University of North Carolina at Chapel Hill Catherine Brennan

NANOPARTICLE AIR MONITORING IN A UNIVERSITY RESEARCH SETTING

• Nanotechnology Safety Program• Nanoparticle Instruments• Preliminary Data – Nanomedicine Clean Room• Future Plans – TiO2 and Carbon nanotubes• Challenges at Universities

Overview

Nanotechnology at UNC Chapel Hill Aerosol Research, Nanomedicine,

Materials Science, Environmental Sciences, Use in Research Animals

Center for Nanotechnology in Drug Delivery – 4 Investigators

Carolina Center of Cancer Nanotechnology Excellence – 4 Project Leaders, 11 Investigators

Current “Known” Nano Investigators at the University ~ 34

Nanotechnology Safety Webpage

Nanomaterial Risk Level (NRL)

NRL Type of Nanomaterial

Practices Engineering Controls Personal Protective Equipment (PPE)

1 Polymer matrix Standard Laboratory Practices including:Lab Safety Plan should be updated with NRL definedLabeling of storage containers of nanomaterials with both the chemical contents and the nanostructure form

Fume hood or biological safety cabinet (Class II Type A1, A2 vented via a thimble connection, B1 or B2)

Standard PPE (lab coat, gloves, safety glasses with side shields)

2 Liquid dispersion NRL-1 practice plus:Use secondary containment for containers that store nanomaterialsWipe contaminated areas with wet disposable wipesDispose of contaminated cleaning materials as segregated nanomaterial waste

Fume hood or biological safety cabinet (Class II Type A1, A2 vented via a thimble connection, B1 or B2) or approved vented enclosure (e.g., Flow Sciences vented balance safety enclosure [VBSE])

NRL-1 practice plus:Nitrile glovesSafety goggles

3 Dry powders or aerosols

NRL-2 practice plus:Vacuum with HEPA-equipped hand vacuum cleanerLabel work areas with “Caution Hazardous Nanoscale Materials in Use”

Fume hood or biological safety cabinet (Class II Type A1, A2 vented via a thimble connection, B1 or B2) or approved vented enclosure (e.g., Flow Sciences vented balance safety enclosure [VBSE]). HEPA filtered exhaust preferred for fume hoods containing particularly “dusty” operations.

NRL-2 practice plus:N95 respirators are required if work operation must be done outside of containment

4 Dry Powders or aerosols of parent materials with known toxicity or hazards

NRL-3 practice plus:Baseline medical evaluation or employees including physical exam, pulmonary function test (PFT) and routine blood work.Access to the facility should be permitted only to persons who are knowledgeable about the hazards of the material and the specific control measures implemented to avoid exposures and/or environmental releases. These control measures should include work practices (SOPs), engineering controls, spill and emergency procedures, personal protective equipment, disposal procedures, and decontamination/clean up procedures. Department procedures should address the designation and posting of the laboratory, how access will be controlled, and any required entry and exit protocols.

Fume hood or biological safety cabinet (Class II Type B1 or B2) or glove box or approved vented enclosure (e.g., Flow Sciences vented balance safety enclosure [VBSE]). HEPA filtered exhaust with Bag-In/Bag-Out capability preferred for hoods, BSCs, and gloveboxes.

NRL-3 practice plus:Need determined and respirator selected with reference to the engineering controls in use and potential for aerosol generation

Nanotechnology Safety Policy(2010)

Principal Investigators Designate and address use and disposal as part of

individual lab safety plan (CHP) Generate SOPs for specific work operations involving

nanomaterials Ensure lab personnel are trained in hazards and

uncertainties associated with nanomaterials Laboratory Employees

Review Lab Safety Manual chapter on nanotechnology and Nanomaterial Risk Level table

Take Nanotechnology Safety online training Review and follow SOPs for specific work operations

Nanotechnology Safety Policy EHS

Review and provide feedback on lab safety plans

Provide hazard assessments upon request Continuously update nanotechnology safety

resources (Lab Safety Manual, Nanomaterial Risk Level table, Nanotechnology Safety training)

