Category Archives: health and safety

No more kevlar-wrapped lithium-ion batteries?

Current lithium-ion batteries present a fire hazard, which is why, last, year a team of researchers at the University of Michigan came up with a plan to prevent fires by wrapping the batteries in kevlar. My Jan. 30, 2015 post describes the research and provides some information about airplane fires caused by the use of lithium-ion batteries.

This year, a team of researchers at Stanford University (US) have invented a lithium-ion (li-ion) battery that shuts itself down when it overheats, according to a Jan. 12, 2016 news item on Nanotechnology Now,

Stanford researchers have developed the first lithium-ion battery that shuts down before overheating, then restarts immediately when the temperature cools.

The new technology could prevent the kind of fires that have prompted recalls and bans on a wide range of battery-powered devices, from recliners and computers to navigation systems and hoverboards [and on airplanes].

“People have tried different strategies to solve the problem of accidental fires in lithium-ion batteries,” said Zhenan Bao, a professor of chemical engineering at Stanford. “We’ve designed the first battery that can be shut down and revived over repeated heating and cooling cycles without compromising performance.”

Stanford has produced a video of Dr. Bao discussing her latest work,

A Jan. 11, 2016 Stanford University news release by Mark Schwartz, which originated the news item, provides more detail about li-ion batteries and the new fire prevention technology,

A typical lithium-ion battery consists of two electrodes and a liquid or gel electrolyte that carries charged particles between them. Puncturing, shorting or overcharging the battery generates heat. If the temperature reaches about 300 degrees Fahrenheit (150 degrees Celsius), the electrolyte could catch fire and trigger an explosion.

Several techniques have been used to prevent battery fires, such as adding flame retardants to the electrolyte. In 2014, Stanford engineer Yi Cui created a “smart” battery that provides ample warning before it gets too hot.

“Unfortunately, these techniques are irreversible, so the battery is no longer functional after it overheats,” said study co-author Cui, an associate professor of materials science and engineering and of photon science. “Clearly, in spite of the many efforts made thus far, battery safety remains an important concern and requires a new approach.”


To address the problem Cui, Bao and postdoctoral scholar Zheng Chen turned to nanotechnology. Bao recently invented a wearable sensor to monitor human body temperature. The sensor is made of a plastic material embedded with tiny particles of nickel with nanoscale spikes protruding from their surface.

For the battery experiment, the researchers coated the spiky nickel particles with graphene, an atom-thick layer of carbon, and embedded the particles in a thin film of elastic polyethylene.

“We attached the polyethylene film to one of the battery electrodes so that an electric current could flow through it,” said Chen, lead author of the study. “To conduct electricity, the spiky particles have to physically touch one another. But during thermal expansion, polyethylene stretches. That causes the particles to spread apart, making the film nonconductive so that electricity can no longer flow through the battery.”

When the researchers heated the battery above 160 F (70 C), the polyethylene film quickly expanded like a balloon, causing the spiky particles to separate and the battery to shut down. But when the temperature dropped back down to 160 F (70 C), the polyethylene shrunk, the particles came back into contact, and the battery started generating electricity again.

“We can even tune the temperature higher or lower depending on how many particles we put in or what type of polymer materials we choose,” said Bao, who is also a professor, by courtesy, of chemistry and of materials science and engineering. “For example, we might want the battery to shut down at 50 C or 100 C.”

Reversible strategy

To test the stability of new material, the researchers repeatedly applied heat to the battery with a hot-air gun. Each time, the battery shut down when it got too hot and quickly resumed operating when the temperature cooled.

“Compared with previous approaches, our design provides a reliable, fast, reversible strategy that can achieve both high battery performance and improved safety,” Cui said. “This strategy holds great promise for practical battery applications.”

Here’s a link to and a citation for the paper,

Fast and reversible thermoresponsive polymer switching materials for safer batteries by Zheng Chen, Po-Chun Hsu, Jeffrey Lopez, Yuzhang Li, John W. F. To, Nan Liu, Chao Wang, Sean C. Andrews, Jia Liu, Yi Cui, & Zhenan Bao. Nature Energy 1, Article number: 15009 (2016) doi:10.1038/nenergy.2015.9 Published online: 11 January 2016

This paper appears to be open access.

Waterless, stinkfree toilets thanks to nanotechnology

A Jan. 7, 2016 article by Magda Mis for the Thomson Reuters Foundation focuses on an innovative approach to waste management (toilets) taken by researchers at Cranfield University (UK),

A toilet that does not need water, a sewage system or external power but instead uses nanotechnology to treat human waste, produce clean water and keep smells at bay is being developed by a British university.

The innovative toilet uses a rotating mechanism to move waste into a holding chamber containing nano elements. The mechanism also blocks odours and keeps waste out of sight.

“Once the waste is in the holding chamber we use membranes that take water out as vapour, which can then be condensed and available for people to use in their homes,” Alison Parker, lead researcher on the project, told the Thomson Reuters Foundation.

“The pathogens remain in the waste at the bottom of the holding chamber, so the water is basically pure and clean.”

It’s known as the (Cranfield) Nano Membrane Toilet (website here),

I winced a bit watching that as would, I imagine, any number of people living in one of Britain’s former colonies (Canada, India, Ghana, Nigeria, Jamaica, New Zealand, and others in what’s now known as the Commonwealth countries).

Getting back to the article, Cranfield participated in a Gates Foundation competition and won a grant to develop this toilet,

Cranfield University is developing the toilet as part of the global “Reinvent the toilet Challenge” launched by the Bill and Melinda Gates Foundation.

Parker said that despite “significant” interest from developed countries, the toilet is being designed with those in mind who have no access to adequate toilets.

