When must double ear protection be worn?

Double ear protection must be worn in environments where noise levels exceed 104 dB, as recommended by the Occupational Safety and Health Administration (OSHA). This typically occurs in industries such as construction, manufacturing, and aviation, where loud machinery or equipment is in use. Additionally, it may be necessary in situations where single hearing protection does not provide adequate attenuation for prolonged exposure to high noise levels. Always refer to specific workplace regulations and safety guidelines for precise requirements.