# SAR (specific absorption rate)

> Watts absorbed per kilogram of tissue, the dosimetric basis of phone compliance testing — 1.6 W/kg over 1 g in the U.S., 2 W/kg over 10 g under ICNIRP.

- Canonical URL: https://emfbase.com/glossary/sar
- Collection: Glossary
- Record id: `glossary:sar`
- Status: verified
- Last verified: 2026-08-12
- JSON: https://emfbase.com/api/glossary/sar

## Key values

- **Category:** measurement

## Definition

SAR quantifies RF power deposition in tissue. It is measured in a liquid-filled phantom with the device transmitting at maximum power in its worst-case configuration, which is why a device's SAR is a compliance figure rather than a description of everyday exposure. Because the U.S. averages over 1 gram and ICNIRP over 10 grams, published SAR values for the same phone differ between regions and must not be compared directly.

## Sources

- `fcc-2-1093` U.S. Government Publishing Office (eCFR). *47 CFR § 2.1093 — Radiofrequency radiation exposure evaluation: portable devices*. https://www.ecfr.gov/current/title-47/section-2.1093 — 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

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.