It's like you shrink a cat and keep shrinking it, and then at some point, all at once, it turns into a dog. (1)
"How about a glass of wine?--Any particular flavor?--Would you like to add nutrients to it?--What color of wine do you want?" This is not a dialog from a sci-fi book, but a likely reality of a notso-distant future. Scientists at Kraft Foods have developed a "colorless, tasteless liquid" that allows consumers to design their own drink after purchasing it, depending on their desires at the moment. (2) The liquid includes nanocapsules two thousand times thinner than a strand of human hair that contain the necessary chemicals to produce any drink the customer wants. (3) A specific microwave wavelength will activate the nanocapsules containing the chemicals needed to produce the requested drink, while those remaining inactive will pass through the body unnoticed. (4) An "electronic tongue" comprising an array of nanosensors and serving as an indicator of chemical changes could help to release "controlled amounts of the suitable molecules to tailor the smell, taste and goodness of the product for the individual consumer." (5)
Nanotechnology Development and Definitions
Nanotechnology is currently understood as a branch of science dealing with materials at the length scale from one to one hundred nanometers. (6) One nanometer equals one billionth of a meter; a strand of human hair roughly equals 100,000 nanometers wide. (7) Nanotechnology traces its origins to a lecture titled "There's Plenty of Room at the Bottom," presented by the Nobel prize-winning physicist Richard P. Feynman at the annual meeting of the American Physical Society in December 1959. (8) In this lecture, Feynman introduced the idea that materials can be manipulated on a small scale for storing large amounts of information, which creates small computing devices; ultimately, these devices could allow the synthesizing of any chemical substance or the building of any device by arranging atoms "one by one" at the atomic level. (9)
These ideas started to migrate from science fiction to reality almost thirty years later. Indeed, the real development of nanotechnology started less than ten years ago, and the field has been growing exponentially since that time. In 2006, sales of products using nanotechnology reached almost $1 billion, jumping from $150 million in 2002. (10) Some projections (made before the current economic downturn) suggest that the market for nanotechnology-enabled products will reach $1 trillion by 2015. (11) Global research and development spending on the field was $9.6 billion in 2005, up ten percent from 2004. (12)
With all of this activity, one would think that people should at least know how to define the field in which they are working. However, no universally accepted definition of nanotechnology exists. The National Nanotechnology Initiative (NNI) (13) provides a working definition of nanotechnology. (14) Twenty-five federal agencies currently participating in the NNI, including the EPA, the FDA, and the USDA, (15) took part in developing this definition.
The 21st Century Nanotechnology Research and Development Act (16) adopted in 2003 includes a different definition. (17) It is interesting to note that in the last definition, the exact size range for nanomaterials is not established, thus possibly allowing particles over 100 nanometers to qualify as nanomaterials. (18) The ASTM adopted the first formal industry standard for nanotechnology definitions in 2006, (19) which provides a baseline for industry professionals and does limit the size of nanoparticles. (20) However, the ASTM expressly reserves the right "to continually reassess the terms and definitions contained in this standard" as necessary. (21)
Some regulatory agencies have their own definitions; (22) other agencies expressly refuse to adopt a formal definition. (23) Despite the absence of a uniformly accepted definition, the market is growing at an astonishing rate. (24) The governmental and private spending on research and development of new nanomaterials and applications indicates continued expansion in the near future. (25) These new developments are affecting many industries, including food manufacturing, processing, and packaging.
This note will discuss nanotechnology applications relating to the food industry. Many publications and reports prior to this note have wrestled with the adequacy of the current regulatory framework, primarily the Food and Drug Administration (FDA), to regulate nanotechnology. This note will support the FDA's contention that its regulatory framework is adequate to regulate new nanoparticles in food products and food contact (processing and packaging) nanomaterials. (26) However, as to the materials currently used in various food applications, the agency needs to establish specific nano-regulations, explicitly requiring manufacturers to undergo new safety evaluation processes if they change the size and structure of a previously approved substance.
This note will first define the scope of food nanotechnology by describing current and prospective applications of nanomaterials and nanoparticles in food processing, manufacturing, and packaging, including their benefits and risks. Nanomaterials that can be used in food applications will be divided into four classes: nanoparticles naturally existing in food products, (27) nanostructured food products developed twenty to forty years ago, (28) new engineered nanomaterials that do not have analogs on the conventional macroscale, (29) and existing materials currently used in food processing in macroform (conventional size) that potentially can be used in nanoform. (30) Part III of this note will provide an overview of the existing regulatory frameworks of the major federal agencies charged with regulating various emerging nanotechnology applications in foods and food-related industries.
In Part IV, the concepts of risk analysis will be employed to evaluate each of the four classes of food-related nanomaterials against the FDA regulatory framework. It will be established that for three of the four classes of nanomaterials, (31) the issues of their adverse effects on human health or the environment are nonexistent or can be adequately addressed within the existing framework. (32)
The fourth class of nanomaterials, artificial materials that have been previously approved for use in foods and food processing in bulk form and are now being reformulated for use as nanomaterials, requires the closest examination. The public health and environmental concerns of various watchdog groups, if these materials will be allowed for use without any additional testing, can be very real. A new nano-specific regulatory framework is required to adequately address these problems. However, a complete reevaluation of all these nanomaterials, or even a ban on their use as some radical groups propose, are not feasible solutions.
The suggested regulatory approach to evaluating the safety of these nanomaterials is based on the concepts of comparative risk analysis and various risk management techniques. This means that products using nanoparticles with physical properties, chemical composition, or physiological actions similar to known carcinogens or other toxic materials should be scrupulously examined first. The FDA must have the authority (1) to require that additional safety tests be performed on these materials and (2) to reject the product until it is satisfied with the results. The burden of proof should be on the manufacturer to show the safety of the product containing nanomaterials. In the absence of credible scientific evidence showing potential toxicity of the nanoparticles, the FDA should require manufacturers to perform random testing to accumulate the knowledge base.
This note will briefly address the issues of risk assessment and risk communication because they are integral parts of the risk management approach to safely using nanomaterials in food applications. However, due to the limited scope of this note, a thorough discussion of these issues is not possible.
Nanotechnology has the potential to revolutionize the food industry from agriculture to processing, distribution, and packaging. (33) It can provide many benefits to people, including more nutritious food products and longer shelf life. (34) Large food manufacturers are spending money on nanotechnology research and development of novel products and processes, harnessing the benefits of the new technology. (35) According to the Helmut Kaiser Consultancy, the nano food market is expected to be a more than $20.4 billion industry by 2010. (36)
But despite the promise of future benefits, a great controversy is currently surrounding food nanotechnology. A group of German consumers participating in the BfR Consumer Conference on Nanotechnology (37) determined foods to be "the most sensitive area for the use of nanomaterials." (38) Consumers felt strongly that the minor advantages "like changes to the flow properties of ketchup" were inessential when compared to the grave risks. (39) Similarly, watchdog groups are constantly calling for a total ban on development of new food products and processes employing nanotechnology. (40)
Several considerations play a role in this controversy regarding nanotechnology applications in food industry. First, because food products are consumed regularly, any change in food industry practices, including the use of nanomaterials, potentially concerns everyone on the planet. Second, whatever effect nanoparticles may have on human health, will be strongest if ingested directly into the gastrointestinal (GI) tract, as they are with food. Combined with the first factor, food nanotechnology can benefit or injure the entire human race as no other nanotechnology application could. Lastly, the public has historically been reluctant to accept...