engineered nanomaterials in construction: assessing
TRANSCRIPT
Engineered Nanomaterials in Construction: Assessing Exposure Risks and Controls, and Keeping Workers Informed
July 21, 2021
DOE Webinar Presentation
Gavin West, MPH, Director of Nanomaterials
Research
Bruce Lippy, Ph.D., CIH, CSP, FAIA
Nanomaterials Consultant to CPWR
After this session, you will be able to:
1. Define engineered nanomaterials and explain their use in construction
2. Measure exposures to engineered nanomaterials and implement effective exposure controls
3. Describe challenges and progress in hazard communication for nano
4. Explain how to access resources to keep workers informed, including outreach and training materials from CPWR
Who is familiar with CPWR?
CPWR administers BTMed
• Medical screening of DOE construction workers
• Individual health impacts from work on DOE sites
• ~40k screenings since 1996
• 98% satisfaction rate
• Partners: Duke, UMD, Zenith American Solutions, Building Trades Unions
Define engineered nanomaterials and explain their use in construction
Learning Objective 1
1 2 3 4
Who in the audience has dealt with engineered nanomaterials in the workplace?
What is nanotechnology?Science, engineering, and technology conducted at the size range of about 1 to 100 nanometers
https://www.nano.gov/nanotech-101/what/definition
A yard is roughly a meter
Think about cutting that into a billion sections
This nanoparticle is one million times smaller than an ant
x 1,000,000 x 1,000,000
Indy 500 racetrack, 2.5 miles long
What is an engineered nanomaterial?
An object 1 to 100 nanometers in at least 1 dimension created by human beings for some purpose
Image courtesy Dr. Zhong Wang, Georgia Tech
MAY 24-26 | AIHceEXP.org | 12
CPWR has identified over 750 construction materials reported to be nano-enabled
www.nano.elcosh.org
Paints & coatings
57%
Other products
43%
Paints and coatings comprise the bulk of the inventory
Concrete &
masonry
densifiers, sealers,
etc.
Cement
mixes
Cement
additives
Patching
compoundsOther
products
Concrete-related products make up about 30% of the inventory
Many different nanomaterials are reported for just these two categoriesProduct Nanomaterial Exposure Scenario
Paints and coatings
acrylic, acrylic-urethane, alumina, aluminum oxide, amorphous silica, boehmite, calcium hydroxide, carbon, carbon black, carbon nanotubes, ceramic, cerium oxide, clay, copper, fluorochemical, fluoropolymer modified nanoparticles, graphene fibers, hybrid nanoparticles, liquid acrylic resin, lithium, modified metal oxides, multi-walled carbon nanotubes, nano membranes, nanoemulsion of paraffin, nanohybrid particles, nanostructured/ nanocomposite surface, platinum, polycarbon/ate, polymer, polysiloxane, polyurethane hybrid, quartz, silane, silica, silicone, siloxane, silver, thin film, titanium, titanium dioxide, transoxide pigments, zinc oxide
spray application; abrasive blasting, cutting, grinding, and sanding of coated substrates
Cementitious materials
carbon nanofibers, graphene fibers, modified internal nanostructure, multi-walled carbon nanotubes, polycarbonate, polymer, quartz, silica fume, titanium dioxide
mixing, pouring, cutting, grinding, chipping, drilling, sweeping up dust
There are a wide range of exposure scenarios for products in the inventoryProduct
Category
Examples of Potential
Exposure Scenarios
Product
Category
Examples of Potential
Exposure ScenariosInsulation handling, application, cutting Drywall cutting and installationAdditives for coatings weighing, mixing Miscellaneous variousRoofing cutting, drilling, nailing HVAC spraying and manual applicationLubricants spraying or manual application to
construction equipment and tools
Prepregs mechanical abrasion
Surface preparation dermal exposure during handling, spray
application
Weatherproofing
membranes
cutting and installation
Thermal sprays welding, grinding thermal spray coated
substrates
Additives for asphalt weighing, mixing, milling, paving
