Environmental Engineering Reference
In-Depth Information
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5.. If.an.STS.is.identiied,.employees.must.be.itted.or.reitted.with.adequate.
hearing. protectors,. shown. how. to. use. them,. and. required. to. wear. them..
Employees.must.be.notiied.within.21.days.from.the.time.the.determination.
is.made.that.their.audiometric.test.results.show.an.STS..Some.employees.
with.an.STS.may.need.to.be.referred.for.further.testing.if.the.professional.
determines. that. their. test. results. are. questionable,. or. if. they. have. an. ear.
problem. of. a. medical. nature. that. is. thought. to. be. caused. or. aggravated.
by. wearing. hearing. protectors.. If. the. suspected. medical. problem. is. not.
thought. to. be. related. to. wearing. hearing. protection,. employees. must. be.
informed.that.they.should.see.a.physician..If.subsequent.audiometric.tests.
show. that. the. STS. identiied. on. a. previous. audiogram. is. not. persistent,.
employees. whose. exposure. to. noise. is. less. than. a. TWA. of. 90. dBA. may.
discontinue.wearing.hearing.protectors..An.annual.audiogram.may.be.sub-
stituted.for.the.original.baseline.audiogram.if.the.professional.supervising.
the. program. determines. that. the. employee's. STS. is. persistent.. The. origi-
nal. baseline. audiogram,. however,. must. be. retained. for. the. length. of. the.
employee's. employment.. This. substitution. will. ensure. that. the. same. shift.
is.not.repeatedly.identiied..The.professional.also.may.decide.to.revise.the.
baseline.audiogram.if.an.improvement.in.hearing.occurs..This.will.ensure.
that. the. baseline. relects. actual. hearing. thresholds. to. the. extent. possible..
Audiometric. tests. must. be. conducted. in. a. room. meeting. speciic. back-
ground.levels.and.with.calibrated.audiometers.that.meet.American.National.
Standard.Institute.(ANSI).speciications.of.SC-1969.
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6.. Hearing.protectors.must.be.available.to.all.workers.exposed.to.8-hour.TWA.
noise.levels.of.85.dBA.or.above..This.requirement.will.ensure.that.employ-
ees. have. access. to. protectors. before. they. experience. a. loss. in. hearing..
Hearing.protectors.must.be.worn.by.(1).employees.for.any.period.exceeding.
6.months.from.the.time.they.are.irst.exposed.to.8-hour.TWA.noise.levels.
of. 85. dBA. or. above—this. must. be. done. until. they. receive. their. baseline.
audiograms.in.situations.where.baseline.audiograms.are.delayed.because.it.
is.inconvenient.for.mobile.test.vans.to.visit.the.workplace.more.than.once.
a. year;. (2). employees. who. have. incurred. standard. threshold. shifts. since.
these. workers. have. demonstrated. that. they. are. susceptible. to. noise;. and.
(3) employees.exposed.over.the.permissible.exposure.limit.of.90.dBA.over.
an.8-hour.TWA..Employees.should.decide,.with.the.help.of.a.person.who.
is. trained. in. itting. hearing. protectors,. which. size. and. type. of. protectors.
are.most.suitable.for.their.working.environment..Protectors.selected.should.
be. comfortable. to. the. wearer. and. offer. suficient. attenuation. to. prevent.
hearing.loss..Hearing.protectors.must.adequately.reduce.the.severity.of.the.
noise.level.for.each.employee's.work.environment.(see.Figure 23.11)..The.
employer.must.reevaluate.the.suitability.of.the.employee's.present.protec-
tors.whenever.there.is.a.change.in.working.conditions.that.may.cause.the.
hearing. protector. being. used. to. be. inadequate.. If. workplace. noise. levels.
increase,.employees.must.be.given.more.effective.protectors..The.protector.
must.reduce.employee.exposures.to.at.least.90.dBA.and.to.85.dBA.when.
an.STS.has.already.occurred.in.the.worker's.hearing..Employees.must.be.
