Environmental Engineering Reference
In-Depth Information
table .
Case study using the xl insurance database: nano titanium dioxide [, ]
Risk analysis step
analysis
1..Identify.process.and.materials
Hydrolysis.and.calcinations.with.chemical.
additives.to.control.particle.size;.process.
currently.in.commercial.use
2...Characterize.materials.
and.processes
A...Collect.and.characterize.
data.on.material.
properties
Data.compiled.for.methane,.hydrochloric..
acid,.phosphoric.acid,.titanium.
tetrachloride,.carbon.dioxide.
B...Deine.manufacturing.
processes,.identify.
characteristics.that.
determine.risks
1...Prepare.aqueous.solution.of.TiCl
4
.in.
solution.with.HCl,.HPO
4
.
2...Vacuum-dry.solution.and.spray-dry.at.
200-250°C.to.produce.dry.TiO
2
.
3...Calcinate.at.600-900°C.for.0.5-8.hours.
to.produce.crystalline.nanostructure.
4...Wash.precipitate.with.C
2
H
5
OH,.dry,.and.
mill.to.nano-sized.particles.
3..Determine.relative.risk
A..Qualitative.Assessment
.Materials.with.very.high.risk.include.
phosphoric.acid.(toxicity),.titanium.
tetrachloride.(toxicity).
B...XL.Insurance.Database.
Methodology
exposure..The.tendency.for.many.nanomaterials.to.agglomerate.or.sorb.to.solids.may.
limit.that.potential.
In.the.end,.the.ield.of.nanotechnology.is.too.broad.and.as.yet.there.are.too.many.
unknowns.for.gross.generalizations.regarding.risks.and.rewards..Some.applications.
offer.true.innovation.and.possible.solutions.to.near-intractable.problems;.other.nano.
promises. may. be. largely. marketing. hype.. Some. hazards. —. speciic. to. particular.
materials.and.exposures.—.may.present.signiicant.risks.that.warrant.careful.control.
and. monitoring.. Others. may. fall. within. the. range. that. society. deems. acceptable..
At.this.stage.in.our.understanding.of.nanotechnology.and.the.environment,.Albert.
Einstein. may. have. offered. the. best. advice:. “Learn. from. yesterday,. live. for. today,.
hope.for.tomorrow..The.important.thing.is.not.to.stop.questioning.”
