Safe Handling of Safe Handling of NanomaterialsNanomaterials

Presented by:Presented by:Presented by:Presented by:Ron Pearson, M.S., CIHRon Pearson, M.S., CIH

Environmental Health & Safety, Inc.Environmental Health & Safety, Inc.

Today’s presentation will Today’s presentation will notnotcover safety issues related to:cover safety issues related to:

�� FlammabilityFlammability�� ExplosivityExplosivity�� ExplosivityExplosivity�� ReactivityReactivity�� Note: a number of the graphics used Note: a number of the graphics used

in this presentation were excerpted in this presentation were excerpted from the U.S. EPA “Nanotechnology from the U.S. EPA “Nanotechnology White Paper”, February, 2007White Paper”, February, 2007

Nanoparticles are found in many Nanoparticles are found in many places we may not consider...places we may not consider...

�� Welding fumesWelding fumes�� Diesel exhaustDiesel exhaust�� Smoke from cooking indoorsSmoke from cooking indoors�� Smoke from cooking indoorsSmoke from cooking indoors�� Smoke from candlesSmoke from candles

What is an What is an ““ engineeredengineered nanoparticle”?nanoparticle”?

�� There are multiple characterization schemesThere are multiple characterization schemes�� Most common definition is a particle <100 nm, Most common definition is a particle <100 nm,

designed and manufactured by peopledesigned and manufactured by people�� Forms:Forms:

�� Aggregated Aggregated -- group of particles that are tightly bonded group of particles that are tightly bonded �� Aggregated Aggregated -- group of particles that are tightly bonded group of particles that are tightly bonded (e.g. ‘sintered’, ‘fused’)(e.g. ‘sintered’, ‘fused’)

�� Agglomerated Agglomerated -- group of particles (typically held group of particles (typically held together by “Van together by “Van derder Waals” forces) easily broken Waals” forces) easily broken apart by handlingapart by handling

�� Shapes:Shapes:�� Spherical Spherical �� IrregularIrregular�� TubularTubular

Examples of Examples of Engineered NanoparticlesEngineered Nanoparticles

�� Carbon Carbon NanotubesNanotubes -- carbon atoms (single or multicarbon atoms (single or multi--layer), arranged in a cylindrical tubelayer), arranged in a cylindrical tube�� Needle type of shape similar to some types of Needle type of shape similar to some types of

asbestos asbestos -- concerns regarding similar hazard(?)concerns regarding similar hazard(?)�� “Quantum Dots” “Quantum Dots” -- metallic particle assemblies, with metallic particle assemblies, with �� “Quantum Dots” “Quantum Dots” -- metallic particle assemblies, with metallic particle assemblies, with

unique physical properties:unique physical properties:�� electrical electrical �� opticaloptical�� magnetic magnetic �� catalyticcatalytic

Some products currently utilizing Some products currently utilizing nanotechnology nanotechnology

Health Electronics Household Misc.Air filtersSunscreenAntibacterial

Computercomponentsand

Canola oilGolf clubsSkis

LubricantsCoatings

AntibacterialtreatmentsStainResistors

anddisplays

SkisCosmeticsToothpaste

Increasing ComplexityIncreasing Complexity

Public Awareness and Regulatory Public Awareness and Regulatory TrendsTrends

�� The introduction of new technologies The introduction of new technologies in the past (e.g. nuclear power) goes in the past (e.g. nuclear power) goes through a predictable coursethrough a predictable course

DEVELOPMENTUSE

SOCIAL CONCERN

REGULATION

RESOLUTION

PrecautionaryPrinciple ??

Public Awareness and Regulatory Public Awareness and Regulatory TrendsTrends

�� 2007 2007 -- Berkeley, CA Berkeley, CA -- City ordinance City ordinance enacted requiring researchers and enacted requiring researchers and manufacturers to disclose manufacturers to disclose use/manufacture of nanoparticlesuse/manufacture of nanoparticlesuse/manufacture of nanoparticlesuse/manufacture of nanoparticles

Red Herring?Red Herring?�� Germany Germany -- “Magic “Magic NanoNano” Sealing Spray” Sealing Spray�� Sealing spray for glass/ceramic surfacesSealing spray for glass/ceramic surfaces�� Within 3 days of being on the market, > 150 Within 3 days of being on the market, > 150

consumers reported strong cough, shortness of consumers reported strong cough, shortness of breath, and some with pulmonary edema after breath, and some with pulmonary edema after useuseuseuse

�� Health effects were determined to be related to an Health effects were determined to be related to an additive additive -- no no nanonano--sized particles were even sized particles were even present (referred to thickness of applied film)present (referred to thickness of applied film)

Nanoparticle hazards Nanoparticle hazards

�� Unfortunately, the very same Unfortunately, the very same physicophysico --chemical properties that make them chemical properties that make them attractive for use, also make them attractive for use, also make them unpredictable in their consequences for unpredictable in their consequences for deleterious effects on humans and the deleterious effects on humans and the deleterious effects on humans and the deleterious effects on humans and the environment….environment….

