The concept of substantial equivalence, introduced for the risk assessment of genetically modified (GM) food, is a reducing concept because it ignores the context in which these products have been produced and brought to the consumer at the end of the food chain. Food quality cannot be restricted to mere substance and food acts on human beings not only at the level of nutrition but also through their relationship to environment and society. To make this context explicit, I will introduce an ``equivalence scale'' for the evaluation of food chains (GM or not GM). By contrast with substantial equivalence, which involves mainly quantitative, analytical methods of evaluation, ``qualitative equivalence'' refers to ``less'' or non-substantial factors that require new methods of evaluation based on qualitative principles. ``Ethical equivalence'' refers to factors that show the moral value contained in food products. To analyze the different levels at which ethics is needed in food chains, I will use the French principles: ``Liberty, Equality, Fraternity,'' or freedom, equality, solidarity, and add a fourth principle: sustainability. Sustainability, solidarity, and freedom can be applied to the evaluation of environmental, socio-economic, and socio-cultural ethical equivalence, respectively. Equality refers to justice and should operate so as to guarantee that sustainability, solidarity, and freedom are satisfied. I suggest that ethics can provide a basis for a renewal of the food chain concept. Besides Quality Assurance, it is now essential to develop an ``Ethical Assurance'' and this equivalence scale could provide a basis to set up ``Ethical Assurance Standards'' (EAS) for food chains.