# Why do FCC and ICNIRP limits differ?

> Same thermal basis, different units, averaging masses and breakpoints; some countries add precautionary layers such as Switzerland's installation values.

- Canonical URL: https://emfbase.com/questions/why-do-fcc-and-icnirp-limits-differ
- Collection: Direct answers
- Record id: `questions:why-do-fcc-and-icnirp-limits-differ`
- Status: verified
- Last verified: 2026-08-12
- JSON: https://emfbase.com/api/questions/why-do-fcc-and-icnirp-limits-differ
- Also known as: FCC vs ICNIRP, why are EMF limits different by country

## Key values

- **Topic:** regulation

## Question

Why are U.S. and European EMF limits different numbers?

## Answer

They are built on the same thermal basis but use different units, averaging masses and frequency breakpoints. The FCC expresses public RF limits in mW/cm² and averages SAR over 1 gram of tissue; ICNIRP expresses reference levels in W/m² and averages local SAR over 10 grams, so a phone's published SAR differs between regions without any difference in the device. Some countries then add precautionary layers on top — Switzerland's installation limit values are roughly a tenth of ICNIRP's reference levels in field-strength terms — which is a policy choice, not a different reading of the science.

## Related records

- [FCC Maximum Permissible Exposure (47 CFR 1.1310)](https://emfbase.com/standards/fcc-mpe): Legally binding U.S. exposure limits for radiofrequency transmitters from 300 kHz to 100 GHz, adopted from NCRP and ANSI/IEEE recommendations in 1996 and reaffirmed in 2019.
- [ICNIRP 2020 RF guidelines (100 kHz–300 GHz)](https://emfbase.com/standards/icnirp-2020): International guidelines that most countries outside the U.S. adopt into law, covering 5G, Wi-Fi, Bluetooth, mobile phones and base stations.
- [Reference level vs basic restriction](https://emfbase.com/glossary/reference-level): ICNIRP's two-tier structure: basic restrictions are the dosimetric limits that matter biologically; reference levels are the externally measurable proxies derived from them.

## Sources

- `fcc-1310` U.S. Government Publishing Office (eCFR). *47 CFR § 1.1310 — Radiofrequency radiation exposure limits*. https://www.ecfr.gov/current/title-47/section-1.1310 — regulation, link checked 2026-08-12
- `icnirp-2020` International Commission on Non-Ionizing Radiation Protection (2020). *Guidelines for Limiting Exposure to Electromagnetic Fields (100 kHz to 300 GHz)*. https://www.icnirp.org/en/publications/article/rf-guidelines-2020.html — guideline, link checked 2026-08-12
- `ch-onir` Swiss Confederation (2000). *Ordinance relating to Protection from Non-Ionising Radiation (ONIR / NISV, SR 814.710)*. https://www.fedlex.admin.ch/eli/cc/2000/38/en — 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.