WAC 246-366-110 sets sound control standards for Washington State school classrooms, requiring that background noise in new construction not exceed NC-35 on the noise criterion curve, with actual noise levels capped at 45 dBA during normal operation. Industrial and vocational classrooms have separate limits, with ambient noise not to exceed 65 dBA when exhaust systems are running. In music and vocational education areas, student noise exposure is strictly regulated by duration, and hearing protection must be provided if exposure limits are exceeded.Open full document
Notes
Washington Administrative Code section 246-366-110 establishes sound control requirements for school classrooms, including noise limits for new construction, exemptions for existing portable classrooms, and maximum noise exposure levels for vocational education and music areas. The regulation specifies background noise limits (NC-35, 45 dBA), industrial classroom noise limits (65 dBA), and provides a table of permissible noise exposure durations. It also requires hearing protectors when noise levels exceed specified limits in vocational and music settings.