Poor sanitation is linked to transmission of diseases such as cholera, diarrhoea, dysentery, hepatitis A, typhoid and polio, the WHO [World Health Organization] says.

Cranfield University says its toilet is designed for a household of up to 10 people and will cost just $0.05 per day per user.


Québec’s second edition of its Best Practices Guidance for Nanomaterial Risk Management in the Workplace

Lynn Bergeson’s Dec. 16, 2015 posting on Nanotechnology Now highlights Québec’s second edition of its guide to best practices for handling nanomaterials in the workplace,

On December 11, 2015, the Institut de recherche Robert-Sauvé en santé et en sécurité du travail (IRSST), a leading occupational health and safety research center in Canada, published the second edition of its Best Practices Guidance for Nanomaterial Risk Management in the Workplace.

… IRSST intends the Guidance to support the safe development of nanotechnologies in Québec by bringing together current scientific knowledge on hazard identification, strategies for determining nanomaterial levels in different work environments, risk assessment, and the application of various risk management approaches. IRSST states that the Guidance provides practical information and prevention tools for the safe handling of nanomaterials in laboratories and pilot plants, as well as industrial facilities that produce or incorporate them. The Guidance recommends a preventive approach designed to minimize occupational exposure to nanomaterials. According to IRSST, given the different exposure pathways, the many factors that can affect nanomaterial toxicity and the health risks, its approach “is essentially based on hazard identification, different risk assessment strategies and a hierarchy of control measures, incorporating knowledge specific to nanomaterials when available.” The second edition of the Guidance incorporates new information in the scientific literature. In addition, IRSST has included appendices describing initiatives in Québec workplaces; examples of at-risk situations described in the literature; preventive measures and data on their relative efficacy; and the implementation of measures to control exposure. ,,,

The Best Practices Guidance for Nanomaterial Risk Management in the Workplace can be found here on the IRSST website where you’ll also find this description,

Today’s nanotechnologies can substantially improve the properties of a wide range of products in all sectors of activity, from the manufacture of materials with ground-breaking performance to medical diagnostics and treatment—yet they raise major technological, economic, ethical, social and environmental questions. Some of the spinoffs we can expect include the emergence of new markets, job creation, improvements in quality of life and contributions to protection of the environment. The impact of nanotechnologies is already being felt in sectors as diverse as agroprocessing, cosmetics, construction, healthcare and the aerospace industry. Most universities in Québec and many research centres are working to design new applications. Many companies have projects in the start-up phase, while others are already producing nanomaterials or have incorporated them in their processes to improve product performance, a trend expected to accelerate over the coming years. These new developments, which could mean exposure of a growing number of workers to these infinitesimally small particles, are of particular concern to workers in industry and staff in research laboratories. It is estimated that in 2015 about 10% of manufacturing jobs worldwide will be associated with nanotechnologies, [emphasis mine] and more than 2,000 commercial products will contain nanomaterials.

Given our fragmentary knowledge of the health and safety risks for workers and the environment, the handling of these new materials with their unique properties raises many questions and concerns. In fact, many studies have already demonstrated that the toxicity of certain nanomaterials differs from that of their bulk counterparts of the same chemical composition. Nanomaterials enter the body mainly through inhalation but also through the skin and the GI tract. Animal studies have demonstrated that certain nanomaterials can enter the blood stream through translocation and accumulate in different organs. Animal studies also show that certain nanomaterials cause more inflammation and more lung tumours on a mass-for-mass basis than the same substances in bulk form, among many other specific effects documented. In addition, research has shown that the physicochemical characteristics of nanomaterials (size, shape, specific surface area, charge, solubility and surface properties) play a major role in their impact on biological systems, including their ability to generate oxidative stress. It is thus crucial that risks be assessed and controlled to ensure the safe handling of nanomaterials. As with many other chemicals, a risk assessment and management approach must be developed on a case-by-case basis.

There is still no consensus, however, on a measurement method for characterizing occupational exposure to nanomaterials, making quantitative risk assessment difficult if not impossible in many situations. As a result, a precautionary approach is recommended to minimize worker exposure. In Québec, the employer is responsible for providing a safe work environment, and preventive measures must be applied by employees. Accordingly, preventive programs that take into account the specific characteristics of nanomaterials must be developed in all work environments where nanomaterials are handled, so that good work practices can be established and preventive procedures tailored to the risks of the particular work situation can be introduced.

Fortunately, current scientific knowledge, though partial, makes it possible to identify, assess and effectively manage these risks. This best practices guide is meant to support the safe development of nanotechnologies in Québec by bringing together current scientific knowledge on hazard identification, strategies for determining nanomaterial levels in different work environments, risk assessment and the application of various risk management approaches. Some knowledge of occupational hygiene is required to use this guide effectively. Designed for all work environments that manufacture or use nanomaterials, this guide provides practical information and prevention tools for the safe handling of nanomaterials in laboratories and pilot plants as well as industrial facilities that produce or incorporate them. To be effective, risk management must be an integral part of an organization’s culture, and health and safety issues must be considered when designing the workplace or as far upstream as possible. This is crucial for good organizational governance. In practice, risk management is an iterative process implemented as part of a structured approach that fosters continuous improvement in decision-making and can even promote better performance. The purpose of this guide is to contribute to the implementation of such an approach to the prevention of nanomaterial-related risks only. Depending on the process, other risks (associated with exposure to solvents, gas, heat stress, ergonomic stress, etc.) may be present, but they are not addressed in this guide.

I wonder where they got these numbers, “It is estimated that in 2015 about 10% of manufacturing jobs worldwide will be associated with nanotechnologies, and more than 2,000 commercial products will contain nanomaterials.” Given that many companies don’t like to disclose whether or not they’re using nanomaterials and most countries don’t insist on an inventory (there are voluntary inventories, which generally speaking have not been successful), bringing me back to the question: where did these numbers come from?

