{
  "id": "quantities:specific-absorption-rate",
  "collection": "quantities",
  "slug": "specific-absorption-rate",
  "name": "Specific absorption rate (SAR)",
  "summary": "Watts of RF power absorbed per kilogram of tissue — the dosimetric quantity behind phone compliance testing, limited to 1.6 W/kg over 1 g in the U.S. and 2 W/kg over 10 g under ICNIRP.",
  "status": "verified",
  "lastVerified": "2026-08-12",
  "data": {
    "aliases": [
      "SAR",
      "W/kg"
    ],
    "quantityId": "specific-absorption-rate",
    "symbol": "SAR",
    "siUnit": "W/kg",
    "units": [
      {
        "symbol": "W/kg",
        "name": "watt per kilogram",
        "toBase": 1
      },
      {
        "symbol": "mW/g",
        "name": "milliwatt per gram",
        "toBase": 1
      },
      {
        "symbol": "mW/kg",
        "name": "milliwatt per kilogram",
        "toBase": 0.001
      }
    ],
    "measures": "Energy absorption in tissue during near-field exposure, measured in a liquid-filled phantom at maximum transmit power. Because the U.S. averages over 1 g and ICNIRP over 10 g, the two published numbers for the same phone are not comparable.",
    "related": [
      "limits:fcc-sar-partial-body",
      "limits:icnirp-2020-sar-local"
    ]
  },
  "sources": [
    {
      "id": "fcc-2-1093",
      "title": "47 CFR § 2.1093 — Radiofrequency radiation exposure evaluation: portable devices",
      "publisher": "U.S. Government Publishing Office (eCFR)",
      "url": "https://www.ecfr.gov/current/title-47/section-2.1093",
      "kind": "regulation",
      "retrieved": "2026-08-12"
    },
    {
      "id": "icnirp-2020",
      "title": "Guidelines for Limiting Exposure to Electromagnetic Fields (100 kHz to 300 GHz)",
      "publisher": "International Commission on Non-Ionizing Radiation Protection",
      "url": "https://www.icnirp.org/en/publications/article/rf-guidelines-2020.html",
      "year": 2020,
      "kind": "guideline",
      "retrieved": "2026-08-12"
    }
  ],
  "links": {
    "self": "https://emfbase.com/api/quantities/specific-absorption-rate",
    "html": "https://emfbase.com/quantities/specific-absorption-rate",
    "markdown": "https://emfbase.com/quantities/specific-absorption-rate.md",
    "collection": "https://emfbase.com/api/quantities"
  }
}