Environmental Engineering Reference
In-Depth Information
table .
Case study using the nano Risk Framework: titanium dioxide []
Framework step
analysis
1...Describe.Material.and.
Application
DuPont™.Light.Stabilizer.210.is.a.surface-treated.form.of.TiO
2
..The.product.
absorbs.and.scatters.ultraviolet.(UV).light;.addition.of.this.product.to.a.
polymer.protects.the.material.from.UV.damage.when.exposed.to.sunlight.
DuPont™.Light.Stabilizer.210.will.be.transported.to.plastics.producers.in.
plastic.bags,.where.it.will.be.combined.with.other.ingredients.and.mixed.
with.molten.polymer;.it.will.comprise.<3%.of.the.end.product.Potential.
applications.include.outdoor.furniture,.toys,.and.sheeting.to.protect.
greenhouses..Use.of.light.stabilizers.will.extend.the.product.life.and.
thereby.reduce.the.volume.of.plastics.being.landilled.
2..Proile.Lifecycle(s)
DuPont™.Light.Stabilizer.210.is.a.white.powder.with.particle.sizes.
centered.in.the.range.of.130-140.nm..10-20.wt%.falls.within.the.nano.
range.(i.e.,.<100.nm)..The.particles.are.dense.polyhedral.TiO
2
.crystals.
surface.treated.to.control.chemical.reactions..The.particles.cannot.be.
broken.down.by.mechanical.action,.and.their.composition.will.not.
substantially.change.throughout.the.life.cycle.
Toxicity.studies.showed.no.signiicant.difference.between.the.effects.of.
DuPont™ Light.Stabilizer.210.and.pigmentary.TiO
2
..Toxicity.testing.
demonstrated.low.hazard.to.ish.and.invertebrates.and.indicated.medium.
concern.for.algae,.potentially.due.to.the.light-blocking.effects.
Titanium.occurs.naturally.in.the.environment..No.established.analytical.
method.can.distinguish.between.the.titanium.in.DuPont™.Light.
Stabilizer.210.and.naturally.occurring.titanium.
No.accepted.protocols.for.assessing.the.bioaccumulation.potential.of.
nanomaterials.exist.
Worker.exposure.should.be.low.under.normal.operating.conditions..
Monitoring.during.production.and.handling.indicated.that.airborne.
concentrations.were.below.the.acceptable.exposure.limit.of.2.mg/m
3
..If.
exposure.limits.were.exceeded,.workers.were.to.don.half-mask.
respirators.with.P100.ilters.
Exposure.is.expected.to.be.low.throughout.the.product.life.cycle.because.
potential.worker.exposure.is.well-managed;.due.to.the.low.production,.
use.of.engineering.controls,.and.properties.of.the.material,.releases.to.
the.environment.should.be.minimal;.and.the.polymer.end.product.should.
retain.the.DuPont™.Light.Stabilizer.210.unless.incinerated..Emissions.
from.incineration.should.be.low.due.to.the.low.concentrations.and.
emission.controls.on.incinerators.
3..Evaluate.Risks
Toxicity.studies.showed.no.signiicant.difference.between.the.effects.of.
DuPont™.Light.Stabilizer.210.and.pigmentary.TiO
2
;.both.show.low.hazard..
Further,.exposure.should.be.limited..Therefore,.“there.are.no.substantive.
risk.issues.associated.with.manufacture,.processing,.use.or.disposal.of.
DuPont™.Light.Stabilizer.”
4...Assess.Risk.
Management
Based.on.the.conclusions.of.Step.3,.few.additional.risk.management.
measures.were.recommended..Those.included.personnel.scheduling.and.
monitoring.during.non-routine.activities,.and.developing.recycling.
procedures..Some.additional.toxicity.testing.was.contemplated.