As for the guide itself, Canadians have been very involved with the OECD (Organization for Economic Cooperation and Development) and its ‘nanomaterial safety’ working group and, I understand, have provided leadership on occasion. The guide, which is available in both French and English, is definitely worth checking out.

Finding a way to prevent sunscreens from penetrating the skin

While nanosunscreens have been singled out for their possible impact on our health, the fact is many sunscreens contain dangerous ingredients penetrating the skin. A Dec. 14, 2015 news item on ScienceDaily describes some research into getting sunscreens to stay on the skin surface avoiding penetration,

A new sunscreen has been developed that encapsulates the UV-blocking compounds inside bio-adhesive nanoparticles, which adhere to the skin well, but do not penetrate beyond the skin’s surface. These properties resulted in highly effective UV protection in a mouse model, without the adverse effects observed with commercial sunscreens, including penetration into the bloodstream and generation of reactive oxygen species, which can damage DNA and lead to cancer.

A US National Institute of Biomedical Imaging and Bioengineering (NIBIB) Dec. 14, 2015 news release, which originated the news item, expands on the theme (Note: Links have been removed),

Commercial sunscreens use compounds that effectively filter out damaging UV light. However, there is concern that these agents have a variety of harmful effects due to penetration past the surface skin. For example, these products have been found in human breast tissue and urine and are known to disrupt the normal function of some hormones. Also, the exposure of the UV filters to light can produce toxic reactive oxygen species that are destructive to cells and tissues and can cause tumors through DNA damage.

“This work applies a novel bioengineering idea to a little known but significant health problem, adds Jessica Tucker, Ph.D., Director of the NIBIB Program in Delivery Systems and Devices for Drugs and Biologics. “While we are all familiar with the benefits of sunscreen, the potential toxicities from sunscreen due to penetration into the body and creation of DNA-damaging agents are not well known. Bioengineering sunscreen to inhibit penetration and keep any DNA-damaging compounds isolated in the nanoparticle and away from the skin is a great example of how a sophisticated technology can be used to solve a problem affecting the health of millions of people.”

Bioengineers and dermatologists at Yale University in New Haven, Connecticut combined their expertise in nanoparticle-based drug delivery and the molecular and cellular characteristics of the skin to address these potential health hazards of current commercial sunscreens.

The news release then goes on to provide some technical details,

The group encapsulated a commonly used sunscreen, padimate O (PO), inside a nanoparticle (a very small molecule often used to transport drugs and other agents into the body). PO is related to the better-known sunscreen PABA.

The bioadhesive nanoparticle containing the sunscreen PO was tested on pigs for penetration into the skin. A control group of pigs received the PO alone, not encapsulated in a nanoparticle. The PO penetrated beyond the surface layers of skin where it could potentially enter the bloodstream through blood vessels that are in the deeper skin layers. However, the PO inside the nanoparticle remained on the surface of the skin and did not penetrate into deeper layers.

Because the bioadhesive nanoparticles, or BNPs are larger than skin pores it was somewhat expected that they could not enter the body by that route. However, skin is full of hair follicles that are larger than BNPs and so could be a way for migration into the body. Surprisingly, BNPs did not pass through the hair follicle openings either. Tests indicated that the adhesive properties of the BNPs caused them to stick to the skin surface, unable to move through the hair follicles.

Further testing showed that the BNPs were water resistant and remained on the skin for a day or more, yet were easily removed by towel wiping. They also disappeared in several days through natural exfoliation of the surface skin.

BNPs enhance the effect of sunscreen

An important test was whether the BNP-encapsulated sunscreen retained its UV filtering properties. The researchers used a mouse model to test whether PO blocked sunburn when encapsulated in the BNPs. The BNP formulation successfully provided the same amount of UV protection as the commercial products applied directly to the skin of the hairless mouse model. Surprisingly, this was achieved even though the BNPs carried only a fraction (5%) of the amount of commercial sunblock applied to the mice.

Finally, the encapsulated sunscreen was tested for the formation of damaging oxygen-carrying molecules known as reactive oxygen species, (ROS) when exposed to UV light. The researchers hypothesized that any ROS created by the sunscreen’s interaction with UV would stay contained inside the BNP, unable to damage surrounding tissue. Following exposure to UV light, no damaging ROS were detected outside of the nanoparticle, indicating that any harmful agents that were formed remained inside of the nanoparticle, unable to make contact with the skin.

“We are extremely pleased with the properties and performance of our BNP formulation,” says senior author Mark Saltzman, Ph.D., Yale School of Engineering and Applied Science. “The sunscreen loaded BNPs combine the best properties of an effective sunscreen with a safety profile that alleviates the potential toxicities of the actual sunscreen product because it is encapsulated and literally never touches the skin.” Adds co-senior author, Michael Girardi, M.D. “Our nanoparticles performed as expected, however, these are preclinical findings. We are now in a position to assess the effects on human skin.”

So, all of this work has been done on animal models, which means that human clinical trials are the likely next step. As we wait, here’s a link to and a citation for this group’s paper,

A sunblock based on bioadhesive nanoparticles by Yang Deng, Asiri Ediriwickrema, Fan Yang, Julia Lewis, Michael Girardi, & W. Mark Saltzman. Nature Materials 14, 1278–1285 (2015) doi:10.1038/nmat4422 Published online 28 September 2015

This paper is behind a paywall.

