The increasing number of applications for nanotechnology have resulted in the generation of waste containing synthetic nanomaterials. It is important that the disposal of this waste does not cause environmental and health impacts from hazardous substances. The use of synthetic nanomaterials in plastics or metals should not have a negative affect on recycling.
Synthetic nanomaterials can be found today in cosmetics (UV protection), paints (anti-corrosion), textiles and synthetics (water repellent, anti-bacterial). Nanotechnology and nanomaterials will also be used in other areas in future, for example medicine, vehicle construction, energy and environmental technology.
Synthetic nanomaterials consist of particles with one or more external dimensions of fewer than 100 nanometres. The most common materials include carbon compounds (e.g. carbon nanotubes, CNT), oxides, e.g. silicon oxide and titanium oxide, metals, e.g. silver and gold, semi-conductor elements, organic polymers, and so-called "bio-inspired nanomaterials", e.g. micelles, liposomes and proteins.
Due to their minute dimensions and special structures, nanomaterials can have different chemical and physical properties to the non-nano version of the same substance. For example, the electric conductivity and chemical reactivity of a substance can change during the transition to the nano range. As a result new options for the application of such substances arise. At the same time, however, this can result in increased toxicity or the greater bioavailability of the substances.
The chemical-physical properties of many nanomaterials and the properties that pose a risk to health and the environment are not entirely known; neither is their behaviour in the environment. The risk potential also depends on their water solubility and agglomeration state. It may not be assumed, therefore, that all nanomaterials have hazardous properties.
During waste disposal, particular care should be taken to ensure that no nanomaterials are released that could pose a threat to human life and the environment. Recycling must not be impaired either. If plastics or metals with nanomaterials could reduce the quality of a process or product, they must not be allowed to enter existing recycling processes.
The handling of free or releasable nanomaterials in pure or concentrated form involves greater risk potential than that of other forms of waste. Waste from such materials may be expected to arise during production and during industrial or commercial use. The FOEN has developed a Policy Paper on the Safe and Environmentally Sound Disposal of such waste. It describes the measures necessary for dealing with nanowaste and the principles for its disposal based on the current status of knowledge and taking the applicable legislation into account. The disposal process should ensure that the waste is stripped of its hazardous and nano-specific properties. Depending on the nature of the waste, thermal or chemical-physical processing of the waste are possible solutions.
According to the chemicals legislation, manufacturers must implement self-regulation measures prior to placing their products on the market. The manufacturers of nanomaterials must also check whether their substances, preparations or objects could pose a risk to health or the environment when disposed of. Products may only be placed on the market if there is no risk, or the risk is minimised through protective measures. Verification processes suitable for nanomaterials are currently being developed.
In the case of nanowaste in concentrated form from production and industrial use, waste disposal companies must prove that the proposed waste disposal process is environmentally sound. To provide this proof, the company may carry out tests itself or refer to existing scientific tests. New processes must be developed in some cases. If the proof provided by the company is accepted by the cantonal office, it will be granted a permit for the acceptance and processing of this waste.
In the case of waste from consumer goods and other mass waste containing nanomaterials, the FOEN evaluates the disposal processes that must be used and to what extent, and identifies the risks that exist in relation to work safety, health and the environment. Further research needs to be carried out in this area.
The FOEN aims to close these gaps in the knowledge by supporting research and through participation in international bodies (e.g. the OECD).