Environmental Engineering Reference
In-Depth Information
by.surface.characteristics.and.other.factors,.however..Results.from
in vitro
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cell.culture.studies.with.similar.materials.generally.are.supportive.of.the.
biological.responses.observed.in.animals.
Cytotoxicity.and.experimental.animal.studies.have.shown.that.changes.in.
the.chemical.composition,.structure.of.the.molecules,.or.surface.properties.
of.certain.nanomaterials.can.inluence.their.potential.toxicity.
Studies.in.workers.exposed.to.aerosols.of.manufactured.microscopic.(ine).
and.nanoscale.(ultraine).particles.have.reported.lung.function.decrements.
and. adverse. respiratory. symptoms;. however,. uncertainty. exists. about. the.
role. of. ultraine. particles. relative. to. other. airborne. contaminants. (e.g.,.
chemicals,. ine. particles). in. these. work. environments. in. causing. adverse.
health.effects.
Engineered.nanoparticles.whose.physical.and.chemical.characteristics.are.
like.those.of.ultraine.particles.should.be.studied.to.determine.if.they.pose.
health. risks. similar. to. those. that. have. been. associated. with. the. ultraine.
particles.
Although. insuficient. information. exists. to. predict. the. ire. and. explosion.
risk. associated. with. nanoscale. powders,. nanoscale. combustible. material.
could.present.a.higher.risk.than.coarser.material.with.a.similar.mass.con-
centration.given.its.increased.particle.surface.area.and.potentially.unique.
properties.due.to.the.nanoscale.
Some. nanomaterials. may. initiate. catalytic. reactions,. depending. on. their.
composition. and. structure,. that. would. not. otherwise. be. anticipated. from.
their.chemical.composition.alone.
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Nanomaterial-enabled. products. such. as. nanocomposites. and. surface. coatings,.
and.materials.comprised.of.nanostructures.such.as.integrated.circuits,.are,.accord-
ing. to. NIOSH,. unlikely. to. pose. a. risk. of. exposure. during. their. handling. and. use..
Some.of.the.processes.(formulating.and.applying.nanoscale.coatings).used.in.their.
production. may. lead. to. exposure. to. nanoparticles,. however.. Processes. generating.
nanomaterials. in. the. gas. phase,. or. using. or. producing. nanomaterials. as. powders.
or. slurries/suspensions/solutions. pose. the. greatest. risk. for. releasing. nanoparticles..
Maintenance. on. production. systems. (including. cleaning. and. disposal. of. materials.
from. dust. collection. systems). is. likely. to. result. in. exposure. to. nanoparticles. if. it.
involves.disturbing.deposited.nanomaterial.
The.following.workplace.tasks,.according.to.NIOSH,.may.increase.the.risk.of.
exposure.to.nanoparticles:
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Working. with. nanomaterials. in. liquid. media. without. adequate. protection.
(e.g.,.gloves).will.increase.the.risk.of.skin.exposure.
Working.with.nanomaterials.in.liquid.during.pouring.or.mixing.operations,.
or.where.a.high.degree.of.agitation.is.involved,.will.lead.to.an.increased.
likelihood.of.the.formation.of.inhalable.and.respirable.droplets.
Generating. nanoparticles. in. the. gas. phase. in. non-enclosed. systems. will.
increase.the.chances.of.aerosol.release.into.the.workplace.
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