Annually review and update the policy as new findings and regulations are announced

NIOSH Guidance Document

Approaches to Safe Nanotechnology: Managing the Health and Safety Concerns Associated with Engineered Nanomaterials (2009)

Suggested Air Sampling Strategy – Nanoparticle Emission Assessment Technique (NEAT) Use of direct read instruments (CPC and OPC) to

determine particle number concentration at potential emission sources compared to background

If elevated, collect filter based, source specific air samples One analyzed by Transmission Electron Microscope (TEM) or

Scanning Electron Microscope (SEM) for particle identification and characterization

One analyzed for elemental mass concentration

UNC Direct Read Instruments Condensation Particle Counter (CPC)

TSI 3007 Hand-held (3.8 lbs) Uses IPA to condense on particles so they can be

counted Measures total number of particles per cubic

centimeter (#/cm3) independent of chemical identity and size

Particle size range between 10-1000 nm Range of detection 0-100,000 #/cm3

Is material (regardless of size) being released? Determine sources Determine appropriate controls

UNC Direct Read Instruments Optical Particle Counter (OPC)

MetOne HHPC-6 Hand-held (2.2 lbs) Optical counting using laser light scattering Measures total number of particles per liter (P/L)

independent of chemical identity Over 6 size ranges (300nm, 500nm, 700nm,

1000nm, 2000nm, 5000nm) Range of detection 0 to 70,000 P/L Can determine size range of particles based on

concentration Used in conjunction with CPC

UNC Direct Read Instruments Nanoparticle Surface Area Aerosol

Monitor TSI AeroTrak 9000

Portable (15.8 lbs) Diffusion charger plus electrometer Indicates surface area of particles deposited in

lung (Tracheobronchial and Alveolar regions) Particle size range between 10-1000 nm Concentration range

TB = 1 to 2500 m2/cc A = 1 to10,000 m2/cc

Nanomedicine Clean Room

Multi-user space (Class 10,000) Incorporation of anti-neoplastic agents into particles

BSL 2 hood

Walk in hood

Bench

Chemical Hood

refrige.

cabinet

freezercabinet

Controlled humidity room

On top of shelf

refrig

e.

Be

ad

H

arve

ster

Clean Room – CPC Data

Background measurements during group meeting Placed in center of room on shelf above bench top Every 60 seconds over 1.47 hr time period

Mean (#/cm³) 14.5Min. (#/cm³) 11.0Max. (#/cm³) 28.0Std. Dev. (#/cm³) 2.29Sample Time (secs) 6420

Time (secs)

#/c

m3

Clean Room – OPC Data

Time (hr:min:secs)

Pa

rtic

les/

Lite

r

Background (03/22/11)

Clean Room – CPC Data

Date Start/End Time

Range (#/cm

3)

Mean (#/cm

3)

Averaging

Interval (second

s)

Sample

Length (hr:mi

n)

3/22/11 1:46pm/3:33pm

11-28 14.5 60 1:47

3/24/11 8:35am/12:29pm

4-35 10.2 60 3:54

3/29/11 8:37am/2:34pm

6-97 17.0 60 5:57

Follow-up measurements during active lab work Did see minor spikes but mostly tracks with mean

Background

03/24/11 03/29/11

Clean Room - OPC

Can not compare OPC and CPC side to side Spikes do sometimes track with time

03/24/11 (OPC Data)03/24/11 (CPC Data)

Clean Room

Moved next to bead harvester Instruments placed on top of fridge

BSL 2 hood

Walk in hood

Bench

Chemical Hood

refrige.

cabinet

freezercabinet

Controlled humidity room

refrig

e.

