Environmental Engineering Reference
In-Depth Information
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3.. Basic.causes.(management.safety.policies.and.decisions,.and.personal.factors).
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See diagram at the beginning of this chapter.)
D
irECt
C
AusE
Most.accidents.are.caused.by.the.unplanned.or.unwanted.release.of.large.amounts.of.
energy,.or.of.hazardous.materials..In.a.breakdown.of.accident.causes,.the.direct.cause.
is. the. energy. or. hazardous. material. released. at. the. time. of. the. accident.. Accident.
investigators. are. interested. in. inding. out. what. the. direct. cause. of. an. accident. is.
because.this.information.can.be.used.to.help.prevent.other.accidents,.or.to.reduce.the.
injuries.associated.with.them.
Energy. is. classiied. in. one. of. two. ways.. It. is. either. potential. or. kinetic. energy..
Potential energy
.is.deined.as.stored.energy.such.as.a.rock.on.the.top.of.a.hill..There.
are.usually.two.components.to.potential.energy..They.are.the.weight.of.the.object.
and.its.height..The.rock.resting.at.the.bottom.of.the.hill.has.little.potential.energy.
as.compared.to.the.one.at.the.top.of.the.hill..Some.examples.of.potential.energy.are.
depicted.in.Table 7.1.
The. other. classiication. is.
kinetic energy,
. which. is. best. described. as. energy.
motion.. Kinetic. energy. depends. on. the. mass. of. the. object.. Mass. is. the. amount. of.
matter.making.up.an.object,.such.as.an.elephant.has.more.matter.than.a.mouse,.and.
therefore.more.mass..The.weight.of.an.object.is.a.factor.of.the.mass.of.an.object.and.
the.pull.of.gravity.on.it..Kinetic.energy.is.a.function.of.an.object's.mass.and.its.speed.
of.movement.or.velocity..A.bullet.thrown.at.you.has.the.same.mass.as.one.shot.at.
you,.but.the.difference.lies.in.the.velocity—and.there.is.no.disagreement.as.to.which.
has. more. kinetic. energy. or. potential. to. cause. the. greatest. damage. or. harm.. Some.
examples.of.kinetic.energy.are.given.in.Table 7.2.
Energy.comes.in.many.forms,.and.each.has.its.own.unique.potential.for.release.
of.energy.and.it.ensuing.form.of.danger.and.potential.for.an.accident.and.the.trauma.
that.it.can.cause..The.forms.of.energy.are.pressure,.biological,.chemical,.electrical,.
thermal,.light,.mechanical,.and.nuclear..Examples.of.each.form.of.energy.are.found.
in.Table 7.3.
If. the. direct. cause. is. known,. then. equipment,. materials,. and. facilities. can. be.
redesigned.to.make.them.safer;.personal.protection.can.be.provided.to.reduce.injuries;.
tABle 7.1
examples of Potential energy
Compressed.gases
Hand.or.power.tool
Object.at.rest
Liqueied.gas
Effort.to.move.an.object
Dust
Spring-loaded.objects
Unfallen.tree
Electrically.charged.component
Radiation.source
Idling.vehicle
Chemical.source
Disengaged.equipment
Biological.organism
Flowable.material
