What is the categorical exclusion provision in FCC RF exposure rules and what devices qualify?

The categorical exclusion provision in FCC RF exposure rules (47 CFR 1.1307(b)) exempts certain low-power transmitters from the requirement to perform an RF exposure evaluation, recognizing that their maximum possible exposure is so far below the safety limits that evaluation is unnecessary. A device qualifies for categorical exclusion if its effective radiated power is below a specified threshold that ensures the exposure limit cannot be exceeded under any use condition. The thresholds depend on: the operating frequency, the type of device (portable vs. mobile vs. fixed), and the exposure scenario (general public vs. occupational). For portable devices (operated within 20 cm of the body): at 300 MHz-1.5 GHz: excluded if ERP less than or equal to 0.5 mW. At 1.5-6 GHz: excluded if EIRP less than or equal to 3 mW (varies by frequency). Above 6 GHz: excluded if EIRP less than or equal to frequency-dependent thresholds from KDB 447498 (e.g., approximately 1 mW at 24 GHz). For mobile devices (operated more than 20 cm from the body): the thresholds are higher because the exposure decreases with distance. At 300 MHz-6 GHz: excluded if EIRP less than or equal to approximately 10-100 mW (frequency-dependent). For fixed transmitters (towers, base stations): categorical exclusion applies if the facility's total ERP in any direction is below the threshold for the specific frequency. Devices that commonly qualify for categorical exclusion: Bluetooth Low Energy (BLE) devices (transmit power approximately 0-4 dBm / 1-2.5 mW), low-power Wi-Fi (below approximately 100 mW EIRP for some configurations), passive RFID readers (low duty cycle, low power), and some IoT sensors.