(Effective September 1, 2025)
Noise control—Operation and maintenance requirements.
School officials shall:
(1) Maintain the background noise at any student location within classrooms constructed after January 1, 1990, at or below 45 dBA (Leqx) where x is 30 seconds or more. Background noise levels must be determined when the ventilation system and the ventilation system's noise generating components, such as the condenser and heat pump, are operating and the room is unoccupied by students.
(2) Maintain the background noise level at any student location in laboratories and shops with local exhaust ventilation systems constructed after January 1, 1990, at or below 65 dBA (Leqx) where x is 30 seconds or more. Background noise levels must be determined when all ventilation equipment is operating and the room is unoccupied by students.
(3) Maintain noise exposure for students below the maximum levels in Table 1.
Table 1
Maximum Noise Exposures Permissible
Duration per day (hours) | Sound level (dBA) |
8 | 85 |
6 | 87 |
4 | 90 |
3 | 92 |
2 | 95 |
1-1/2 | 97 |
1 | 100 |
1/2 | 105 |
1/4 | 110 |
(4) Not allow student exposure to sound levels equal to or greater than 115 dBA.
(5) Provide and require students to use personal protective equipment, for example ear plugs or muffs, where noise levels exceed those specified in Table 1. Personal protective equipment must reduce student noise exposure to comply with the levels specified in Table 1.
[Statutory Authority: RCW
43.20.050. WSR 10-01-174, 10-12-018, 11-10-080, 13-09-040, 15-09-070, 17-14-055, 19-14-107, 21-14-056, 22-14-021, 23-16-005, and 24-14-089, § 246-366A-105, filed 12/22/09, 5/21/10, 5/3/11, 4/11/13, 4/15/15, 6/28/17, 7/2/19, 7/1/21, 6/24/22, 7/19/23, and 6/28/24, effective 9/1/25.]