Environmental Engineering Reference
In-Depth Information
are. burns. and. slight. shocks. that. can. lead. to. injuries. or. even. heart. failure.. Under.
certain. conditions,. even. a. small. amount. of. current. can. result. in. ibrillation. of. the.
heart.and.eventual.death..A.shock.can.also.cause.the.user.to.fall.off.a.ladder.or.other.
elevated.work.surface.
To. protect. the. user. from. shock,. tools. must. either. have. a. three-wire. cord. with.
ground,. be. grounded,. be. double. insulated,. or. be. powered. by. a. low-voltage. isola-
tion. transformer.. Three-wire. cords. contain. two. current-carrying. conductors. and. a.
grounding. conductor.. One. end. of. the. grounding. conductor. connects. to. the. tool's.
metal. housing.. The. other. end. is. grounded. through. a. prong. on. the. plug.. Anytime.
an. adapter. is. used. to. accommodate. a. two-hole. receptacle,. the. adapter. wire. must.
be.attached.to.a.known.ground..The.third.prong.should.never.be.removed.from.the.
plug.. Double. insulation. is. more. convenient.. The. user. and. the. tools. are. protected.
in.two.ways:.by.normal.insulation.from.the.wires.inside.the.tool,.and.by.a.housing.
that..cannot.conduct.electricity.to.the.operator.in.the.event.of.a.malfunction..These.
.general.practices.should.be.followed.when.using.electric.tools:
•.
Electric.tools.should.be.operated.within.their.design.limitations.
•.
Gloves.and.safety.footwear.are.recommended.during.the.use.of.electric.tools.
•.
When.not.in.use,.tools.should.be.stored.in.a.dry.place.
•.
Electric.tools.should.not.be.used.in.damp.or.wet.locations.
•.
Work.areas.should.be.well.lighted.
Powered.abrasive.grinding,.cutting,.polishing,.and.wire.bufing.wheels.create.spe-
cial.safety.problems.because.they.may.throw.off.lying.fragments..Before.an.abrasive.
wheel.is.mounted,.it.should.be.inspected.closely.and.sound-.or.ring-tested.to.ensure.
that.it.is.free.from.cracks.or.defects..To.test,.wheels.should.be.tapped.gently.with.a.light.
nonmetallic.instrument..If.the.wheel.sounds.cracked.or.dead,.it.could.ly.apart.in.oper-
ation.and.therefore.must.not.be.used..A.robust.and.undamaged.wheel.will.give.a.clear.
metallic.tone.or.“ring.”.To.prevent.the.wheel.from.cracking,.the.user.should.be.sure.it.
its.freely.on.the.spindle..The.spindle.nut.must.be.tightened.enough.to.hold.the.wheel.
in.place,.without.distorting.the.lange..Follow.the.manufacturer's.recommendations..
Care.must.be.taken.to.ensure.that.the.spindle.wheel.does.not.exceed.the.abrasive.wheel.
speciications.. Due. to. the. possibility. of. a. wheel. disintegrating. (exploding). during.
start-up,.employees.should.never.stand.directly.in.front.of.the.wheel.as.it.accelerates.
to.full.operating.speed..Portable.grinding.tools.must.be.equipped.with.safety.guards.
to.protect.workers.not.only.from.the.moving.wheel.surface,.but.also.from.lying.frag-
ments.in.case.of.breakage..In.addition,.when.using.a.powered.grinder,
•.
Always.use.eye.protection.
•.
Turn.off.the.power.when.not.in.use.
•.
Never.clamp.a.hand-held.grinder.in.a.vise.
PoWder-ActuAted tools (29 cFr 1910.243)
Powder-.or.explosive-actuated.tools.operate.like.a.loaded.gun.and.should.be.treated.
with. the. same. respect. and. precautions.. In. fact,. they. are. so. dangerous. that. they.