You gotta shake, shake, shake those nanomaterials out of the water

A team at Michigan Technological University (Michigan Tech) has developed a simple technique for clearing nanoparticles from water according to a Dec. 10, 2015 news item on Nanotechnology Now,

Nano implies small—and that’s great for use in medical devices, beauty products and smartphones—but it’s also a problem. The tiny nanoparticles, nanowires, nanotubes and other nanomaterials that make up our technology eventually find their way into water. The Environmental Protection Agency says more 1,300 commercial products use some kind of nanomaterial. And we just don’t know the full impact on health and the environment.

A Dec. 10, 2015 Michigan Tech news release, which originated the news item, describes the concept and the research in more detail,

“Look at plastic,” says Yoke Khin Yap, a professor of physics at Michigan Technological University. “These materials changed the world over the past decades—but can we clean up all the plastic in the ocean? We struggle to clean up meter-scale plastics, so what happens when we need to clean on the nano-scale?”

The method sounds like a salad dressing recipe: take water, sprinkle in nanomaterials, add oil and shake.

Water and oil don’t mix, of course, but shaking them together is what makes salad dressing so great. Only instead of emulsifying and capturing bits of shitake or basil in tiny olive oil bubbles, this mixture grabs nanomaterials.

Dongyan Zhang, a research professor of physics at Michigan Tech, led the experiments, which covered tests on carbon nanotubes, graphene, boron nitride nanotubes, boron nitride nanosheets and zinc oxide nanowires. Those are used in everything from carbon fiber golf clubs to sunscreen.

“These materials are very, very tiny, and that means if you try to remove them and clean them out of contaminated water, that it’s quite difficult,” Zhang says, adding that techniques like filter paper or meshes often don’t work.

What makes shaking work is the shape of one- and two-dimensional nanomaterials. As the oil and water separate after some rigorous shaking, the wires, tubes and sheets settle at the bottom of the oil, just above the water. The oils trap them. However, zero-dimensional nanomaterials, such as nanospheres do not get trapped.

The researchers, according to the news release, are attempting to anticipate the potential contamination of our water supply by nanomaterials and provide a solution before it happens,

We don’t have to wait until the final vote is in on whether nanomaterials have a positive or negative impact on people’s health and environmental health. With the simplicity of this technique, and how prolific nanomaterials are becoming, removing nanomaterials makes sense. Also, finding ways to effectively remove nanomaterials sooner rather than later could improve the technology’s market potential.

“Ideally for a new technology to be successfully implemented, it needs to be shown that the technology does not cause adverse effects to the environment,” Yap, Zhang and their co-authors write. “Therefore, unless the potential risks of introducing nanomaterials into the environment are properly addressed, it will hinder the industrialization of products incorporating nanotechnology.”

Purifying water and greening nanotechnology could be as simple as shaking a vial of water and oil.

Here’s a video about the research supplied by Michigan Tech,

Here’s a link to and a citation for the paper,

A Simple and Universal Technique To Extract One- and Two-Dimensional Nanomaterials from Contaminated Water by Bishnu Tiwari, Dongyan Zhang, Dustin Winslow, Chee Huei Lee, Boyi Hao, and Yoke Khin Yap. ACS Appl. Mater. Interfaces, 2015, 7 (47), pp 26108–26116 DOI: 10.1021/acsami.5b07542 Publication Date (Web): November 9, 2015

Copyright © 2015 American Chemical Society

This paper is behind a paywall.

A wearable, stretchable body sensor based on chewing gum and carbon nanotubes

Any work which features a scientist chewing gum preparatory to using it for research purposes should be widely disseminated. In all the talk about science and equipment, it’s easy to forget that scientists are capable of great ingenuity with simple, every day materials. Also, the researchers are Canadian and based at the University of Manitoba. From a Dec. 2, 2015 American Chemical Society (ACS) news release (also on EurekAlert),

Body sensors, which were once restricted to doctors’ offices, have come a long way. They now allow any wearer to easily track heart rate, steps and sleep cycles around the clock. Soon, they could become even more versatile — with the help of chewing gum. Scientists report in the journal ACS Applied Materials & Interfaces a unique sensing device made of gum and carbon nanotubes that can move with your most bendable parts and track your breathing.

Most conventional sensors today are very sensitive and detect the slightest movement, but many are made out of metal. That means when they’re twisted or pulled too much, they stop working. But for sensors to monitor the full range of a body’s bending and stretching, they need a lot more give. To meet that need, some researchers have tried developing sensors using stretchy plastics and silicones. But what they gained in flexibility, they lost in sensitivity. Malcolm Xing and colleagues found a better solution right under their noses — and in their mouths.

To make their supple sensor, a team member chewed a typical piece of gum for 30 minutes, washed it with ethanol and let it sit overnight. The researchers then added a solution of carbon nanotubes, the sensing material. Simple pulling and folding coaxed the tubes to align properly. Human finger-bending and head-turning tests showed the material could keep working with high sensitivity even when strained 530 percent. The sensor also could detect humidity changes, a feature that could be used to track breathing, which releases water vapor with every exhale.

Here’s a link to and a citation for the paper,

Gum Sensor: A Stretchable, Wearable, and Foldable Sensor Based on Carbon Nanotube/Chewing Gum Membrane by Mohammad Ali Darabi, Ali Khosrozadeh, Quan Wang, and Malcolm Xing. ACS Appl. Mater. Interfaces, 2015, 7 (47), pp 26195–26205 DOI: 10.1021/acsami.5b08276 Publication Date (Web): November 2, 2015

Copyright © 2015 American Chemical Society

This paper is behind a paywall.

