Risk analysis of food additives

Additives are used in foods to perform a variety of functions, many of which are described elsewhere in this book. The use of additives is intended to provide some benefit to the consumer such as improved shelf life, taste or texture. However, where additives are used in foods, the public is entitled to expect that they will not be exposed to unacceptable risks should they consume such foods. This chapter is devoted to describing risk assessment methods that are applied at national and international levels. 

Any reliable system for assessing and controlling chemical risks must contain six key elements whose relationships are described in Fig. 4.1  

Hazard identification. It is necessary to be aware of what chemicals might be used as additives in a particular foodstuff and the nature of the harmful consequences to human health that might be associated with them. 

Dose-response characterisation. Different chemicals will be associated with different toxicological end-points and the risk of any individual experiencing toxicity is related to the dose that they receive. Very often it is possible to identify a dose level below which the probability of anyone experiencing an adverse effect is veiy low or zero. For additives this is usually referred to as the Acceptable Daily Intake (ADI). 

Exposure analysis. The amount of any chemical that an individual is exposed to will depend upon the levels that occur in food and the amounts of those foods that are consumed. Different population groups will often have different levels of exposure and it is therefore necessary to identify such sub-groups. The exposure level for additives is frequently referred to as the Estimated Daily Intake (EDI). 

---

Tennant, D.R., Risk analysis of food additives, in Food Chemical Safety, Volume 2 Additives, Watson, D.H., Ed., Woodhead Publishing, Cambridge, U.K., 2002, 61. 

The Food Standards Code [10] is the main regulatory instrument which controls the quality of food, contaminant levels, approved additives, processing aids, sanitisers and disinfectants and these standards are performance based. If a chemical or a group of chemicals is covered by a food standard then they must only be used in food in accordance with the standard. However, if a chemical is not mentioned in a standard, then this does not preclude its use in food. For a new chemical not previously used in food production, it would be necessary for the supplier to undertake a detailed risk analysis of the product to demonstrate its safety and suitability. The assessment would need to consider both the toxicological profile of the chemical and the levels of human exposure that are likely to arise from residues in food. 

Tools should be developed to support the identification of mixture exposure situations that may cause unexpectedly high risks compared to the standard null models of concentration addition and response addition, for example, based on an analysis of food consumption and behavioral patterns, and the occurrence of common mixture combinations that cause synergistic effects. Criteria should be developed for the inclusion of interaction data in mixture assessments. 

This volume provides comprehensive information about additives in the food industry. The book opens with an explanation of risk analysis and analytical methods in relation to the use of additives in food products. This is followed by full details of relevant EU and USA regulations. The second part of the book provides information about specific subjects including flavourings, sweeteners and colourings. 

As discussed in FDA s Preparation of Food Contact Notifications for Food Contact Substances Toxicology Recommendations (FDA, 2002), FDA has set forth minimum testing recommendations for tiered levels of expected consumer exposure. These recommendations are based on the general principle that the potential risk is likely to increase as exposure increases. In addition, submitters are encouraged to discuss the structural similarity of their food contact material or its constituents to known mutagens or carcinogens. This analysis is termed structure-activity relationship (SAR) analysis and is recommended for all exposures (discussed further below). Table 7.1 summarizes... 

To date, JMPR has evaluated 240 pesticides, many of them repeatedly. JMPR establishes ADIs (based on chronic toxicity) and acute reference doses (based on acute toxicity) on the basis of the toxicological data and related information available on the substances that are being evaluated. In addition, JMPR reviews pesticide use patterns, data on the chemistry and composition of pesticides, and methods of analysis of pesticide residues. It recommends MRLs for pesticides that occur in food commodities following their use according to Good Agricultural Practice. The potential intake of pesticide residues is compared with the ADI and acute reference dose to estimate the potential dietary risks associated with the adoption of the MRLs. 

---