Nanotechnology, Industrial Hygiene, and the Electric Power Industry s/eeiFall2014/ih/webb.pdf · The Promise of Nanotechnology Nanotechnology will leave virtually no aspect of life

Nanotechnology, Industrial Hygiene, and the Electric Power Industry

Paul J. Webb, CIH, CSP Colden Corporation

The Promise of Nanotechnology

“Nanotechnology will leave virtually no aspect of life untouched and is expected to be in widespread

use by 2020.”

- ASME.org

Source:

Top 5 Trends in Nanotechnology, by Nancy S. Giges, ASME.org

Nano, IH, and the Electric Power Industry, Fall 2014 Conference 4

The Promise of Nanotechnology

Follow the money: 2015 U.S. Federal Budget provides more than $1.5

billion for the National Nanotechnology Initiative (NNI)

Global market for nanotechnology estimated to reach $3.3 Trillion by 2018

Sources: National Nanotechnology Initiative: http://nano.gov/ PRNewswire-iReach, December 3, 2012 Nano, IH, and the Electric Power Industry, Fall 2014 Conference 5

http://nano.gov/

http://nano.gov/

Advantages of Nano-scale Materials

Altering materials at a molecular level, creates materials that tend to be lighter, stronger, and more reactive than materials made with larger

size particles of the same material

This all sounds fantastic but…. Is this technology creating something that could end up being harmful to us, and/or the environment?


The Potential Risks

Title from a recent article in Forbes.com:

Doctors Claim New Evidence That Nanotechnology Can Make Workers Sick

by Robert Bowman, Forbes.com

Source:

http://www.forbes.com/sites/robertbowman/2014/08/14/doctors-claim-evidence-that-nanotechnology-can-make-workers-sick/


The Potential Risks

Litigation - NRDC sues EPA over allowing the use of nanosilver:

NRDC says no to nanosilver March 1, 2012 / Advanced Textiles Source / In the Industry

“Nanosilver penetrates organs and tissues in the body that larger forms of silver cannot reach, like the brain, lung and testes.”

“Nanosilver has potentially devastating effects when released into the environment and potentially damaging effects when

absorbed by humans.”

- Dr. Jennifer Sass, senior scientist, NRDC health program


Nanotechnology Current Themes, good and bad (maybe)

Lots of optimism about the future of nanotechnology

Although relatively new, nanomaterials are already widely used in the workplace and our society

Also some concerns:

Speculation about possible long-term health consequences

including comparisons with asbestos


Topics for Discussion

Introduction to Nanotechnology

Relevance to Health and Safety

Nanotechnology and the Electric Power Industry

Exposure Assessment Considerations

Evaluation Techniques

Summary and Additional Resources



Introduction to Nanotechnology

Nanotechnology

Nanotechnology is a cross-disciplinary field that involves the creation and application of novel materials, devices and systems by control and restructuring of matter at dimensions of roughly 1 – 100 nanometers in size


Nanomaterials

Structures greater than atomic/ molecular dimensions but less than 100 nanometers

Structures that exhibits physical, chemical and/or biological characteristics associated with its nanostructure


Nanomaterials

Nanomaterials is a term that includes all nano-sized materials including:

Engineered nanoparticles

Ultrafine particles: Incidental nanoparticles (formed as a by-product)

Welding fumes, fossil fuel combustion

Any nano-objects that exist in nature (sea spray or particles formed through erosion)


Nanoparticles

A nanoparticle:

Is a nano-scale material (nanomaterial)

Can be described by its shape and size

May have unique physical, chemical or biological properties

May be heterogeneous, consisting of a core, and outer shell or coating


Nanoparticles are Tiny

Compared to a diameter of 100 nanometers :

is

Beach sand , 90 micrometers (µm) in diameter

900 times larger

Human hair, 50-70 µm in diameter

500 times larger

Dust, pollen, and mold, < 10 µm in diameter

100 times larger

Red blood cell, 7.5 µm in diameter

75 times larger

Combustion products, <2.5 µm in diameter

25 times larger

Red Blood Cell


Engineering Nanomaterials (ENMs)

Engineered Nano-Scale Materials (ENMs) include: carbon nanotubes, fullerenes, titanium dioxide (TiO2), carbon black, cobalt oxide (Co3O4), and nickel (Ni)

ENMs present a significant exposure potential since they can readily enter the body


Other Types of Nanoparticles (Ultrafine Particles)

Ultrafine particles are:

Defined as those less than 100 nm and qualify as nano-sized particles

Not purposefully manufactured and vary in composition and size

The result of combustion or friction processes or natural processes in the air or water

