ChemRegs Newsletter – November 2017
Are carbon nanotubes the new asbestos?
There is new medical data to suggest that carbon nanotubes and asbestos may be revealing similar hazardous attributes.
A study by the Medical Research Council (MRC) has found that some manufactured carbon nanotubes are similar to asbestos in terms of their fibrous shape and bio-persistent properties and thus may pose an asbestos-like inhalation hazard.
Mesothelioma, a fatal tumour of the pleura, is strongly associated with asbestos exposure. The research done by the MRC’s Toxicology Unit showed that placing carbon nanotubes or long asbestos fibres into the pleural cavity of mice induces mesothelioma exhibiting common pro-oncogenic molecular events throughout the latency period of the disease progression. In other words, carbon nanotubes act like asbestos on the lungs in causing mesothelioma.
The researchers also found that, like asbestos fibres, long nanotubes caused long-term inflammation in the pleural space. Over time, this inflammation led to inactivation and loss of the specific genes that suppress the formation of tumours which, in people with mesothelioma, are also found to be altered.
Dr Nathan Richardson, Head of Molecular and Cellular Medicine at the MRC, said “Asbestos-related mesothelioma diagnoses have risen significantly since the 1990s, but are projected to fall steadily in the UK over the next couple of decades – thanks to greater awareness of the dangers, banning much of its use and improved health and safety measures where people can become exposed.”
One of the reasons for the continued terrible death toll of asbestos is the ugly fact that it was so damn useful.
The magical usefulness and, lets not be coy, commercially profitable attributes of asbestos were incorporated into a vast range of everyday products such as household decorating paint and products, cars, aircraft, insulation boards, toys etc. I remember my family even had an asbestos ironing board from the 1950s! Its industrial uses were legion – roofing, ducting, thermal insulation and so on.
From homes to factories, cars to aircraft, farming to fishing – these have all found a use for asbestos. It is cheap and it is plentiful.
However, as early as 1897, doctors attributed pulmonary troubles in patients to the inhalation of asbestos dust. Factory inspectors in 1898 reported “widespread damage and injury of the lungs, due to the dusty surrounding of the asbestos mill.”
Asbestos is of great antiquity and over 6000 years ago it’s long hair-like fibres were used for wicks in candles.
Between 4000-5000 years ago, embalmed bodies of Egyptian pharaohs were wrapped in asbestos cloth to protect the bodies from deterioration. Undiscovered mummies will still be preserved and wrapped in asbestos. The curse of the pharaohs maybe?
The Romans were said to have woven asbestos fibers into a cloth-like material that was then sewn into tablecloths for feasts. The cloths were cleaned by throwing them into a fire, from which they came out magically intact and amazingly whiter than when they went in. However, Pliny the Elder wrote of the disease of the slaves that mined and made the cloths, remarking they died unusually young.
We can see that asbestos was cheap, very useful, and life changing.
Nano materials are displaying the same game-changing usefulness that asbestos once did.
Carbon nanotubes are a form of carbon that have a long, hollow structure with a diameter of only a few nanometres (around one-billionth of a metre, or about 10,000 times smaller than a human hair) but up to several centimetres long.
Carbon nanotubes can lead to significant improvements in the mechanical properties of biodegradable polymeric nano composites for use in tissue engineering, including bone formation. They can be incorporated into paints and coatings to prevent antifouling of ships hulls, preventing the need for hazardous biocidal paint. Solar panel development into ever smaller and thinner surfaces will use nano technology. It is envisaged that new buildings and structures will be ‘smart’ within a few years, to power a new smart grid.
Carbon nanotubes can produce materials with toughness unmatched in the man-made and natural world. This means that the built environment and infrastructure can be radically rethought.
It seems we made some fundamental mistakes many years ago with asbestos. We did not want to recognize the deleterious health effects of this magic material because we thought the benefits outweighed the disadvantages.
We need to ensure that we ask some fundamental questions of nano technology early on in its development.
How do we produce it safely?
