Nanomaterials and health: regulation playing catch-up with reality
David Thorpe | 28 January 2016
Nanomaterials are increasingly being used in the industrial, built and consumer environments but concern is mounting over their potential negative environmental and health effects.
As yet there is no international regulation of nanoproducts or the underlying nanotechnology, nor are there any internationally agreed definitions or terminology for nanotechnology.
There are also no internationally agreed protocols for toxicity testing of nanoparticles, and no standardised protocols for evaluating the environmental impacts of nanoparticles.
In such conditions, what chance do legislators have of protecting us and the wider environment?
What are nanomaterials?
Nanomaterials are invisible to the naked eye: up to 10,000 times smaller than the diameter of a human hair. They have applications right across science and industry, from colloidal gold in targeted drug delivery through to carbon nanotubes for renewable energy capture. They are also used in the consumer market in clothes, personal care products and cosmetics, as well as in the construction, medical, automobile, environmental and safety technology sectors.
Consequently, they are likely to become ubiquitous and unavoidable in future, with increasing risk of unintended releases from the product life cycle.
If they enter the waste stream, they could well end up in soil, watercourses and air. What happens, for example, when these substances are incinerated? What are the acute and chronic toxicity effects? Could they impair DNA, cross and damage tissue barriers, find their way into people’s brains, gastrointestinal systems or respiratory tracts?
Around the world, investigation is only just beginning to get to grips with these immensely complex issues, amongst which is the question of the effectiveness of existing environmental legislation in regulating the field.
Many substances comprising nanometre-scale particles have already been in use for decades such as carbon black, titanium dioxide, zinc oxide, bentonite, aluminum silicate, iron oxides, silicon dioxide, diatomaceous earth, kaolin, talc, magnesium oxide and copper sulphate.
But particle sizes have shrunk of late and more exotic substances such as carbon nanotubes and colloidal silver are coming into mass production.
The level of ignorance
In November last year, a study looking at fine particulate matter in the lungs of asthmatic children found that most of the fine particulate matter (known to adversely affect lung function) investigators discovered consisted of man-made carbon nanotubes.
The danger of this channel of entry into the human body was confirmed at the end of last year when the Danish government published the result of a four-year study into the health effects of nanomaterials, and found that their inhalation presented a greater risk than contact with the skin from powder or liquid products. An example given is via “spray painting using a spray gun without proper protective equipment, an activity that would be hazardous even if no nanomaterials were present in the paint”.
The report, Better control of nanomaterials, combines the results of 30 Danish reports in the study, another product of which was the establishment of a Danish nanoproduct register.
However, the Danish EPA says there is a need for more information on where and which nanomaterials are used, and the extent to which consumers and the environment are exposed to them, and so the “conclusions of this summary report should therefore be taken with some reservation”.
Aquatic organisms breathe through water and so we would expect that, as with plastic in the ocean, nanoparticles that enter watercourses would endanger these organisms – and hence, as it would be in the food chain, us. This is verified by a recent study by the University of California Centre for Environmental Implications of Nanotechnology into the way silver nanoparticles are absorbed by fish.
Silver nanoparticles are found in a wide array of consumer items, from cosmetics to socks, and the researchers predict that over 60 tonnes a year may reach surface waters in the United States alone.
Although many studies have compared particulate and ionic toxicity, few have looked at size effects, say the researchers, who found “striking and consistent” size-dependent structural differences in gills and intestines, caused by particles as tiny as 20nm. They speculate that gill cells could mistake silver ions for sodium ions, disrupting ion channel function and inhibiting the enzyme ATPase. The health effects of this are still unknown.
The outer limits of regulation
Many states around the world try to accommodate these unknown risks in conventional chemicals use legislation, but are struggling to adapt to this fast-moving field.
The European Commission concluded in 2012 that its regulations governing chemical releases into the environment – through industrial effluent or household waste water – such as REACH, the EU’s chemicals regulation – can apply to nanomaterials but that they contain gaps and challenges. Most important of these is that there is currently no guidance on the EU recommendation for a definition of nanomaterials.
The definition is being reviewed by the commission but its decision on whether, or how, the definition should be changed is expected around the same time that the European Chemicals Agency’s guidance moratorium takes effect in mid-2016. This is before the European Commission issues its proposal for changing REACH’s information provision annexes to take account of nanoforms.
The EC has commissioned a consultancy, Ricardo Energy & Environment, to help it identify and overcome these regulatory gaps, enlisting legal specialists and nanomaterials scientists, teaming them with experts in chemical risk and regulatory policy from the UK’s National Chemical Emergency Centre, a subsidiary of Ricardo Energy & Environment, plus expert partners from the Technical University of Denmark and Milieu Consulting.
Ben Grebot, who is Ricardo Energy & Environment project director, observes that “developing appropriate regulations for these materials is an important step to supporting this burgeoning industry and fast moving area”.
“Effective legislation provides high levels of environmental protection, promotes sustainable growth and supports new industries to develop their green potential by providing cleaner solutions to societal challenges.”
North American regulation
In North America the US Environmental Protection Agency is also developing a scientific foundation to better understand, predict and manage the challenges of nanomaterials. There, the Administration has chosen to use the Toxic Substances Control Act to control nanoscale materials. It works with Canadian authorities to coordinate their approach.
Before they can even manufacture these chemicals, firms have to notify the EPA, which has reviewed over 170 of these applications since 2005. It then decides whether to permit limited manufacture of the materials through the use of consent orders or Significant New Use Rules under the TSCA. It can also grant certain regulatory exemptions, but only where it believes exposures are tightly controlled to protect against unreasonable risk.
On a more global scale, the Organisation for Economic Cooperation and Development has established a working party on manufactured nanomaterials, which is engaged in a variety of projects to further understanding of the properties and potential risks of nanomaterials.
It has just published the results of a three-year survey of existing legislation, research and development in the field. While it identifies most of the work proceeding in the European Union, some is also occurring in Australia, focused on the human health hazards of carbon nanotubes and other engineered nanomaterials, conducted by Safe Work Australia.
Safe Work Australia has identified that duties under existing workplace legislation apply to working with engineered nanomaterials as they do to technologies, substances, chemicals and materials generally, requiring risks to be eliminated or minimised and communicated. The onus is on the workplace managers to comply with the regulations.
But do employers have understanding of the applications? Safe Work Australia publishes an information sheet on the approach to be taken for nanomaterials emissions and exposure management in the workplace. But what happens outside the workplace is not its concern.
This is partly the responsibility of the Department of Health National Industrial Chemicals Notification and Assessment Scheme, which regulates industrial nanomaterials used in products such as paints, dyes, inks and surface coatings, plastics, cosmetics and consumer goods. Other government agencies are responsible for regulation of nanomaterials in medicines, food, pesticides and veterinary medicines.
Wherever you look there are gaps between industrial practice, research, current knowledge and legislation. Back in Brussels, the European Chemicals Agency has called for “transparency measures”, such as a nanomaterials “observatory” – a website presenting existing information on nanomaterials on the EU market.
Many would suggest that such an observatory should be global in scope.