Source: EPA


Relevance to Health and Safety

For ENMs:

EHS practice will increasingly require a working knowledge of their health risk

As awareness grows, all stakeholders will want to know their risks from ENMs

For Ultrafine Particles:

Traditional exposure assessment may not adequately define hazard

A different approach is necessary


Toxicity of Nanoparticles

Key issue – composition vs. size

• Example: carbon

Large particles – e.g., carbon black - relatively nontoxic

Nano-scale size particle (e.g., carbon nanotubes, fullerenes) – toxicity is unknown

Even more so for functionalized nanoparticles


Smaller Size, Larger Numbers


Source: Biswas and Wu (2005)

Toxicity: Key Points

Surface area and particle number become much more important as the particles become smaller, compared to mass

For toxicological end points, mass may be a less important exposure metric than exposure metrics that depend on surface area or number


Dermal Exposure

Nanoparticles may act more like a gas than a particle

Normal intact skin appears to provide a barrier for many nanoparticles, although the risk of entry increases for flexed or abraded skin

Gloves and other protective equipment may not offer adequate protection

Dermal contact may serve as a route of entry for certain nanoparticles


Particle Mobility (Once in the body)

As particles reach the nanometer size range, they may become more biologically mobile:

Cross cellular boundaries from the alveolar region into the circulatory system

Pass through the skin

Travel through the olfactory nerve to the brain


Toxicity Observations

1. Factors: Surface area, chemical composition, particle number and surface reactivity (free radical)

2. Nano-size particles cause greater adverse inflammatory response

3. Carbon nanotubes induce dose-dependent lung inflammation

4. Can go through cell membrane into circulatory system and translocate to other organs (brain, kidney, CNS). Persistence in neuronal tissue is unknown

5. Dermal penetration may be a route of entry for some nanoparticles


Carbon Nanotube (CNT) Toxicity

Many studies published in the recent years have focused on CNT toxicity

End point studied:

Fibrosis

Inflammation of lung and cardiac tissue

Mesothelioma


Do CNTs Cause Mesothelioma?

Carbon nanotubes introduced into the abdominal cavity of mice show asbestos-like pathogenicity in a pilot study,

Source: Poland et al., Nature Nano., 2008

Induction of mesothelioma in mouse by intra-peritoneal application of multi-wall carbon nanotube,

Source: Takagi, et al.,J. Toxicol. Sci, 2008


Do CNTs Cause Mesothelioma?

“Here we show that exposing the mesothelial lining of the body

cavity of mice, as a surrogate for the mesothelial lining of the chest cavity, to long multi-walled carbon nanotubes results in asbestos-like, length-dependent, pathogenic behaviour… Our results suggest the need for further research and great caution before introducing such products into the market if long-term

harm is to be avoided.” Source: Poland et al., Nature Nano., 2008


Nanotechnology and the Electric Power Industry

Sustainability Applications


Sustainability

Sustainability is a major trend affecting investment decisions within the electric power industry

The effects are already evident in increased funding of alternative energy sources and reduction targets in CO2 emissions

Nanotechnology is being applied across the value chain to improve power generation, delivery, and storage efficiencies


Key Benefits to the Electric Power Industry

Nanostructured materials are designed to be superior to conventional materials in the following ways:

Stronger and lighter

Different magnetic properties that can be controlled

Better di-electric properties

Better conductors of heat or electricity


Relevance to Electric Power

Advanced nano-engineered materials increase efficiencies in:

Electricity Generation

Electrical Transmission and Distribution

Electrical Energy Storage

Reference: 2014 Outlook on Power & Utilities My take: By John McCue, Deloitte LLP


Electricity Generation

Polymer nano-composites: addition of nanomaterial improves di-electric qualities and strength

Nano-lubricants: improves efficiency by reducing friction coefficients for conventional power generation turbines

Evolving nanotechnologies are expected to find applications in all parts of the industry


Electricity T&D

Highly conductive carbon nanotubes can substantially cut energy loss from transmission lines

System Diagnostics: nano-sensors will help utilities

detect operations issues in advance by monitoring current and voltage along the grid, detecting the condition of underground cables, and evaluating transformers and other equipment


Electricity Storage

Supercapacitors have fast charge and discharge capabilities over hundreds of thousands of cycles, and are used in electrical storage in power grid applications

Nanomaterials and nanostructured surfaces improve energy

storage capacity by controlling charge transfer processes in these materials

Nano-infused electrodes use materials like carbon nanotubes to produce supercapacitors