Adhesives application, removal, separation or
machining of bonded substrates
Caulking installation and removal of windows,
door frames, masonry columnsAdditives for cement weighing, mixing Joint Sealants removal and renovation, mechanical
abrasion of adjacent materialsFlooring cutting and removal Lumber sanding and sawingGlass and solar panels cutting and installation Boiler additives cleaning and repairing boilers and
boiler surfacesMetal welding Fasteners little or no exposure potentialWeld overlays welding Fuel Additives construction equipment exhaust
Properties of nano-enhanced materials, like the insulation provided by these nanostructured aerogels, can be hard to replace
Photos courtesy Wikimedia and NASA
2.5 kg brick
supported by a
2-gram piece of
aerogel
Matches on a
piece of
aerogel over
a Bunsen
burner
Measure exposures to engineered nanomaterials and implement
effective exposure controls
1 2 3 4
Learning Objective 2
What’s different about sampling for nanoparticles?•
•
This Photo by Unknown Author is licensed under CC BY-SA-NC
Standard IH methods for dusts and metals are necessary but insufficient
Photo courtesy Earl Dotter
Direct reading instruments provide valuable information about airborne particles
Scanning Mobility Particle
Sizer & Optical Particle Sizer
Photo courtesy
Earl Dotter
• Size distribution• Concentration• Peak emissions• Effectiveness of controls
Indicative but not definitive proof of airborne ENMs
Electron microscopy is the only method to positively identify ENMs
• Chemical composition via energy dispersive spectroscopy (EDS)
• Size and shape
• Agglomeration
• Bound in a solid, suspended in liquid, or unbound
Nanocellulose cement enhancer
NEAT 2.0 describes how NIOSH integrates these methods to conduct comprehensive exposure assessments
Nanoparticle
Exposure
Assessment
Technique
Eastlake et al (2016) https://dx.doi.org/10.1080%2F15459624.2016.1167278
CPWR has conducted multiple exposure studies involving paints, coatings, and cementitious materials
We evaluated task-based
exposures in a test chamber
What might be different about sampling on a jobsite?
We used standard NIOSH methods for dusts and metals
Analyte NIOSH Method Media
Total
particulate
0500 37mm cassette with 5µm
pre-weighed, PVC filters
Respirable
particulate
0600 37mm cassette with 5µm
pre-weighed, PVC filters
Zinc oxide 7300/7303 37mm cassette with 5µm
pre-weighed, PVC filters
And compared elemental mass concentrations to NIOSH Recommended Exposure Limits (RELs) when available
https://www.cdc.gov/niosh/topics/nanotech/pubs.html
Most nanomaterials do not have a Recommended Exposure Limit
Consequently, NIOSH is seeking comments on a draft report about developing categorical OELs or OEBs for engineered nanomaterials that lack sufficient experimental data to develop substance-specific OELs
https://www.federalregister.gov/documents/2021/07/13/2021-14801/draft-approaches-to-developing-occupational-exposure-limits-or-bands-for-engineered-nanomaterials
In most of our studies, we concluded the risk of exceeding RELs under similar conditions was unlikely
Task Construction material
Nanomaterial Potential to exceed REL
Cut, drill, nail roofing tile TiO2 Unlikely
Spray wood sealant ZnO No REL
Sand wood sealant ZnO No REL
Spray paint TiO2 Yes
Sand paint TiO2 Unlikely
Spray Paint Ag Unlikely
When elemental mass concentrations exceed the REL, electron microscopy is needed to characterize physical properties and confirm the presence of engineered nanoparticles
Our studies and others show that ENMs tend to remain bound to the materials to which they are added
Paint spray droplets containing titanium dioxide nanoparticles
Sanding dust containing zinc oxide nanoparticles
Our research also shows that exposure controls used in construction are effective
Photo courtesy
Earl Dotter
Our worker training materials emphasize that respirators will work against nanoparticles
Great video on how filtration works!