�� In general In general -- a smaller particle of identical a smaller particle of identical chemical composition is thought to be chemical composition is thought to be more hazardous than a larger particlemore hazardous than a larger particle

Nanoparticle hazards Nanoparticle hazards --background informationbackground information

�� The behavior of nanoparticles in the body The behavior of nanoparticles in the body is very different from larger particles of the is very different from larger particles of the same element/compound same element/compound -- e.g. permeation e.g. permeation of the “bloodof the “blood --brain barrier”brain barrier”

�� Epidemiological studies suggest exposure Epidemiological studies suggest exposure �� Epidemiological studies suggest exposure Epidemiological studies suggest exposure to ultrafine particles (generally nonto ultrafine particles (generally non --’engineered’ nanoparticles) increases ’engineered’ nanoparticles) increases cardiopulmonary hazardscardiopulmonary hazards

�� Dermal exposure hazard is also suggested Dermal exposure hazard is also suggested by several studiesby several studies

�� Particle size, surface area, and surface Particle size, surface area, and surface activity may all influence toxicityactivity may all influence toxicity

Lung Absorption of ParticlesLung Absorption of Particles

�� The most important characteristics are The most important characteristics are aerosol size and water solubilityaerosol size and water solubility

�� Particles Particles of 2 to 5 um deposited mainly in of 2 to 5 um deposited mainly in tracheobronchiolartracheobronchiolar regions, cleared by regions, cleared by ciliated portionsciliated portionsciliated portionsciliated portions

�� Particles Particles <1 um penetrate to the alveolar <1 um penetrate to the alveolar sacs of the lungs, may be absorbed into sacs of the lungs, may be absorbed into bloodblood

The BloodThe Blood --brain barrierbrain barrier

�� Unique physiological feature Unique physiological feature in the human body in the human body -- is less is less permeable than are most other permeable than are most other areas of the bodyareas of the bodyLipid/fat solubility plays an important roleLipid/fat solubility plays an important role�� Lipid/fat solubility plays an important roleLipid/fat solubility plays an important role

�� A few chemicals can enter the brain by A few chemicals can enter the brain by carriercarrier--mediated processes mediated processes -- e.g. e.g. methylmercurymethylmercury

�� Many Many nanoparticlesnanoparticles are thought to pass are thought to pass through the bloodthrough the blood --brain barrier readilybrain barrier readily

Nanoparticle hazards Nanoparticle hazards --background informationbackground information

�� A primary difficulty in conducting toxicity A primary difficulty in conducting toxicity studies is generating a reliably sized and studies is generating a reliably sized and measurable particle stream for inhalation measurable particle stream for inhalation studiesstudies

�� SelfSelf --mitigating behavior of some mitigating behavior of some nanoparticlesnanoparticles : : �� SelfSelf --mitigating behavior of some mitigating behavior of some nanoparticlesnanoparticles : : aggregation chainaggregation chain --formation formation sedimentationsedimentation

�� 3 groups of particles (by size):3 groups of particles (by size):�� Small (< 80 nm) Small (< 80 nm) -- agglomerate quickly, settleagglomerate quickly, settle�� Large (>2000 nm) Large (>2000 nm) -- coarse, settle quicklycoarse, settle quickly�� Intermediate (80 Intermediate (80 -- 2000 nm) 2000 nm) -- ‘accumulate’, but ‘accumulate’, but

can stay suspended in air for days to weeks can stay suspended in air for days to weeks

“Raw” Carbon Nanotubes Agglomerated Nanotube

Environmental Fate of Environmental Fate of NanoparticlesNanoparticles

�� BioavailabilityBioavailability -- can the material be taken can the material be taken into a ‘target organ’ to cause ill effectsinto a ‘target organ’ to cause ill effects

�� BioaccumulationBioaccumulation -- how likely is it to be how likely is it to be stored in the body for extended time stored in the body for extended time stored in the body for extended time stored in the body for extended time periodsperiods

�� BiotransformationBiotransformation -- can the material be can the material be changed to a more toxic compoundchanged to a more toxic compound

�� None of these issues are well understood None of these issues are well understood yetyet