Benefits include lighter and more powerful batteries and

capacitors


Product Development Areas

Nano-designed dielectrics: engineered to an exact specification results in improved response to

changing electric fields Electrical equipment applications: cables, bushings, surge arresters and

insulating materials

Nano-structured sliding bearing (in development):

Electrical equipment applications: switchgear operation without oil Lower operating costs and less environmental impact

Source: ABB Research and Development http://www.abb.com/cawp/seitp202/d0384d7076c42f3ec1256eef0040a58a.aspx


http://www.abb.com/cawp/seitp202/d0384d7076c42f3ec1256eef0040a58a.aspx

http://www.abb.com/cawp/seitp202/d0384d7076c42f3ec1256eef0040a58a.aspx

Exposure Assessment Considerations

Challenges

Measurement options

Combining methods


Exposure Assessment Challenges

1. Exposure Levels at which particles produce adverse health effects are generally known whereas there is limited toxicological data and OELs for nanoparticles

2. Sampling and Analytical methods include

microscopic and mass-based measurement of known materials. Analysis of ultrafine particles relies on non-specific direct reading measurement



3. Nanoparticle behavior: Nanoparticles behave differently than larger particles based on their unique size, shape and densities

4. Exposure Metrics: Debate continues over

what is the most appropriate method to measure exposure:

Total surface area? Mass concentration? Number concentration?



5. Interpretation of results: Real-time

instruments can measure nanoparticles, but most have significant biases and are not specific to the particle of interest (e.g., condensation particle counters, surface area monitors, etc.)

Example: using a particle counter to measure welding fumes, but the work occurs in an area with other sources of nanoparticles


Nanoparticle Measurement Options

Screening for nanoparticles

Particle counters and simple size analyzers

Specific Characterization

Filter-based samples for electron microscopy and elemental analysis

Collected at the source and at personal breathing zone

Use of less portable aerosol sizing equipment


Combining Methods

One option is to combine analytical and sampling methods using a combination of lab-based protocols along with the use of direct reading instruments

For ultrafine particles (non-ENMs), the use of direct reading instruments (DRIs) can provide a quick measure of workplace conditions

Example: particle size distribution for welding fumes are most abundant in the range of 0.1 – 2.5 µm

Source: Sowards et al (2008)


Direct Reading Instruments (DRIs)

Advantages

Real-time feedback of airborne particle behavior

Helpful for evaluating equipment operation and short-term tasks, lasting seconds to minutes

Disadvantages/Pitfalls

Non-specific, measure all particles present and that are within the operational range of the equipment

All potential interferences must be identified in order to properly interpret the results


Optical Particle Counters and Photometers

Optical particle counters (OPCs) measure particle size and number concentration by detecting the light scattered from individual particles

Photometers use conventional light-scattering technology to closely estimate particulate mass concentrations (mg/m3)


Condensation Particle Counter (CPC)

Condensation particle counters first enlarge very small particles to an optically detectable size

Concentration measured in particles per cubic centimeter air (particles/cm3)

They are used to count particles in size ranges that are invisible to OPCs and photometers

Good choice for measurement of ultrafine particles


DRIs - Photometer

Measures aerosol concentrations corresponding to PM1, PM2.5, Respirable, or PM10 size fractions

Aerosol concentration range 0.001 to 150 mg/m3

Manual and programmable data logging functions

DustTrak™ II Aerosol Monitor 8532 Photometer


DRIs – CPCs

Particle size range of 0.01 to >1.0 µm

Concentration range of 0 to 100,000 particles/cm3

Battery-powered operation

Programmable data-logging capabilities

TSI Model 3007

Condensation Particle Counter (CPC)


Comparison of CPC and OPC ranges


1.0 nm 10 nm 100 nm 300 nm 1.0 µm 10 µ

CPC OPC

• OPC and CPC share the same size range between ~300 nn and 1.0 µm

• The NIOSH NEAT Method describes how both DRIs can be used together to determine number concentrations of smaller versus larger sized particles

NIOSH REL = 1 μg/m3 Analytical Method: NIOSH Method 5040, Total Elemental Carbon

Mass Concentration Analysis

Issued: April, 2013


Filter-Based Microscopic Analysis

Tubular/Fibrous: • High Aspect Ratio

(e.g., Carbon Nanotubes) Irregular Shapes:

• Generally More Surface Area

Than Compact Particles (e.g., Iron Powders)


Evaluation Techniques


Example: Welding fume evaluation protocol Combining laboratory-based analysis and DRIs to develop an exposure metric for welding fumes

