WAC 246-366-110
Sound control. (1) In new construction,
plans submitted under WAC 246-366-040 shall specify ventilation
equipment and other mechanical noise sources in classrooms are
designed to provide background sound which conforms to a noise
criterion curve or equivalent not to exceed NC-35. The owner
shall certify equipment and features are installed according to
the approved plans.
(2) In new construction, the actual background noise at any
student location within the classroom shall not exceed 45 dBA
(Legx) and 70 dB (Leqx) (unweighted scale) where x is thirty
seconds or more. The health officer shall determine compliance
with this section when the ventilation system and the ventilation
system's noise generating components, e.g., condenser, heat pump,
etc., are in operation.
(3) Existing portable classrooms, constructed before January
1, 1990, moved from one site to another on the same school
property or within the same school district are exempt from the
requirements of this section if the portable classrooms meet the
following:
(a) Noise abating or noise generating features shall not be
altered in a manner that may increase noise levels;
(b) The portable classrooms were previously in use for
general instruction;
(c) Ownership of the portable classrooms will remain the
same; and
(d) The new site is in compliance with WAC 246-366-030(3).
(4) In new construction, the maximum ambient noise level in
industrial arts, vocational agriculture and trade, and industrial
classrooms shall not exceed 65 dBA when all fume and dust exhaust
systems are operating.
(5) The maximum noise exposure for students in vocational
education and music areas shall not exceed the levels specified
in Table 1.
TABLE 1
MAXIMUM NOISE EXPOSURES PERMISSIBLE
Duration per day
(hours)
Sound Level
(dBA)
8
hours
85
6
hours
87
4
hours
90
3
hours
92
2
hours
95
1-1/2
hours
97
1
hour
100
1/2
hour
105
1/4
hour
110
Students shall not be exposed to sound levels equal to or
greater than 115 dBA.
(6) Should the total noise exposure in vocational education
and music areas exceed the levels specified in Table 1 of
subsection (5) of this section, hearing protectors, e.g., ear
plugs, muffs, etc., shall be provided to and used by the exposed
students. Hearing protectors shall reduce student noise exposure
to comply with the levels specified in Table 1 of subsection (5)
of this section.