Nanotechnology: do these tiny particles represent more than a small risk to health?

We have previously examined the potential occupational disease risks of the Fourth Industrial Revolution, where we refer to nanomaterials as the next ‘miracle dust‘ for its asbestos-like qualities, and it is this material that we now delve into and the specific health risks it poses.

Background

Nanomaterials are extremely small particles with extraordinary properties of size, strength, lightness and conductivity with exciting commercial potential. They are employed mostly as composites in thousands of products in industries as diverse as electronics, paints, medicine and tyres. Within the next seven years, it is estimated that two million people worldwide will be involved in their manufacture and many downstream. 

Asbestos was similarly widely employed for its remarkable properties with well-known disastrous consequences for employees, industry and insurance markets.

Within the development of nanotechnology, extraordinary scientific leaps reach the market very quickly. Hailed as the answer to all our problems, little is known about the long-term health implications and research into such implications have not kept pace with the changes.

What is the risk?

What the research does suggest is that certain types of nanomaterials may pose a potential high risk of respiratory disease in the workplace if inhaled, and share physical features in common with asbestos. Just like asbestos, they have a high aspect ratio, in that their length is many times longer than that of their width and their long, thin fibres are chemically inert and biopersistent, so they are not easily broken down in the body.

One example, carbon nanotubes (CNTs), which are tiny hollow carbon tubes, raise serious concerns. Such concerns include that if they are retained in the pleural cavity for long periods, this could cause inflammation and lead to fibrosis and lung cancer. They are also potential carcinogens, which is a substance capable of causing cancer in living tissues and indeed CNTs have been shown to cause mesothelioma in mice. And if the processes in which they are used produce airborne particles or aerosol then the risk to a persons health is increased.

A key worry with such possible health risks is that they are not being correctly identified. Indeed, some manufacturers’ material safety data sheets (MSDS), which is a document containing information on a materials potential hazards and how to work safely with it, do not identify CNT as a potential cancer risk. It is this MSDS that employers base their risk assessments on. If that is flawed, so will the resulting control measures in regard to ventilation, extraction, and respiratory protective equipment. 

Government response

In October 2017, the Parliamentary Office of Science and Technology published a ‘note’ on the risk assessment of nanomaterials. They confirmed that current regulatory frameworks apply to nanomaterials within the UK, mainly set at the EU level. They also acknowledged that there are some indications of potential health and environmental risks but that conclusions are limited by insufficient long-term evidence and difficulties in translating results from the laboratory to the real world. They have also confirmed that post-Brexit, the UK will need to establish a regulatory framework for nanomaterials.

Regulation of nanomaterials

The occupational use of nanomaterials is regulated under the Control of Substances Hazardous to Health 2002 (COSSH). COSSH requires employers to control substances that are hazardous to health, which they have confirmed includes nanomaterials. We do not believe that COSSH is necessarily inadequate, but rather that strict adherence is required following a precautionary risk assessment process.

For nanomaterials this would be:

Work Place Exposure Limit (WEL)

There are no current WELs for nanomaterials.

What the health hazards are?

Limited research but for certain kinds of nanomaterials, such as CNTs, there is concern that the risks are similar to asbestos, so this would be cancer and also potential skin and eye problems.

How to assess the risk

Precautionary approach mandated. This will be informed by whether the material is bound in a matrix, suspended in solution, or dry and free, giving rise to risk of, for example, inhalation.

Providing control measures to reduce harm to health

Minimise potential to make material airborne. Ventilation, extraction, very high grade respiratory protection (RPE) type D would be required.

Health surveillance

Health and Safety Executive advice is that ‘Health monitoring is appropriate where health effects are strongly suspected but cannot be established. For nanomaterials if a risk assessment for handling the non-nanomaterials form requires health surveillance, then health monitoring of work using the nanoform might be appropriate’.

As a new technology, the long-term risks of exposure associated with nanomaterials are not currently fully understood, despite being widely used. Whilst knowledge gaps exist, the Health and Safety Executive (HSE) recommend precaution when dealing with scientific uncertainties, as part of the ‘Precautionary Principle of the United Kingdom Interdepartmental Liaison Group on Risk Assessment’.

The EU Registration, Evaluation, Authorisation and Restriction of Chemicals Regulations (REACH) aims to improve the protection of human health from risks posed by chemicals. REACH applies to the manufacture and import of chemicals and as such, set out onerous and detailed health and safety information on chemical hazards relevant to its requirements.

Further, down the supply chain, employers may consider consulting the detailed REACH hazard risks to prepare a better, more detailed risk assessment rather than rely on a potentially flawed manufacturer’s MSDS.

Comment

Clearly urgent research is needed into the long-term health implications as widespread use of nanomaterials continues. Given the amount of products in diverse industries, insurers and underwriters should consider auditing their insureds to see whether nanomaterials are involved. If so, whether they want to insure that risk and if they do, whether appropriate risk assessment and control measures are in place.

We have clear historical precedents for catastrophic mistakes of this nature with the legacy of asbestos, which was the groundbreaking material of its time. Let us learn from the past to avoid repeating the mistakes in the future.

For now, it makes sense for employers to assume the worst health implications for new materials and to protect their employees.

Read other items in Occupational Disease Brief - September 2019

Related item: Fourth industrial revolution - asbestos round two?