NANOSH Hunting for Nanoparticles

A Year in the Life of an Aerosol Scientist

I.L. Tuinman

I.L. Tuinman

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Project NANOSH: Nanoparticle Occupational Safety and Health

Measurements on site: can we find and characterize a nanoparticle health hazards in workplace environments?

Filtration: how well are nanoparticles filtered by respiratory protection filters

I.L. Tuinman

NANOSH Nanoparticle Occupational Safety and Health

Oberdorster and other authors published data showing nanoparticles can be more toxic than micron-sized particles

Some nanoparticles can even cross the brain barrier

Unintentional production of man-made nanoparticles was already high but increasingly nanoparticles are produced intentionally because of their improved properties and miniaturization of instruments

Maybe standard Personal Protective equipment does not provide proper protection

I.L. Tuinman

Content NANOSH-project

Characterization of nanoparticles (WP1)Perform measurements to determine Workplace Exposure (WP2)

Design a proper protocol for such measurements

Interpret the data

Test respiratory filters or respirators against nanoparticles

Test toxicology of nanoparticles (not discussed here) in 3 WP: genotoxicity, pulmonary inflammation and the effect of particles on microcirculation

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Occupational Hygiene: on site measurements

Total measurement equipment >100 kg, k€500 was transported in a small van from site to site

ELPISMPSCondensation Particle Counters (Portacounts)Personal samplerNSAM/ LQ1/Aerotrak 9000for active surface area

TEM photograph of fumed silica collected with a personal sampler

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Electrical Low Pressure Impactor, ELPI

+ Large size range (30 nm-10 µm)

+ Fast: high time resolution combined with some size resolution (12 size classes)

+ Large concentration range

+ Sample analysis afterwards possible

Measurement of exposure to ultrafine/nanoparticles

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Typical Result ELPI emptying bags with dust particles into a filling system

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Typical Result CPC emptying bags with dust particles into a filling system

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Why filter tests with Nanoparticles?Authors like Balazy et al. Ann. Occup. Hyg. 50(3), 2006 found filters with the most penentrating particle size in the nanoparticleRegion as shown in the graphs below

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Parameters tested

Filter Materials

Test Aerosols: NaCl and Carbon black

Air Flow(s): 1 cm/s and 10 cm/s (corresponds to 95 l/min in facelets)

Test set-up: adapted EN143 set-up with SMPS (TSI 3080) for

measurement

Filtration test set-up

• Three contributing test houses, HSL, TNO, and CIOP, tested six selected filters with NaCl and one other test aerosol

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Types of filter materials to be included

A defined selection of electrostatic and mechanical air filter materials in sheet form should be obtained covering the basic filter types applied in RPE and ventilation systems:

Electrostatically spun polycarbonate fibers

Electrostatically charged split fibers

Meltblown

Nanofibers

Glass fiber filter

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Collisonnebulizer

Diffusion dryer

Aerosol mixer

Dry, clean air

To rExcess aerosol flow

Filter test chamber

36 or 3.6 l/min

SMPS with DMA 3085 and UCPC 3786

Controlled flow through filter

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Results Electret A

10 100 10001

10

P NaCl 1 cm/s

P NaCl 10 cm/s

P CB 1 cm/s

P CB 10 cm/s

Particle diameter (nm)

Pene

trat

ion

(%)

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Results Electret B

10 100 10001

10

NaCl 1 cm/s

NaCl 10 cm/s

CB 1 cm/s

CB 10 cm/s

Dp (nm)

Pene

trat

ion

(%)

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Results low-efficiency electret filter

10 100 10001

10

100

NaCl 1 cm/s

NaCl 10 cm/s

CB 1 cm/s

CB 10 cm/s

Dp (nm)

Pene

trat

ion

(%)

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Results non-electret filter

10 100 10000.01

0.1

P NaCl 1 cm/s

P NaCl 10 cm/s

P CB 1 cm/s

P CB 10 cm/s

Dp (nm)

Pene

trat

ion

(%)

I.L. TuinmanNANOSH

Conclusions and Remarks

It is very difficult to measure an increase in nanoparticles in workplaces due to the height of and fluctuations in the backgroundExperiments in clean rooms can add valuable information.

Personal samplers can show significant exposure to manufactured nanoparticles

High efficiency electret filters tend to have their most penetrating particle size in the nanoparticle range. This has to be taken into account when selecting and testing respirators for workplaces where nanoparticles are expected.

I.L. TuinmanNANOSH

Thank you for your attention!

Point of Contact for TNO Respiratory Protection and Clothing

Frans van Gemerden

Email: frans.vangemerden@tno.nlTel: +31 6 52803608