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Food Safety Focus (54th Issue, January 2011) – Food Safety Platform

Nanotechnology and Food Safety

Reported by Ms. Shuk-man CHOW, Scientific Officer,
Risk Assessment Section, Centre for Food Safety

Once only existed in the science fiction, "nanotechnology" has become a part of our life. Nanotechnology is being applied in almost every field imaginable. Transparent sunscreens, water repellent pants, anti-graffiti paints, and antimicrobial washing machines are just a few examples of current nanotechnology applications. In this article, we are going to discuss how nanotechnology is being used in the food industry and its potential safety implications.

Nanotechnology and Properties of Nanoparticles

"Nano" comes from the Greek word meaning "dwarf". Nano-sized particles are so tiny that they are well below what can be seen with a typical microscope. To get an impression on the size of a nanoparticle, one can imagine the size of a nanoparticle compared to a football is like the size of a football compared to the Earth (Figure 1). When quantifiable, "nano" refers to one-billionth (10-9己>), therefore, one nanometre is equal to one billionth of a metre.

As a result of the small sizes, the chemical and physical properties of nanoparticles can vary considerably from those of larger particles of the same substance. These differences include colour, conductivity, solubility and chemical reactivity.

Figure 1. The size of a nanoparticle in relation to that of a football is roughly equivalent to that of a football relative to the size of the Earth

Application of Nanotechnology in the Food Sector

Compared to the use in other industrial sectors, the application of nanotechnology in the realm of food is just in the infancy. Nanotechnology is now mainly used for the production of food contact materials in the food industry. For example, nano-silver particles are embedded into plastic containers to inhibit microbial growth and extend the shelf-life of food. Beside the use in food contact materials, nanoparticles can be added directly into food to encapsulate food ingredients and additives, for example to mask the unpleasant tastes and flavours of fish oils. The food itself (e.g. ice cream) may also be made into nano-structure to provide a better texture, taste and consistency.

Safety of Food and Food Contact Materials Derived from Nanotechnology

Whilst most nanotechnology applications for food and beverages are currently at research and development stage, the presence of nanoparticles in food is not a new phenomenon. Many of the commonly consumed food ingredients are comprised of proteins, carbohydrates and fats with sizes extending from large biopolymers down to nanoscale. Nano-sized particles, in fact, are naturally present in our food and we have always been exposed to these very fine particles in the diet.

In view of the rapid development of nanotechnology in the food sector, a number of national and international food safety authorities have recently reviewed the potential food safety implications of the technology. At present, there is no tenable evidence that food or food contact materials derived from nanotechnology are any safer or more dangerous than their conventional counterparts. No general conclusion can be made on the safety of nanofood and food contact materials incorporated with nanomaterials. Up till now, there is no evidence of instances where ingested nanomaterials have harmed human health.

Regulation of Nanofood

While some major countries and regions including the United States, Canada, the European Union, Australia, New Zealand and Mainland China have not yet formulated any specific legislation on the regulation of nanofood, in general it is subject to the same public health and food safety regulations that apply to other food types. According to the World Health Organization, the potential health and environmental risks of nanoscale materials need to be assessed before they are introduced into food. It is stipulated in the Public Health and Municipal Services Ordinance (Cap. 132) that all food intended for sale in Hong Kong shall be fit for human consumption. This principle also applies to nanotechnology-derived food products and the food trade have the responsibility to ensure the safety of engineered nanomaterials in their food products if they are to supply such products. While consumers are likely to benefit from the technology, new data and measurement approaches are needed to ensure safety of products using nanotechnology can be properly assessed.

For more information on safety issues surrounding the application of nanotechnology in the food industry, readers may refer to CFS's literature review on "Nanotechnology and Food Safety".