or seals are damaged. Its advice:

• Look at the oven carefully, and do not use it if the door does not close firmly or is bent, warped or otherwise damaged. If the hinges, latches or seals are damaged, contact the maker.
• Stop using an oven straight away if it keeps operating with the door open. The FDA has received reports of ovens that appear to do this.
• Use microwave-safe cookware, and follow the manual on containers. Some plastic containers can be melted by the heat of the food, and metal pans and aluminum foil should generally not be used, because they reflect microwaves.
• Some ovens should not be run empty, so check the manual.
• As an added precaution, do not stand directly against a running oven for long periods, and do not let children do so.
• Clean the inside, the edge of the cavity and the door with water and a mild detergent. No special cleaner is needed, and the FDA says not to use scouring pads, steel wool or other abrasives.

If you suspect a radiation safety problem, the FDA says you can contact the oven's maker, or report it to the FDA on its Accidental Radiation Occurrence Report form. Makers that find a defect, or a failure to comply with the federal standard, must notify the FDA immediately.

The bigger risk is heat

The FDA says most injuries related to microwave ovens are heat burns from hot containers, overheated foods or exploding liquids, not radiation. One hazard is superheated water: water heated by itself in a clean cup can go past its boiling temperature without appearing to boil, and a slight disturbance, such as picking up the cup or pouring in a spoonful of instant coffee, can make it erupt. Adding instant coffee or sugar before heating greatly reduces the risk, the FDA says, and you should not exceed the heating times the manual recommends.

On pacemakers, the FDA says the old concern about interference has largely been resolved, because pacemakers today are built to shield against that kind of interference. People with pacemakers who are concerned should ask their physician.

Standby power: the 2026 limit

When it is not cooking, a microwave oven still draws standby power, and DOE's energy conservation standard sets a ceiling on it. The ceiling dropped for ovens made on or after June 22, 2026.

The sums are small either way: at the old 2.2-watt limit, a built-in convection model left in standby all year would use about 19.3 kWh, or about $3.50 at the same price. Cooking draws far more power. At full rated power, an hour in a 1,100-watt microwave costs about 20 cents at the August 2026 average, as our guide to kitchen appliance recalls and running costs shows, and that guide also explains how to check a model for recalls.

Electricity prices vary widely by state, so use your own rate from your bill. The U.S. Energy Information Administration's August 2026 figures, published on October 23, are preliminary.