On 5 January 2011, the European Food Safety Authority (EFSA) endorsed for public consultation its draft guidance on risk assessment concerning potential risks from applications of nanoscience and nanotechnologies to food and animal feed. Stakeholders and interested parties have the opportunity to comment on the guidance until 25 February 2011.

Building on EFSA’s previous scientific opinion of February 2009 on the potential risks associated with nanoscience and nanotechnology in food and feed applications, the purpose of the present guidance is to provide risk assessors, regulators and other stakeholders with practical advice on a risk assessment methodology for engineered nanomaterials used in food and feed.

The draft document represents the first regulatory guidance on risk assessment of engineered nanomaterials used in food and animal feed, and covers all potential applications, including food additives, enzymes, flavourings, food contact materials, novel foods, feed additives and pesticides. The EFSA guidance distinguishes between risk assessment of nanomaterials concerning (i) products/applications intended for consumption by humans or animals, (ii) agrochemicals used in plant production, and (iii) products coming into contact with food/feed.

For the assessment of a nanoscale material used in food and feed applications, where the non-nanoform (i.e., ‘bulk form’) of the substance is approved for the same intended use, the guidance outlines the additional data needed to address potential intrinsic hazards that may arise from the nanoform. The supplementary data criteria include in vitro genotoxicity tests; information on absorption, distribution, metabolism and excretion (‘mechanistic studies’); and a 90-day oral rodent toxicity study. Additional in vivo data requirements may be triggered ‘depending on the outcome of these studies and on the comparison with data on the non-nanoform.’ One such criterion is for an additional toxicity study with an animal species that is phylogenetically different from a rodent (e.g., rabbit, dog, pig, non-human primate), which is similar to the data requirements under the US Environmental Protection Agency’s Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). To register an active ingredient in an antimicrobial product for food uses, FIFRA requires two 90-day animal studies with a rodent and non-rodent species. Depending on the results of these Tier 1 studies, FIFRA may also require a one-year non-rodent oral toxicity study. Despite animal welfare concerns, there are several compelling scientific reasons (in addition to regulatory requirements) to rely on in vivo studies to assess the potential toxicity of nanoscale materials.

In the case where the engineered nanomaterial in question ‘persists in the food/feed matrix and in gastrointestinal fluids and has no approved non-nanoform application’, then relevant EFSA testing guidelines for its intended application should be used following certain modifications as outlined in the guidance. The issue of test modifications is largely one of kinetics and the appropriate adjustments to measurement and testing protocols to ensure the most relevant and useful information is collected. This is reflected in the EFSA statement: ‘Some test models and standard testing protocols used for non-nanoform substances may not necessarily be appropriate or optimal.’

The guidance appears to be an initial reasoned approach that takes many thoughtful areas into consideration, such as the need to explore alternative dose metrics, the local interaction between material properties and chemical properties at the target site and the resultant kinetics, a focus on non-soluble and non-biodegradable materials, bioavailability issues specific to the food/feed matrix and route of exposure, and the confounding effects often found at very high testing doses. EFSA points out that existing conventional risk assessment paradigms should be sufficient in most cases, and states: ‘A loss of nano-specific properties will move the risk assessment into a conventional risk assessment and the nano-specific risk assessment procedure will no longer apply.’

Using these testing guidelines and risk assessment strategies as a baseline allows for greater regulatory certainty; however, the decision-making agencies will continue to rely on industry to provide high-quality information for risk assessment (some of which will be considered confidential). Collectively, these decisions require much thought and attention up front to identify the most relevant concerns and how best to address them without sacrificing one’s competitive position in the market.