More importantly, how is it to be destroyed when we are finished with it?
How do we reuse or repurpose the waste of the destroyed product?
With asbestos the answer to the above is easy. As asbestos is a naturally occurring mined product, you simply dig a big hole and bury it.
Nano technology is man made and very strong and stubborn.
Professor Anne Willis, director of the MRC Toxicology Unit and the study’s co-author, said
“We want our research to inform manufacturers and regulators about safer options and contribute to a ‘Safe by Design’ approach when a nanofibre is being selected for the production of nanomaterials for emerging technologies.”
A lot of thought will be needed to ensure that nanotechnology does not become the new asbestos.
Consultation on new and revised Workplace Exposure Limits (WELs)
HSE is consulting on the implementation of new and revised Indicative Occupational Exposure Limit Values (IOELVs) in Great Britain.
This consultation relates to the implementation of Directive 2017/164/EU introducing the 4th list of Indicative Occupational Exposure Limit Values (IOELVs) for thirty-one chemical substances to help protect workers from the ill-health effects of exposure to hazardous substances in the workplace.
The 4th IOELV Directive was adopted by the European Commission on 31st January 2017.
The Consultative Document sets out the HSE’s proposals for establishing Workplace Exposure Limits for the substances listed in the Directive, in order to implement it in Great Britain. Note – until exit negotiations are concluded, the UK remains a full member of the EU and all the rights and obligations of EU membership remain in force.
Substances under consultation include acetic acid, ethyl acetate, bisphenol A, and dichloromethane.
There are currently IOELVs for 115 substances listed in three directives, which have been adopted since 2000 (2000/39/EC, 2006/15/EC and 2009/161). In the UK these limit values are transposed as Workplace Exposure Limits (WELs) via an amendment to the HSE publication EH40/2005.
A WEL is defined as the concentration of a hazardous substance in the air that people breathe, averaged over a specified reference period referred to as a time-weighted average (TWA). Two periods are used: long-term exposure limit (8 hours) and short-term exposure limit (STEL) (15 minutes).
IOELVs are health-based occupational exposure limit values derived by the Scientific Committee on Occupational Exposure Limits for Chemical Agents (SCOEL) from the most recent scientific data available. They are adopted by the European Commission taking into account the availability of measurement techniques.
EU Member States are obliged to establish national occupational exposure limits for the chemical agents in question, taking into account the European values. In most cases this will mean that the British limit will be identical or very close to the IOELV. Only in very rare circumstances would HSE consider establishing a WEL at a level substantially higher than the IOELV.
The consultation commenced on 10 November 2017 and will end on 2 February 2018.
To take part, go to http://www.hse.gov.uk/consult/condocs/cd283.htm
Brexit and REACH
A few more snippets of information regarding REACH are being made public by the government.
Comments from a conference last week held by the Chemicals Industries Association (CIA) show that the money already invested by business in complying with REACH is a live issue in the Brexit talks.
Here are a few of comments from the speech notes made by Steve Baker, a junior minister in the Department for Exiting the European Union:
“We understand the concerns of businesses regarding the validity of their REACH registrations, as well as the costs that industry have already invested to comply with REACH”
“The UK’s position is clear. We want existing registrations, authorisations and approvals to remain valid in both the EU and UK markets. Clearly, this is in the interests of businesses in the UK and the EU. It recognises the complex compliance activity that takes place through supply chains.”
“We understand the concerns of businesses regarding the validity of their REACH registrations, as well as the costs that industry have already invested to comply with REACH. We have been listening to what businesses and others have been telling us about their concerns for the future and the potential impacts and opportunities of EU Exit. We will continue do this.”
At times getting any inclination on what is being negotiated in the Brexit talks is as rare as hen’s teeth.
However, these speech notes contain a useful insight that the investment made by businesses in complying with REACH is not taken for granted, reinforced by the following comment:
“I can assure you that this matter has been a key topic of the opening phase of negotiations”
The speech notes can be read here in full: CIA speaking note
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