Employers are required to ensure safe workplaces, including informing workers and their representatives of the use of substances that could affect worker health and safety. Employers must make available to workers the Safety Data Sheets on substances such as nanomaterials, and they are also required to undertake a risk assessment on use of hazardous substances at the workplace.

Unfortunately, the Safety Data Sheet does not always contain useful enough information to help prevent worker exposure or to help in the risk assessment, so it is important to know which nanomaterials are used so that the employer can gather as much information as possible on the substance. Many aspects of the nanomaterial could be important in identifying its hazard profile, including the number of dimensions – we still do not know which are most important for each nanomaterial. This is why it is important to gather as much information as possible on each nanomaterial used: shape, size, chemical composition, etc. This information helps the employer and workers to build up a profile of the material used. This is also relevant to how much is used, particularly as this information is useful in the development of exposure scenarios needed for the risk evaluation. The downloadable table provides more details on four classifications of nanomaterials.

Employers are legally required to determine and assess risks of hazardous substances at the workplace, and to inform workers of their introduction into a workplace (ideally, before the substance is introduced). As hazard data on nanomaterials is still incomplete, a precautionary approach is needed, using the highest level of worker protection. Exposure information is needed, and the employer can do this with existing nanoparticle counter and characterisation technologies. These should be used for each activity in the workplace where nanomaterials could be released – material reception, production, use, and maintenance and cleaning. Given that little information is available in Safety Data Sheets, employers will likely need to seek more information from the nanomaterial or product manufacturer. For their risk assessment they should ask whether the product has been tested for the following hazardous properties:

1. Acute toxicity (Acute Tox. 3)
2. Irritation (Skin Irrit. 2)
3. Skin sensitisation (Skin Sens. 1)
4. Mutagenicity (Muta. 2)

The potential for worker exposure to manufactured nanomaterials is highest when working with the powder form, or if dust is created when working with an object containing manufactured nanomaterials (such as machining, sanding, grinding, drilling, polishing, sawing, etc.). Workers can also be exposed to nano-sized particles when machining products not containing manufactured nanomaterials. Care should also be taken for workers providing maintenance and cleaning operations as worker exposure can occur here as well.

It is especially important to avoid creating or inhaling dust, where nanomaterials can be found. It is important for any particle captured in the lungs to be cleared quickly and not to remain there. Biopersistency is the ability of a particle to remain in the lung or the human body. A biopersistent particle in the lung for example can lead to adverse health effects caused by enhanced inflammation, tissue damage, effects on genes, etc. This is particularly relevant for rigid and biopersistent fibrous materials that can be breathed in and have an effect like asbestos. Certain types of nanomaterials have a similar shape to asbestos and for these, a hazard assessment must be compared to the one of asbestos.

Employers should ensure that worker exposure to hazardous substances is minimised as much as possible, of preference by substituting hazardous (or potentially hazardous, in the case of nanomaterials) with less or non-hazardous substances. If hazardous substances cannot be substituted, risk management measures to ensure high worker health and safety protection must be put in place. In addition to organisational measures (policies, procedures, etc.), work organisation and technological measures should also be assessed and introduced as needed: separation of work activities to isolate hazardous substance release, installing enclosed systems or local exhaust ventilation or testing these for the specific nanomaterial if these are already in place. Personal protective equipment is the last option for consideration of risk management measures, and the equipment used should correspond to the risk level associated to the nanomaterial in the risk assessment delivered by the employer. If there is still uncertainty as to the risk level, the highest level of protection should be used.

As for other hazardous substances, a worker exposure registry for each worker potentially exposed to nanomaterials should be expanded to include the nanomaterials, and assessed in the case of worker health problems. A worker exposure registry helps to identify workers exposed to nanomaterials (or other substances wishing to be “tracked”), and to maintain communication with these workers in a structured and organised way. This tool is useful for surveillance of new or potential hazards, including nanomaterials. The downloadable form can be used as a starting point for gathering detailed information on potential exposure situations and levels for each employee. However, they are not a final solution on their own as it will not always be possible to identify a direct causal link between exposure to a specific substance and an immediate physical effect, or even one that takes a longer time to appear. Nonetheless, a worker exposure registry can be a useful element of an “early warning system” that can identify trends in a more comprehensive way than anecdotal evidence.