This video lets you see the gum/CNT material at work,


A couple of lawyers talk wrote about managing nanotechnology risks

Because they are lawyers, I was intrigued by a Nov. 4, 2015 article on managing nanotechnology risks by Michael Lisak and James Mizgala of Sidley Austin LLP for Industry Week. I was also intrigued by the language (Note: A link has been removed),

The inclusion of nanotechnologies within manufacturing processes and products has increased exponentially over the past decade. Fortune recently noted that nanotechnology touches almost all Fortune 500 companies and that the industry’s $20 billion worldwide size is expected to double over the next decade. [emphasis mine]

Yet, potential safety issues have been raised and regulatory uncertainties persist. As such, proactive manufacturers seeking to protect their employees, consumers, the environment and their businesses – while continuing to develop, manufacture and market their products – may face difficult choices in how to best navigate this challenging and fluid landscape, while avoiding potential “nanotort,”  [emphasis mine] whistleblower, consumer fraud and regulatory enforcement lawsuits. Doing so requires forward-thinking advice based upon detailed analyses of each manufacturer’s products and conduct in the context of rapidly evolving scientific, regulatory and legal developments.

I wonder how many terms lawyers are going to coin in addition to “nanotort”?

The lawyers focus largely on two types of nanoparticles, carbon nanotubes, with a special emphasis on multi-walled carbon nantubes (MWCNT) and nano titanium dioxide,

Despite this scientific uncertainty, international organizations, such as the International Agency for Research on Cancer [a World Health Organization agency], have already concluded that nano titanium dioxide in its powder form and multi-walled carbon nanotube-7 (“MWCNT-7”) [emphasis mine] are “possibly carcinogenic to humans.” As such, California’s Department of Public Health lists titanium dioxide and MWCNT-7 as “ingredients known or suspected to cause cancer, birth defects, or other reproductive toxicity as determined by the authoritative scientific bodies.”  Considering that processed (i.e., non-powdered) titanium dioxide is found in products like toothpaste, shampoo, chewing gum and candies, it is not surprising that some have focused upon such statements.

There’s a lot of poison in the world, for example, apples contain seeds which have arsenic in them and, for another, peanuts can be carcinogenic and they can also kill you, as they are poison to people who are allergic to them.

On the occasion of Dunkin’ Donuts removing nano titanium dioxide as an ingredient in the powdered sugar used to coat donuts, I wrote a March 13, 2015 posting, where I quote extensively from Dr. Andrew Maynard’s (then director of the University of Michigan Risk Science Center now director of the Risk Innovation Lab at Arizona State University) 2020 science blog posting about nano titanium dioxide and Dunkin’ Donuts,

He describes some of the research on nano titanium dioxide (Note: Links have been removed),

… In 2004 the European Food Safety Agency carried out a comprehensive safety review of the material. After considering the available evidence on the same materials that are currently being used in products like Dunkin’ Donuts, the review panel concluded that there no evidence for safety concerns.

Most research on titanium dioxide nanoparticles has been carried out on ones that are inhaled, not ones we eat. Yet nanoparticles in the gut are a very different proposition to those that are breathed in.

Studies into the impacts of ingested nanoparticles are still in their infancy, and more research is definitely needed. Early indications are that the gastrointestinal tract is pretty good at handling small quantities of these fine particles. This stands to reason given the naturally occurring nanoparticles we inadvertently eat every day, from charred foods and soil residue on veggies and salad, to more esoteric products such as clay-baked potatoes. There’s even evidence that nanoparticles occur naturally inside the gastrointestinal tract.

You can find Andrew’s entire discussion in his March 12, 2015 post on the 2020 Science blog. Andrew had written earlier in a July 12, 2014 posting about something he terms ‘nano donut math’ as reported by As You Sow, the activist group that made a Dunkin’ Donuts shareholder proposal which resulted in the company’s decision to stop using nano titanium dioxide in the powdered sugar found on their donuts. In any event, Andrew made this point,

In other words, if a Dunkin’ Donut Powdered Cake Donut contained 8.9 mg of TiO2 particles smaller than 10 nm, it would have to have been doused with over 1 million tons of sugar coating! (Note update at the end of this piece)

Clearly something’s wrong here – either Dunkin’ Donuts are not using food grade TiO2 but a nanopowder with particle so small they would be no use whatsoever in the sugar coating (as well as being incredibly expensive, and not FDA approved).  Or there’s something rather wrong with the analysis!

If it’s the latter – and it’s hard to imagine any other plausible reason for the data – it looks like As You Sow ended up using rather dubious figures to back up their stakeholder resolution.  I’d certainly be interested in more information on the procedures Analytical Sciences used and the checks and balances they had in place, especially as there are a number of things that can mess up a particle analysis like this.

Update July 14: My bad, I made a slight error in the size distribution calculation first time round.  This has been corrected in the article above.  Originally, I cited the estimated Mass Median Diameter (MMD) of the TiO2 particles as 167 nm, and the Geometric Standard Deviation (GSD) as 1.6.  Correcting an error in the Excel spreadsheet used to calculate the distribution (these things happen!) led to a revised estimate of MMD = 168 nm and a GSD of 1.44.  These may look like subtle differences, but when calculating the estimated particle mass below 10 nm, they make a massive difference.  With the revised figures, you’d expect less than one trillionth of  a percent of the mass of the TiO2 powder to be below 10 nm!! (the original estimate was a tenth of a millionth of a percent).  In other words – pretty much nothing!  The full analysis can be found here.

Update November 16 2014.  Based on this post, As You Sow checked the data from Analytical Sciences LLC and revised the report accordingly.  This is noted above.

It would seem that if there are concerns over nano titanium dioxide in food, the biggest would not be the amounts ingested by consumers but inhalation by workers should they breathe in large quantities when they are handling the material.

As for the MWCNTs, they have long raised alarms but most especially the long MWCNTs and for people handling them during the course of their work day. Any MWCNTs found in sports equipment and other consumer products are bound in the material and don’t pose any danger of being inhaled into the lungs, unless they should be released from their bound state (e.g. fire might release them).

