ANSI (American National Standards Institute) is a Non-Regulatory Agency that writes consensus standards with a particular emphasis (for example: ANSI Z87.1 for eye and face protection; ANSI Z89.1 for head protection; ANSI S3.19 for hearing protection or ANSI Z88.2 for respiratory protection). ATTENUATION The amount of sound reduction provided by a hearing protector. Higher numbers indicate more protection. This number is usually measured in decibels. DECIBEL (dB) Unit of measure for loudness, volume or intensity of sound. Noises at or above 85 decibels are potentially harmful to human hearing. DIELECTRIC A non-conductor of electricity or electrical current. EPA (Environmental Protection Agency) OSHA (Occupational Safety & Health Administration) is a Regulatory Agency that enforces regulations requiring the use of personal protective equipment. PARTICULATES Particles such as dust, mist, fume, smoke or spray that are small enough to be inhaled. NIOSH (National Institute of Occupational Safety & Health) is a Regulatory Agency that tests and approves respiratory protection. NRR (Noise Reduction Rating) a rating system set up by the EPA as a guideline that indicates the amount of potential protection a hearing protection device will give when tested to ANSI S3.19-1974. RATCHET a toothed wheel adjustment device that prevents backward motion.