# Microwave oven

> The only consumer appliance with its own federal leakage standard: 5 mW/cm² at 5 cm from the surface over the product's lifetime, which is 50,000,000 µW/m² — high compared with any communications source.

- Canonical URL: https://emfbase.com/emitters/microwave-oven
- Collection: Sources & emitters
- Record id: `emitters:microwave-oven`
- Status: verified
- Last verified: 2026-08-12
- JSON: https://emfbase.com/api/emitters/microwave-oven
- Also known as: microwave leakage

## Key values

- **Category:** radiofrequency
- **Emission bands:** 2.45 GHz ISM
- **Environments:** home, workplace
- **Transmit power:** 1,000 W EIRP — Regulatory value — legally enforceable — Cavity magnetron output is roughly 700–1200 W, contained by the cavity and door screen; the regulated quantity is leakage, not output. [fda-microwave, fcc-part18]
- **Duty cycle:** Only while cooking. Older or damaged door seals and hinges are the usual cause of elevated leakage.

## Field strength by distance

- **5 cm:** 5 × 10^7 µW/m² — Regulatory value — legally enforceable — FDA limit for leakage over the lifetime of the oven: 5 mW/cm² at 5 cm. New ovens are required to be below 1 mW/cm² at 5 cm. Well-maintained ovens typically measure far below both. [fda-1030-10, fda-microwave]
- **1 m:** 125,000 µW/m² — Computed estimate — Inverse-square scaling of the 5 cm FDA leakage limit to 1 m (factor of 400). — Upper bound implied by the leakage limit, not a typical measurement. [fda-1030-10, itu-fs-relations]

## Mitigations, most effective first

- **Stand back a metre or more while the oven runs rather than watching through the door.** — Leakage falls with the square of distance, and the limit is defined at only 5 cm.
- **Check the door seal, hinges and latch; replace ovens with visible door damage.** — Door integrity is the dominant variable in leakage measurements.
- **Measure at 5 cm around the door perimeter with an RF meter that reads up to at least 20 mW/m².** — Most consumer RF meters saturate near a running microwave; check the meter's range before concluding.

## Measure with

- Broadband RF power-density meter
- Microwave oven leakage tester

## Related records

- [Power density](https://emfbase.com/quantities/power-density): Radiofrequency energy flow per unit area — µW/m² on consumer RF meters, mW/cm² in FCC rules, W/m² in ICNIRP guidelines. 1 mW/cm² = 10 W/m² = 10,000,000 µW/m².

## Sources

- `fda-1030-10` U.S. Government Publishing Office (eCFR). *21 CFR 1030.10 — Microwave ovens (radiation emission performance standard)*. https://www.ecfr.gov/current/title-21/chapter-I/subchapter-J/part-1030/section-1030.10 — regulation, link checked 2026-08-12
- `fda-microwave` U.S. Food and Drug Administration. *Microwave Ovens*. https://www.fda.gov/radiation-emitting-products/resources-you-radiation-emitting-products/microwave-oven-radiation — government, link checked 2026-08-12
- `fcc-part18` U.S. Government Publishing Office (eCFR). *47 CFR Part 18 — Industrial, Scientific, and Medical Equipment (includes microwave ovens)*. https://www.ecfr.gov/current/title-47/part-18 — regulation, link checked 2026-08-12

Data licence: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Dataset version 2026.08.1. Retrieved from EMFBase, https://emfbase.com.

This record is reference data, not medical or legal advice. Regulatory limits, scientific guidelines and precautionary values are labelled separately and answer different questions.