Images courtesy 3M Corp and Wikimedia
3M half-face air-purifying respirator with P100 particulate filter
and organic vapor (OV) cartridgeshttps://www.youtube.com/watch?v=eAdanPfQdCA&feature=youtu.be&t=9
More detailed info on our exposure studies is provided in our publications
1. https://doi.org/10.1007/s11051-016-3352-y
2. https://doi.org/10.1080/15459624.2017.1296237
3. https://doi.org/10.1080/15459624.2018.1550295
4. https://doi.org/10.1080/15459624.2021.1910277
One important issue we plan to study moving forward is the effect of weathering on exposure
Mechanical force
Image credit: Mount Sinai/CHEP
Weathering
Photodecomposition
Thermal degradation
Hydrolysis
Image credit:
Wikimedia/
Famartin
Field
LaboratorySimulated Worker
Moving forward: Further integration of field,
simulated worker, and laboratory assessments
Slide courtesy of Dr. Aaron Erdely (NIOSH)
Describe challenges and progress in hazard communication for nano
1 2 3 4
37
Learning Objective 3
I am a proud Baltimorean with bragging rights
Toots Barger, 7 timeNational Duckpin Bowling
Champ
I began consulting with DOE in 1992 and still work on respiratory protection issues at the Hanford Tank Farms
Most interesting work of my career!
You can visualize our Hazcom challenge using this Yugo in this color
Photo courtesy Wikimedia Commons
Important context: SDSs were indicated as the preferred method of obtaining EHS info by nanotech firms
Lindberg and Quinn, 2007
A Survey of Environmental, Health and Safety Risk Management Information Needs and Practices among Nanotechnology Firms in the Massachusetts Region
Safe Work Australia found SDSs lacking (2010)
• Nano metals, metal oxides, silicates and carbon nanotubes
• (84%) were “not sufficient to fulfill an appropriate risk assessment”
• Many presented data for the bulk material “without any consideration of the validity of this information for the nano form.”
Korean Ministry of Labor and Employment surveyed 126,846 workplaces in 2014
J. Kim & I.J. Yu, BioMed Research International, Volume 2016
Photo courtesy Wikimedia and Minseong Kim
Korean national survey confirmed inadequacy of nano SDSs
• 340 (0.27%) workplaces handling nanomaterials
• 125 SDSs evaluated for 6 nanomaterials
• 17.6% identified the hazard of nanomaterials
• 3.2% stated cleanup method for dry manufactured nanomaterials
• 3.2% stated it was a manufactured nanomaterial (for CNTs)
J. Kim & I.J. Yu, BioMed Research International, Volume 2016
A NIOSH study found serious problems with nanoSDSs after 2012 Hazcom revision (n=67, some from eLCOSH)
satisfactory
needed improvement
needed significant improvement
0
10
20
30
40
50
60
70
80
90
Pe
rce
nt
of
Safe
ty D
ata
She
ets
“…cannot be relied upon to offer adequate information on inherent H&S hazards, including handling and storage of ENMs.”
Hodson, Eastlake & Herbers, J Chem Health Saf, 2019 45
2 (3%)
12 (18%)
53 (79%)
We have seen little useful information on nano in SDSs we’ve collected
•735 products in eLCOSH as of 4-14-21
•We could not find a SDS for roughly half
•Only about 10% of the products with SDSs mention anything related to nano
ISO has published a 2012 technical report for writing nano SDSs that is quite good, if old!
I will be leading a revision to the report as a Hopkins Associate
ISO/TR 13329
Nanomaterials: Preparation of
Material Safety Data Sheet (MSDS)
The ISO recommends a precautionary approach
Provide an SDS for nanomaterials and nanomaterial-containing products regardless of whether the material is classified as hazardous
There is currently no requirement to identify nanomaterials in safety data sheets (SDSs) in this country
Photo courtesy J. Vinton Schafer & Sons, Inc. and CCBC
49
Upcoming revisions to OSHA’s Hazcom standard should improve Nano SDSs
To meet the requirements of the Global Harmonization System, manufacturers must report particle size and “If available and appropriate”
• Shape
• Aspect ratio
• Surface area
50
The requirements in the EU under REACH are far more extensive
Figure 1, Appendix for nanoforms applicable to the Guidance on Registration and Substance Identification,
European Chemicals Agency (ECHA), December 2019
Under REACH, the registration dossier for nano must include
• Size
• Shape
•Aspect ratio
•Assembly structure
•Rigidity
•Crystallinity
• Surface functionalization
• Surface areahttps://echa.europa.eu/regulations/nanomaterials
CPWR is developing an online tool to improve safety data sheets for nano-enabled construction materials
Background
Engineered nanomaterials, which are extremely small particles that often exhibit unusual chemical and
physical properties, are increasingly found in a variety of products used in the construction industry. Currently,
several hundred such products have been identified by CPWR (https://nano.elcosh.org/), primarily including
paints, coatings, and sealants, but are also found in concrete, roofing materials, flooring, lubricants, insulation,
and other materials. When construction workers use these materials, they can be exposed to dust or mist
containing nanoparticles. Although some nanomaterials have been found to be toxic in animals, most have not
been adequately tested and, consequently, the risk of exposure to them is unknown.
