Environmental Engineering Reference
In-Depth Information
exposure.. Time. is. an. exposure. limiter. and. a. mechanism. that. allows. employers. to.
spread.exposure.over.several.workers..The.time.part.of.the.work.cycle.that.allows.
for.minimal.risk.exposure.to.transpire.is.during.a.shift.when.fewer.employees.are.
present.to.be.exposed..Often,.second.and.third.shifts.are.times.when.fewer..workers.
are.present..Shielding.is.frequently.considered.the.least.acceptable.approach.to.risk.
control..Barriers.or.personal.protective.equipment.should.be.the.risk.control.of.last.
resort.. With. occupational. safety. and. health,. other. approaches. to. risk. control. are.
often.employed.
Many. ways. to. control. hazards. have. been. used. over. the. years. but. usually. these.
can. be. broken. down. into. ive. primary. approaches.. The. preferred. ways. to. do. this.
are.through.engineering.controls,.awareness.devices,.predetermined.safe.work.prac-
tices,. and. administrative. controls.. When. these. controls. are. not. feasible. or. do. not.
provide.suficient.protection,.an.alternative.or.supplementary.method.of.protection.
is.to.provide.workers.with.personal.protective.equipment.(PPE).and.the.know-how.
to.use.it.properly.
E
nginEEring
C
ontrols
When.a.hazard.is.identiied.in.the.workplace,.every.effort.should.be.made.to.eliminate.
it.so.that.employees.are.not.harmed..Elimination.may.be.accomplished.by.designing.
or. redesigning. a. piece. of. equipment. or. process.. This. could. be. the. installation. of. a.
guard.on.a.piece.of.machinery.that.prevents.workers.from.contacting.the.hazard..The.
hazard.can.be.engineered.out.of.the.operation..Another.way.to.reduce.or.control.the.
hazard.is.to.isolate.the.process,.such.as.in.the.manufacture.of.vinyl.chloride.used.to.
make.such.items.as.plastic.milk.bottles,.where.the.entire.process.becomes.a.closed.
circuit..This.will.result.in.no.one.being.exposed.to.vinyl.chloride.gas,.which.is.known.
to.cause.cancer..Thus,.any.physical.controls.that.are.put.in.place.are.considered.the.
best.approach.from.an.engineering.perspective..Keep.in.mind.that.you.are.a.consumer.
of. products.. Thus,. at. times. you. can. leverage. the. manufacturer. to. implement. safe-
guards.or.safety.devices.on.products.that.you.are.looking.to.purchase..Let.your.vendor.
do.the.engineering.for.you.or.do.not.purchase.their.product..This.may.not.always.be.a.
viable.option..To.summarize.the.engineering.controls.that.can.be.used,.the.following.
may.be.considered:
•.
Substitution
•.
Elimination
•.
Ventilation
•.
Isolation
•.
Process.or.design.change
A
wArEnEss
D
EviCEs
Awareness.devices.are.linked.to.the.senses..They.are.warning.devices.that.can.be.heard.
and.seen..They.act.as.alerts.to.workers.but.create.no.type.of.physical..barrier..They.are.