After some searching for MWCNT-7, I found something which seems also to be known as Mitsui MWCNT-7 or Mitsui 7-MWCNT (here’s one of my sources). As best I understand it, Mitsui is a company that produces an MWCNT which they have coined an MWCNT-7 and which has been used in nanotoxicity testing. As best I can tell, MWCNT is MWCNT-7.

The lawyers (Lisak and Mizgala) note things have changed for manufacturers since the early days and they make some suggestions,

One thing is certain – gone are the days when “sophisticated” manufacturers incorporating nanotechnologies within their products can reasonably expect to shield themselves by pointing to scientific and regulatory uncertainties, especially given the amount of money they are spending on research and development, as well as sales and marketing efforts.

Accordingly, manufacturers should consider undertaking meaningful risk management analyses specific to their applicable products. …

First, manufacturers should fully understand the life-cycle of nanomaterials within their organization. For some, nanomaterials may be an explicit focus of innovation and production, making it easier to pinpoint where nanotechnology fits into their processes and products. For others, nanomaterials may exist either higher-up or in the back-end of their products’ supply chain. …

Second, manufacturers should understand and stay current with the scientific state-of-the-art as well as regulatory requirements and developments potentially applicable to their employees, consumers and the environment. An important consideration related to efforts to understand the state-of-the-art is whether or not manufacturers should themselves expend resources to advance “the science” in seeking to help find answers to some of the aforementioned uncertainties. …

The lawyers go on to suggest that manufacturers should consider proactively researching nanotoxicity so as to better defend themselves against any future legal suits.

Encouraging companies to proactive with toxicity issues is in line with what seems to be an international (Europe & US) regulatory movement putting more onus on producers and manufacturers to take responsibility for safety testing. (This was communicated to me in a conversation I had with an official at the European Union Joint Research Centre where he mentioned REACH regulations and the new emphasis in response to my mention of similar FDA (US Food and Drug Administration) regulations. (We were at the 2014 9th World Congress on Alternatives to Animal Testing in Prague, Czech republic.)

For anyone interested in the International Agency for Research on Cancer you can find it here.

‘Nano to go’, a practical guide to safe handling of nanomaterials and other innovative materials in the workplace

If you’ve been looking for a practical guide to handling nanomaterials you may find that nanoToGo fills the bill. From an Oct. 23, 2015 posting by Lynn Bergeson for Nanotechnology Now,

In September 2015, “Nano to go!” was published. See “Nano to go!” is “a practically oriented guidance on safe handling of nanomaterials and other innovative materials at the workplace.” The German Federal Institute for Occupational Health (BAuA) developed it within the NanoValid project.

From the nanoToGo webpage on the NanoValid project website (Note: Links have been removed),

Nano to go! contains a brochure, field studies, presentations and general documents to comprehensively support risk assessment and risk management. …

Brochure →

The brochure Safe handling of nanomaterials and other advanced materials at workplacessupports risk assessment and risk management when working with nanomaterials. It provides safety strategies and protection measures for handling nanomaterials bound in solid matrices, dissolved in liquids, insoluble or insoluble powder form, and for handling nanofibres. Additional recommendations are given for storage and disposal of nanomaterials, for protection from fire and explosion, for training and instruction courses, and for occupational health.

Field Studies→

The field studies comprise practical examples of expert assessment of safety and health at different workplaces. They contain detailed descriptions of several exposure measurements at pilot plants and laboratories. The reports describe methods, sampling strategies and devices, summarise and discuss results, and combine measurements and non-measurement methods.

General →

Useful information, templates and examples, such as operating instructions, a sampling protocol, a dialogue guide and a short introduction to safety management and nanomaterials.

Presentations →

Ready to use presentations for university lecturers, supervisors and instruction courses, complemented with explanatory notes.

The ‘brochure’ is 56 pages; I would have called it a manual.

As for the NanoValid project, there’s this from the project’s homepage,

The EU FP7 [Framework Programme 7] large-scale integrating project NanoValid (contract: 263147) has been launched on the 1st of November 2011, as one of the “flagship” nanosafety projects. The project consists of 24 European partners from 14 different countries and 6 partners from Brazil, Canada, India and the US and will run from 2011 to 2015, with a total budget of more than 13 mio EUR (EC contribution 9.6 mio EUR). Main objective of NanoValid is to develop a set of reliable reference methods and materials for the fabrication, physicochemical (pc) characterization, hazard identification and exposure assessment of engineered nanomaterials (EN), including methods for dispersion control and labelling of ENs. Based on newly established reference methods, current approaches and strategies for risk and life cycle assessment will be improved, modified and further developed, and their feasibility assessed by means of practical case studies.

I was not expecting to see Canada in there.

Nanotechnology-enabled full suit body protection against viral, biological, and chemical threats

Demron ICE: the world's first full-body suit that protects against viral, biological and chemical threats. Courtesy: Radiation Shield Technologies

Demron ICE: the world’s first full-body suit that protects against viral, biological and chemical threats. Courtesy: Radiation Shield Technologies

I liked it better when I thought the suit was called Demon ICE but it’s real name is Demron ICE and it’s being introduced at a trade show on the day before Hallowe’en 2015 according to an Oct. 28, 2015 news item on Azonano,

Radiation Shield Technologies, a global developer of advanced personal-protection gear, today announced its introduction of Demron ICE: the world’s first full-body suit that protects against viral, biological and chemical threats using a patented self-cooling fabric that is ASTM F1671 Blood and Viral Penetration Resistance certified.