Purpose of the Tool
This tool is designed to help manufacturers, distributors, and importers of nano-containing products evaluate
their corresponding SDSs and improve them to ensure that construction employers and workers who use their
products are fully informed about the presence of nanomaterials and protective measures that should be taken.
The tool may also be useful to employers and workers to evaluate the adequacy of SDSs they rely upon and to
contact their vendors if there are questions about the information presented.
How to Use This Tool
The tool is organized into the 16 sections of an SDS that follow the organization specified in the Globally
Harmonized System of Classification and Labelling of Chemicals (GHS) (8th edition, United Nations, 2019)
and required in the U.S. by the Occupational Safety and Health Administration’s (OSHA) Hazard
Communication Standard (HCS) (29 CFR 1910.1200). For each of these sections, a series of questions are
presented for the user to answer either Yes or No
Click Here to Begin
We’re developing an industrial hygiene field guide focused on sampling on construction jobs
Condensation particle counter
10 – 1000 nm range (p/cc)
Optical particle counter
300 – 10,000 nm range (p/l)
Scanning mobility particle sizer
Multiple size bins < 100 nmStandard industrial hygiene methods
Explain how to access resources for keeping workers informed, including outreach and training
materials from CPWR
1 2 3 4
55
Learning Objective 4
CPWR funded a Small Study focused on nanotechnology awareness
Laura Boatman and Debra Chapman, State Building and Construction Trades Council of CA
Explore awareness among CA construction unions and employers about nano
• Received 253 written surveys from Survey Monkey (goal was 100)
• Followed up with 21 key informant interviews
• Conducted phone interviews with 5 individuals from 4 California government agencies
https://www.cpwr.com/research/small-studies-program/
Two important quotes from the study:
• “Comprehensive nanotechnology training is virtually non-existent.” (2% of survey participants had received training and most were insulators.)
• “Two California agencies have the potential to gather information from nanomaterial manufacturers and make that information public, however, neither is doing anything with nanomaterials at this time.”
We delivered train-the-trainer curricula tailored for specific audiences this year despite the pandemic
We will share our curricula and deliver training for construction audiences
IUPAT National PETE CCCHST Insulators
We encourage using our nano-SDS exercise. Each group gets different SDSs and answers these questions:
1. Does the SDS identify the nano-sized component?
2. Does it have any cautionary language about nano?
3. Does it use the PEL for the “macro” sized material?
Machinists doing SDS exercise, Aug
2016
We continue adding to our collection of nano toolbox talks, which received over 10,000 downloads in one year
https://www.cpwr.com/research/research-to-practice-r2p/r2p-library/toolbox-talks/
Photo courtesy: Morgan Zavertnik and Hoar Construction
*
In Spanish, too
The news & info section of elcosh nanohas a collection of articles by topic
61
The European
Trade Union Institute
has worker
materials
BG BAU’s 360 Nanorama is a great training tool for construction work
http://nano.dguv.de/nanorama/bgbau/
The AIHA Nano and Advanced Materials Working Group should be considered a valuable asset for industrial hygienists
https://www.aiha.org/get-involved/volunteer-groups/nano-and-advanced-materials-working-group
In 2011, a truck transporting several bags each holding 750-kg (1650 lbs) of photocatalytic titanium dioxide (TiO2) lost its cargo. Road maintenance workers did the clean up.
We have trained hazmat instructors using an exercise of a real spill of ENMs
65
Finally, we continue to present our work to a range of stakeholders
Gavin West, [email protected] office
Bruce Lippy, PhD, CIH, CSP, FAIHA
410-916-0359 cell
Thanks! Questions or comments?
DOE quiz: what
facility is this?