Be

ad

H

arve

ster

Clean Room – CPC Data (3/31)

Date Start/End Time

Range (#/cm3)

Mean (#/cm3)

Averaging Interval (seconds

)

Sample Length (hr:min)

3/22/11 1:46pm/3:33pm

11-28 14.5 60 1:47

3/31/11 8:47am/1:58pm

2-9300 492.6 60 5:11

Saw highest numbers and definite spikes Harvester process captures nanoparticles in solution

03/31/11

Clean Room – OPC (3/31)

OPC data off due to vibration? Both instruments affected by movement,

opening closing doors, equipment cycling No further data - lab contact left university

03/31/11 (CPC Data)

Future - Aerosolization Research Nebulizing nanomedicine particles into

mice Occurs in ductless hood in common

animal procedure room Project currently on hold

Titanium Dioxide

New guidelines released from NIOSH CURRENT INTELLIGENCE BULLETIN 63 -

Occupational Exposure to Titanium Dioxide (2011)

Delineates differences between fine and ultrafine (<100 nm) TiO2 and sets different OELs

Outlines new exposure limit for ultrafine TiO2 = 0.3 mg/m3 as 10-hr TWA

Also lists ultrafine TiO2 as a potential occupational carcinogen

Future TiO2 Monitoring Plans UNC Physics lab synthesizing TiO2

nanotubes (5 nm diameter, 50 nm length) Concerns about weighing out dry

nanotube powder on bench-top Happened to be moving to a new lab

space Background measurements taken before

occupying Will follow up once research begins

Future TiO2 Monitoring Plans UNC Environmental

Sciences fog chamber used to study nanoparticle aerosols (NiO, TiO2)

Need to periodically clean chamber (Particles attach to poly and in between cracks)

Recommended PPE for cleaning but will also do monitoring

Carbon Nanotubes

NIOSH draft Current Intelligence Bulletin: Occupational Exposure to Carbon Nanotubes and Nanofibers

Proposed REL of 7 g/m3 as 8-hr TWA Several UNC physics lab working on

synthesis of carbon nanotubes Manipulate in dry form outside

engineering controls Future plans to perform monitoring

Challenges at a University

Vast variety of nanomaterial research projects

Day to day processes change, timing not consistent as in industrial setting

Multiple users in same space working on different independent projects

Type of nanoparticles (chemical composition, size, surface area, shape, etc.) being worked on changes constantly

Users/Contacts change frequently

Challenges at a University - EHS Each hazard assessment is an independent

research project (lack of time for EHS Professional) Must keep up to date on current literature and

regulations Start working on specific assessment and abruptly

ends due to someone leaving or change in research

Handheld or portable instruments are expensive OPC ~ $4000 CPC ~ $9000 Surface Area ~ $10,000

The Good News

Education on unknown hazards of nanomaterials is working and researchers are requesting hazard assessments

Technical nano conferences are integrating EHS concerns and researchers are coming back asking questions

Researchers are interested in how their nanoparticles are behaving (clean room)

Spirit of collaboration especially in early stages of nanomaterial risk assessment

What University’s Need

EHS nanotechnology specialists to perform monitoring

Guidance from NIOSH on monitoring protocols (training course?)

Collaboration with Environmental Sciences/Aerosol Researchers to work together on “projects” and publish results

EHS professionals sharing their experiences

Catherine BrennanChemical Hygiene OfficerEnvironment, Health & Safetycrbrennan@ehs.unc.edu919-843-5331

Contact Information:

Condensation Particle Counter Particles drawn into

instrument Particles pass through

chamber with alcohol vapor

Air flows through condensor and vapor condenses on particles

Particles scatter laser light which is then detected by photo-detector

* Information taken from TSI website

Optical Particle Counter

Particles drawn through a focused laser

Resulting scattered light is collected by a mirror and focused on photo-detector

Concentration derived from count rate and particle size from the pulse heights

* Information taken from TSI website

Diffusion Charger (Surface Area) Clean air is ionized Ions and aerosol sample

streams are mixed and the particles are charged

Excess ions are removed Acts as an inlet conditioner or

a size selective sampler Ion trap voltage can be

changed between TB and A response

Particles pass through electrometer and are collected on conductive filter

Amplifies and measures charge on surface of particle

* Information taken from TSI website