NanoparticleNanoparticleExposure Assessment Exposure Assessment

�� Air sampling methods have had Air sampling methods have had limited validationlimited validationThere is significant uncertainty There is significant uncertainty �� There is significant uncertainty There is significant uncertainty regarding evaluation and control of regarding evaluation and control of potential potential exposuresexposures

�� However, recent advances have been However, recent advances have been made made –– very situationvery situation --dependentdependent

NanoparticleNanoparticleExposure AssessmentExposure Assessment

�� Comprehensive exposure Comprehensive exposure assessment has to consider many assessment has to consider many factors:factors:�� particle sizeparticle size�� particle sizeparticle size�� particle surface areaparticle surface area�� particle shapeparticle shape�� surface chemistrysurface chemistry�� mass concentrationmass concentration�� degree of agglomerationdegree of agglomeration

Occupational ExposuresOccupational Exposures

Hazard ControlsHazard Controls

�� Control bandingControl banding may be may be the best the best available risk management framework available risk management framework at this time, given:at this time, given:

�� Lack of toxicity dataLack of toxicity data�� Lack of toxicity dataLack of toxicity data�� Lack of standards exposure Lack of standards exposure

monitoring methodsmonitoring methods�� Lack of occupational exposure Lack of occupational exposure

standardsstandards

Haz.Class

Haz.Class

Haz.Class

Haz.Class“Dustiness”

QuantityHandled

A B C DSolids or Sealed Containers Any LB1 LB1 LB1 LB1Suspensions with Minimal Any LB1 LB1 LB1 LB1

Classification scheme for Classification scheme for selecting labselecting lab --scale controls*scale controls*

Suspensions with MinimalPotential for DropletDispersion

Any LB1 LB1 LB1 LB1

< 100 mg LB1 LB1 LB1 LB1Granular/ AgglomeratedPowders or DispersibleSuspensions

100 mg – 1 kg LB1 LB1 LB1 LB1-2

< 100 mg LB1 LB1 LB2 LB2Powders100 mg – 1 kg LB1 LB1 LB2 LB2< 100 mg LB1 LB1-2 LB2 LB3Highly Dispersible Powders100 mg – 1 kg LB1 LB2 LB2 LB3

* credit to AIHA Distance Learning Program

Lab Hazard ControlsLab Hazard ControlsLB 1 LB 2 LB 3• Open bench operations.• Keep sample containers

sealed.• Clean surfaces around

analytical equipment

• Use fume hoodsor local exhaustto collect vaporsand gases fromlab analyses.

• Use local exhaust

• Consider placinganalytical equipmentinside ventilatedenclosures.

analytical equipment• frequently.• Collect waste in sealed

containers with spillbasins.

• Use local exhaustif powders arereleased.

NOTE RE ENGINEERING CONTROLS (!) - Containmentmust be ‘complete’ (no leaks), or nanoparticles may escapeand become suspended in room air

Respirators as PPERespirators as PPE

�� NIOSH Certifies particle filtering NIOSH Certifies particle filtering respirators by ‘challenging’ them with respirators by ‘challenging’ them with either: either: �� sodium chloride aerosols (75 nm sodium chloride aerosols (75 nm �� sodium chloride aerosols (75 nm sodium chloride aerosols (75 nm

particle size)particle size)�� or or dioctyldioctyl phthalate (185 nm particle phthalate (185 nm particle

size)size)�� Leakage around the faceLeakage around the face--seal is likely to seal is likely to

pose a greater exposure risk than pose a greater exposure risk than penetration through the filtration matrix penetration through the filtration matrix (but on the same order as a gas or vapor)(but on the same order as a gas or vapor)

General Hazard General Hazard Reduction StrategiesReduction Strategies

�� Designate handling areas Designate handling areas -- post, limit accesspost, limit access�� If material is a dry powder, or pelletized If material is a dry powder, or pelletized --

determine if it can be handled as a liquid or determine if it can be handled as a liquid or slurryslurryMinimize Minimize aerosolizationaerosolization potential potential -- slow stirring slow stirring �� Minimize Minimize aerosolizationaerosolization potential potential -- slow stirring slow stirring speeds, airtight transfer points, pouringspeeds, airtight transfer points, pouring

�� Purchase dry material in prePurchase dry material in pre--weighed portionsweighed portions�� Use local exhaust where possible to ventilate Use local exhaust where possible to ventilate

transfer points, bulk material handlingtransfer points, bulk material handling�� Use wet wiping methods and HEPA vacuums Use wet wiping methods and HEPA vacuums

only to clean up any spillsonly to clean up any spills