The suit will be unveiled and exhibited Tuesday through Friday at the 8th Annual CBRNe [Chemical, Biological, Radiological, Nuclear, and high yield Explosives] Convergence Congress & Exhibition in Orlando, Fla. Specifically, the suit will be exhibited at the RST Booth No. 112, where live radiation testing of the company’s patented technologies will also take place.

An Oct. 27, 2015 Radiation Shield Technologies (RST) press release on BusinessWire, which originated the news item, provides more details about the presentation,

With a focus on promoting industry collaboration and preparedness for all hazard threats, the conference is considered the most important annual event for the global CBRNe community. Planned by the editor of CBRNe World magazine, the program unites top regional and international military and civil expert speakers providing shortcuts to best practice. Discussion topics will cover the latest hot-button issues, including responding to everything from nuclear threats to the Ebola virus. Ronald DeMeo, MD, president and CEO of RST, will provide a presentation on “Nuclear Countermeasures” at noon Thursday at “Stream H.” The presentation will explore varied topics including:

  • Preparing for CBRNe threats
  • Multi-hazard protection available today
  • Military first responders: the first line of defense
  • Military partners: case studies and examples

A key component of the presentation will focus on the increased need for advanced solutions such as Demron ICE, which is differentiated from others on the market by its proven ability to enable the longest extended use with the lowest degree of heat stress. The gear, available at, is made with the Demron fabric and includes booties, gloves and a face seal.

The press release also provides an explanation for why this new suit was developed without  explaining how this is a nanotechnology-enabled product,

“We developed Demron ICE in response to a growing global demand from healthcare workers, members of the military and other first responders for a comfortable full-body suit that provides protection against viral, biological, and chemical threats and may be comfortably worn for prolonged periods of time with significantly less heat stress than other gear on the market,” said Ronald DeMeo, M.D., MBA, president of RST and the surgeon who invented Demron.

Here’s how other CBRN suits work: When first responders wear the CBRN suits, their body heat is quickly trapped in the suits, causing the users to become increasingly weak until they are incapacitated. Because the suits are designed to keep chemical agents from entering, they also keep heat from exiting. However, Demron ICE is differentiated by its unique thermally conductive properties that enable heat to leave the suits through thermal radiation and also enable the suits to be cooled externally without compromising the suits.

“With Demron ICE, first responders can operate in the field longer and safer than ever before,” Dr. DeMeo said. “As a global leader in advanced personal protection gear, Radiation Shield Technologies will continue to innovate and introduce new products to keep pace with increased threats from an ever-changing enemy in today’s uncertain world.”

Demron ICE, which exceeds the latest Centers for Disease Control guidelines, is the most thermally conductive impermeable suit on the market today. Demron ICE’s self-cooling system also makes it possible to provide external cooling with ice packs or wet towels and to monitor the user’s body temperature without having to remove or penetrate the suit. The Demron ICE material also is differentiated for its superior flexibility, ruggedness, durability, and ability to withstand tearing, extensive use, and decontamination procedures and corrosive agents.

Certifications include: ASTM F1670, ASTM F1671 Blood and Viral Penetration. Resistance: NFPA 1994/2007 for Chem/Bio (2012 pending), ISO 8194 Certified: Radiation Protective Clothing, ISO 9001 Certified: Quality Management.

Demron ICE is part of the Demron product line, which also includes a series of full-body suits, vests, blankets and medical X-ray vests and aprons that provide chemical, biological, radiation and heat-stress protection. Demron, which has many U.S. and international patents, consists of an advanced radiopaque nanopolymeric compound [emphasis mine] fused between layers of fabric to manufacture the personal-protection gear.

Demron products are currently deployed worldwide by every branch of the U.S. military, U.S. CST teams, FDNY, IAEC, NASA, and many international first responder and military teams in China, Iraq, Kuwait, South Korea, Pakistan, UAE, Saudi Arabia, Vietnam, and Singapore. Scientists have selected Demron for thermo-mechanical suits for future space travel. RST manufactures Demron and the nano materials at its research and development facility in Miami.

The Radiation Shield Technologies website can be found here.

Inadvertent carbon nanotube production from your car

It’s disconcerting to find out that cars inadvertently produce carbon nanotubes which are then spilled into the air we breathe. Researchers at Rice University (US) and Paris-Saclay University (France) have examined matter from car exhausts and dust in various parts of Paris finding carbon nanotubes (CNTs). Further, they also studied the lungs of Parisian children who have asthma and found CNTs there too.

The scientists have carefully stated that CNTs have been observed in lung cells but they are not claiming causality (i.e., they don’t claim the children’s asthma was caused by CNTs).

An Oct. 20, 2015 news item on Nanotechnology Now introduces the research,

Cars appear to produce carbon nanotubes, and some of the evidence has been found in human lungs.

Rice University scientists working with colleagues in France have detected the presence of man-made carbon nanotubes in cells extracted from the airways of Parisian children under routine treatment for asthma. Further investigation found similar nanotubes in samples from the exhaust pipes of Paris vehicles and in dust gathered from various places around the city.

The researchers reported in the journal EBioMedicine this month that these samples align with what has been found elsewhere, including Rice’s home city of Houston, in spider webs in India and in ice cores.

An Oct. 19, 2015 Rice University news release (also on EurekAlert), which originated the news item, painstakingly describes the work and initial conclusions,

The research in no way ascribes the children’s conditions to the nanotubes, said Rice chemist Lon Wilson, a corresponding author of the new paper. But the nanotubes’ apparent ubiquity should be the focus of further investigation, he said.

“We know that carbon nanoparticles are found in nature,” Wilson said, noting that round fullerene molecules like those discovered at Rice are commonly produced by volcanoes, forest fires and other combustion of carbon materials. “All you need is a little catalysis to make carbon nanotubes instead of fullerenes.”

