Directive 2006/114/EC on misleading and comparative advertising (e-link) notably lays down the conditions under which comparative advertising is permitted (Article 1). Article 4 of this Directive sets out the criteria under which comparative advertising is allowed. These criteria apply to advertisements which compare the environmental impact or benefit of different products.
Under this Directive, such a comparison should therefore, among other things:
As regards environmental comparison, national enforcers and self-regulation bodies usually interpret this criterion to mean that the comparison should refer to the same product category.
It should also be clear from the trader's claim whether the comparison is made as against one or more of the following: