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Nanoparticles and nanosafety: the big picture

Nanoparticles — or nanomaterials, as they are often called — are chemical objects with dimensions in the range of 1-100 nanometres (nm). Particles this tiny are hard to imagine, but it may help to think…

Nanosafety research ensures everyday use of nanoparticles – such as sunscreen – stays safe. Flickr/Eliya

Nanoparticles — or nanomaterials, as they are often called — are chemical objects with dimensions in the range of 1-100 nanometres (nm).

Particles this tiny are hard to imagine, but it may help to think that a 1nm nanoparticle could fit up to 80,000 times across a human hair.

Nanoparticles occur naturally in the environment, such as in clay, milk, and in volcanic ash and sea spray.

Manufacturers also make nanoparticles for use in a range of everyday products.

  • The surfaces of your fridge may hold silver nanoparticles to stop bacteria growing
  • Sunscreen applied as a clear film to your skin may contain zinc oxide or titanium dioxide nanoparticles to provide broad-spectrum sun protection
  • The frame of your new bicycle may even contain carbon nanotubes to make it stronger and lighter than older bikes.

Nanoparticles are intriguing to scientists because the properties of a chemical — such as silver or zinc oxide — in nano form can be very different to a larger particle of the same chemical.

This is because surface properties dominate in the nano form (due to higher surface area). It’s the internal composition that defines the properties of larger particles. This difference opens up a range of new uses for that chemical.

What are the benefits of nanomaterials?

Nanotechnology research. Flickr/Brookhaven National Laboratory, CC BY

The prevalence of manufactured nanoparticles is increasing.

New developments have led to significant advances across a broad range of electronic, medical and environmental applications (among others).

Nanoparticles may be more conductive, stronger or more chemically reactive than larger particles of the same substance.

This means smaller amounts of the chemical in nano form can achieve the same effects, making a product cheaper – or the same quantities may be used to create an enhanced product.

What are the potential risks?

The same properties that make nanoparticles promising for new manufacturing opportunities may also present new risks to us and our natural environment.

Normally, new chemicals and their commercial use would be assessed by one or more of a number of regulatory bodies within Australia. But if a chemical in traditional form has already been assessed, it may not require further scrutiny by regulators if it is made in nano form. That’s the case even though the two forms of the same chemical may have quite different properties.

It is this “slipping through the cracks” that has raised some concerns in the community about the large-scale use of untested nanomaterials.

Assessing the risks associated with manufactured nanomaterials is never easy or straightforward. Unlike traditional chemicals, the classification of the properties and potential risks of nanomaterials is not based on composition alone.

Rather, it is a complex function of a number of properties, including particle size, shape, surface area, surface coating and even how tightly the particles are clumped together.

Adding to the challenge, many of these properties can change with time and through use as the nanomaterials move through a complex system, such as our own bodies or a waste-treatment plant.

What safety research is being done?

In 2007 the Working Party for Manufactured Nanomaterials, in the Organisation for Economic Cooperation and Development (OECD), launched an international programme to test 13 different types of manufactured nanomaterials that were in the early stages of commercialisation.

CSIRO

OECD member countries were invited to comprehensively test these nanomaterials for their physical and chemical properties, their fate and transport in the environment, and their potential toxicities in a range of biological systems.

Australia took part and tested a number of zinc oxide, cerium dioxide and silver nanoparticles. The CSIRO was a major contributor to the Australian effort.

This international effort gave clarity on the types of nanomaterial properties needed for toxicity assessments, and developments on how to make those measurements. While these are important steps forward, more work still needs to be done before such measurements will be routine.

The timeline to achieve this is tight, especially for Australian companies that export internationally. New regulations will be in force this year in Europe that require mandatory labelling of certain nano-containing products.

This is by no means a simple task. It is not easy to find — let alone count and measure sizes of — these very tiny particles in complex products. This makes it tricky to determine whether they are even captured by the definition of “nano” and hence require labelling.

At present, CSIRO’s nanosafety team is investigating

  • nanoparticles in sunscreens
  • the environmental effects of nanoparticles added to fuels for combustion engines
  • whether nanoparticles eaten by freshwater animals are excreted or retained and then transported up the food chain
  • whether nanoparticles are produced in bush fires.

Ongoing research in this area is both relevant and vital to the future of Australian manufacturing.

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7 Comments sorted by

  1. garybass

    Education IT Physics

    In particular, what is the course of action with sunscreen? The 'time bomb' aspect applies to children..perhaps if in doubt don't!

    Unlike use of asbestos in 40s, 50s and 60s which allowed unfettered use anywhere...most notably in every science classroom over a Bunsen burner...every science student of those times has been exposed to both blue and white asbestos.

    New material technologies first need to be identified then regulated before exposure...zinc nano particles have been identified as an increased risk...now for the regulation.

    Free market or self regulation has proved itself to be completely unreliable with reg to consumer damages..witness self regulating building industry in Qld and NSW..and effectively Victoria.

    Lets have self regulating traffic speeds...would save more in wages, material than speed cameras raise!..Darwin solution to poor driving as well!?
    ..maybe not..

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  2. Michael Shand

    Software Tester

    Gob bless the CSIRO and the job they do, I wouldn't want to count Nano particles

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  3. Terry J Wall

    Still Learning at University of Life

    The real thought provoking and puke generating consideration is:
    Just how weak is our regulatory mechanism that allows these irrecoverable uncountable thingies to be made and included in everyday products without any medium to long term testing. Humans are clearly just things to farm.

    I can remember the day when the FDA used to work for the well being of people; it was an independent group of scientists and administrators set up and charged for this very purpose.
    Today if there is a buck in it, it hits the market first and fast, then it takes our tax payer funded CSIRO et al to finally say "Shit I suppose we ought to test these things". Too bad if they have bad press eh! Your try stuffing genies, whom you cannot even count, back into their vases.
    Ya gotta love them multinationals and their lobbyists, not to mention the deafening silence from doctors.

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  4. Bruce Tabor

    blogger

    One pervasive source in our modern urban environment is the emission of ultrafine particles (<100 nm) in diesel emissions. "Ultrafine particles" (UFP) was the old name before nanoparticles became sexy.
    http://en.wikipedia.org/wiki/Ultrafine_particles

    As we buy more and more diesel cars and have more trucks on the road we are exposed to greater amounts of UFPs, which are " more carcinogenic than cigarette smoke":
    http://www.abc.net.au/health/features/stories/2003/07/03/1835282.htm

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  5. Mia Masters

    person

    "The Report found a number of areas of consensus or emerging consensus, which included for example: that the social and economic implications of NT are intimately linked to questions of risk communication and risk perception amongst publics; that public perceptions of NT and public engagement are potentially crucial issues in NT; that a more rigorous and open debate about NT and the social and economic impacts therefore is warranted. There is an emerging consensus that NT have disruptive potential and are likely to result in unintended consequences. There is less consensus about the degree to which these will be negative, or positive or both."
    The Social and Economic Impacts of Nanotechnologies:
    A Literature Review
    Final Report February 2009
    Prepared for the Department of Innovation, Industry, Science and Research
    Submitted by:
    Ms Kate Seear, Professor Alan Petersen and Dr Diana Bowman
    Monash University Victoria, Australia

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    1. Mia Masters

      person

      In reply to Mia Masters

      "Despite emerging consensus in some areas, there continues to be a range of widely divergent perspectives on the potential social and economic impacts of NT. Areas where consensus is lacking include: the nature and extent of potential disruption arising from NT; the timelines for disruption; whether the disruptive potential of NT is necessarily positive, negative, or both; the precise form of regulatory action that is required, by whom, and in which areas; the appropriate approaches to public engagement; and whether NT pose unique or entirely new ethical, social and economic questions for societies, or whether they merely intensify or exacerbate existing concerns and inequalities."
      (same report)

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  6. Mia Masters

    person

    "These results provide the first conclusive evidence that Zn from ZnO particles in sunscreen penetrates healthy skin and is observed in blood and urine. Whether the Zn is present as particles or soluble Zn ions is unknown at this stage
    These studies have been approved by human ethics committees at Macquarie University and CSIRO."
    Dermal absorption of ZnO particles from sunscreens applied to humans at the beach
    Brian Gulson1, 2, Maxine McCall3, Laura Gomez1, Michael Korsch2 , Phil Casey4, Les Kinsley5
    1Graduate School of the Environment, Macquarie University, Sydney NSW 2109, Australia 2CSIRO Exploration and Mining, North Ryde NSW 2113, Australia
    3CSIRO Future Manufacturing Flagship, North Ryde NSW 2113, Australia
    4CSIRO Future Manufacturing Flagship - Clayton VIC 3168, Australia
    5Research School of Earth Sciences, Australian National University, Canberra ACT 2601, Australia

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