A car’s catalytic converter, which turns toxic carbon monoxide into safer emissions, bears at least a passing resemblance to the Rice-invented high-pressure carbon monoxide, or HiPco, process to make carbon nanotubes, he said. “So it is not a big surprise, when you think about it,” Wilson said.

The team led by Wilson, Fathi Moussa of Paris-Saclay University and lead author Jelena Kolosnjaj-Tabi, a graduate student at Paris-Saclay, analyzed particulate matter found in the alveolar macrophage cells (also known as dust cells) that help stop foreign materials like particles and bacteria from entering the lungs.

The researchers wrote that their results “suggest humans are routinely exposed” to carbon nanotubes. They also suggested previous studies that link the carbon content of airway macrophages and the decline of lung function should be reconsidered in light of the new findings. Moussa confirmed his lab will continue to study the impact of man-made nanotubes on health.

The cells were taken from 69 randomly selected asthma patients aged 2 to 17 who underwent routine fiber-optic bronchoscopies as part of their treatment. For ethical reasons, no cells from healthy patients were analyzed, but because nanotubes were found in all of the samples, the study led the researchers to conclude that carbon nanotubes are likely to be found in everybody.

The study notes but does not make definitive conclusions about the controversial proposition that carbon nanotube fibers may act like asbestos, a proven carcinogen. But the authors reminded that “long carbon nanotubes and large aggregates of short ones can induce a granulomatous (inflammation) reaction.”

The study partially answers the question of what makes up the black material inside alveolar macrophages, the original focus of the study. The researchers found single-walled and multiwalled carbon nanotubes and amorphous carbon among the cells, as well as in samples swabbed from the tailpipes of cars in Paris and dust from various buildings in and around the city.

The news release goes on to detail how the research was conducted,

“The concentrations of nanotubes are so low in these samples that it’s hard to believe they would cause asthma, but you never know,” Wilson said. “What surprised me the most was that carbon nanotubes were the major component of the carbonaceous pollution we found in the samples.”

The nanotube aggregates in the cells ranged in size from 10 to 60 nanometers in diameter and up to several hundred nanometers in length, small enough that optical microscopes would not have been able to identify them in samples from former patients. The new study used more sophisticated tools, including high-resolution transmission electron microscopy, X-ray spectroscopy, Raman spectroscopy and near-infrared fluorescence microscopy to definitively identify them in the cells and in the environmental samples.

“We collected samples from the exhaust pipes of cars in Paris as well as from busy and non-busy intersections there and found the same type of structures as in the human samples,” Wilson said.

“It’s kind of ironic. In our laboratory, working with carbon nanotubes, we wear facemasks to prevent exactly what we’re seeing in these samples, yet everyone walking around out there in the world probably has at least a small concentration of carbon nanotubes in their lungs,” he said.

The researchers also suggested that the large surface areas of nanotubes and their ability to adhere to substances may make them effective carriers for other pollutants.

The study followed one released by Rice and Baylor College of Medicine earlier this month with the similar goal of analyzing the black substance found in the lungs of smokers who died of emphysema. That study found carbon black nanoparticles that were the product of the incomplete combustion of such organic material as tobacco.

Here’s an image of a sample,

 Caption: Carbon nanotubes (the long rods) and nanoparticles (the black clumps) appear in vehicle exhaust taken from the tailpipes of cars in Paris. The image is part of a study by scientists in Paris and at Rice University to analyze carbonaceous material in the lungs of asthma patients. They found that cars are a likely source of nanotubes found in the patients. Credit: Courtesy of Fathi Moussa/Paris-Saclay University

Caption: Carbon nanotubes (the long rods) and nanoparticles (the black clumps) appear in vehicle exhaust taken from the tailpipes of cars in Paris. The image is part of a study by scientists in Paris and at Rice University to analyze carbonaceous material in the lungs of asthma patients. They found that cars are a likely source of nanotubes found in the patients.
Credit: Courtesy of Fathi Moussa/Paris-Saclay University

Here’s a link to and a citation for the paper,

Anthropogenic Carbon Nanotubes Found in the Airways of Parisian Children by Jelena Kolosnjaj-Tabi, Jocelyne Just, Keith B. Hartman, Yacine Laoudi, Sabah Boudjemaa, Damien Alloyeau, Henri Szwarc, Lon J. Wilson, & Fathi Moussa. EBioMedicine doi:10.1016/j.ebiom.2015.10.012 Available online 9 October 2015

This paper is open access.

ETA Oct. 26, 2015: Dexter Johnson, along with Dr. Andrew Maynard, provides an object lesson on how to read science research in an Oct. 23, 2015 posting on his Nanoclast blog (on the IEEE [Institute of Electrical and Electronics Engineers]),

“From past studies, the conditions in combustion engines seem to favor the production of at least some CNTs (especially where there are trace metals in lubricants that can act as catalysts for CNT growth),” explained Andrew Maynard Director, Risk Innovation Lab and Professor, School for the Future of Innovation in Society at Arizona State University, in an e-mail interview. Says Maynard:

What, to my knowledge, is still not known, is the relative concentrations of CNT in ambient air that may be inhaled, the precise nature of these CNT in terms of physical and chemical structure, and the range of sources that may lead to ambient CNT. This is important, as the potential for fibrous particles to cause lung damage depends on characteristics such as their length—and many of the fibers shown in the paper appear too short to raise substantial concerns.”

Nonetheless, Maynard praises the research for establishing that these carbon nanotube-like fibers are part of the urban aerosol and therefore end up in the lungs of anyone who breathes it in. However, he cautions that the findings don’t provide information on the potential health risks associated with these exposures.

It’s a good read not only for the information but the mild snarkiness (assuming you find that kind of thing amusing) that spices up the piece.