Welding Fumes: Key Points

Welding fumes are classified as ultrafine particles

Traditional filter sampling based on mass does not adequately define health risk

Fume particles are present in higher concentrations than smaller particles and are most abundant in the range of 0.1 to 2.5 micrometers (Sowards et al, 2008)

DRIs, such as CPCs, can be used to assess exposure during short tasks and effectiveness of controls


Evaluation Protocol: Welding Fumes

Identify all sources of ultrafine particles prior to sampling

Collect baseline sampling using desired DRI

Identify all sources of ventilation: local exhaust, and other natural/mechanical sources

Identify all hot work consumables and metal surfaces to be welded

Do side-by-side filter/elemental sampling along with DRI sampling



When sampling using a DRI, identify specific locations where sampling will occur, describing the distance from the source and worker.

Spot-sample at the welder’s breathing zone, under the welding helmet and outside of helmet. Do not sample under the respirator if one is being worn

Filter cassette should be placed inside welding helmet per OSHA Technical Manual: if respirator used (i.e.: hooded PAPR) collect outside respirator device



Review lab results, DRI welding and background DRI levels

Compare background levels with DRI concentrations collected during task (During task/Background) = DRI factor

Compare lab results with OEL (Level during task/OEL) = hazard factor

Correlate hazard factor with DRI factor

Goal: To be able to use DRI data alone to predict risk



Risk Level Matrix

If there is good correlation between hazard and DRI factors, a risk level matrix can be established

Consider defining risk as either low, medium, or high based on the hazard factor and corresponding DRI factor as follows:


Risk Level Hazard Factor DRI Factor*

Low ≤ 0.20 20x or less

Medium 0.20 – 0.40 20x - 30x

High >0.40 >30x

*These values can be adjusted based on field data results and professional judgment


• Assume stainless steel welding, hexavalent chromium, PEL = 5 µg/m3 and Background DRI = 10 µg/m3

• Risk Level could be assigned low, medium, or high, based on correlation with hazard factor


Lab result (µg/m3)

Hazard Factor

DRI data (µg/m3)

DRI Factor

Risk Level

1 0.20 100 10 Low

3 0.60 300 30 Medium

5 1.00 500 50 High

7 1.40 700 70 High

Note: All values in table are hypothetical

Summary and Conclusions

Implications

References

Resources


Implications

The promise of nanomaterials has similar parallels that were associated with the rise of asbestos in the first part of the 19th Century

The use of nanomaterials is rapidly increasing

Neither the occupational nor the non-occupational exposure risk is well understood


Implications

Actual or perceived risk from nanomaterials poses a potential litigation risk to organizations that are involved at all stages of the value chain, from R&D to end users


References

Giges, Nancy S. (2013): Top 5 Trends in Nanotechnology, ASME.org

Bowman, Robert (2014): Doctors Claim New Evidence That

Nanotechnology Can Make Workers Sick, Forbes.com

McCue, John (2013): My take: 2014 Outlook on Power & Utilities, Deloitte LLP

Sowards, J. W. et al (2008): Characterization of Welding Fume from

SMAW Electrodes - Part I. Welding Research, April 2008, Vol. 87, pp. 106-112.


Industrial Hygiene Resources Nanotechnology Health and Safety

Good NanoGuide, http://www.goodnanoguide.org/HomePage

Dimitri, J., Rickabaugh, K., Webb, P., Shepard, M. Industrial Hygiene Practices for Assessing Nanomaterials Exposures (Nov, 2013), AIHA The Synergist, AIHA, pp24-27

Join the AIHA Nanotechnology Working Group


http://www.goodnanoguide.org/HomePage

63

AIHA Nanotechnology Working Group (NTWG)

2014-2015 Leadership Team Chair – Jennifer Dimitri Vice Chair – Michele Shepard Secretary – Paul Webb Secretary-Elect – John Baker Past Chair – Candace Tsai AIHA Liaison– Thursa L. Pecoraro, [email protected]

Visit our webpage under Volunteer Groups @AIHA: www.aiha.org/insideaiha/volunteergroups/Pages/NTWG.aspx

Nano, IH, and the Electric Power Industry, Fall 2014 Conference

mailto:[email protected]

Questions?

For further information regarding this presentation, health risk assessments, or litigation support, contact:

Colden Corporation

Occupational and Environmental Health Science Group www.colden.com

Shannon Magari, ScD, MS, MPH

Paul J. Webb, MPH, MBA, CIH, CSP


http://www.colden.com/

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Nanotechnology, Industrial Hygiene, and the Electric Power Industry s/eeiFall2014/ih/webb.pdf · The Promise of Nanotechnology Nanotechnology will leave virtually no aspect of life