Box 5-2: Ecolabels according to the ISO: the three types

Type I labels compare products with others within the same category, awarding labels to those that are environmentally preferable through their whole life cycle. The criteria are set by an independent body and monitored through a certification, or auditing, process. Ranking products in this way requires tough judgement calls: consider two otherwise identical products, one air polluting, another water polluting. Which is superior?

Type II labels are environmental claims made about goods by their manufacturers, importers or distributors. They are not independently verified, do not use pre-determined and accepted criteria for reference, and are arguably the least informative of the three types of environmental labels. A label claiming a product to be "biodegradable," without defining the term, is a type II label.

Type III labels list a menu of a product's environmental impacts throughout its life cycle. They are similar to nutrition labels on food products that detail fat, sugar or vitamin contents. The information categories can be set by industrial sector or by independent bodies. Unlike type I labels, they do not judge products, leaving that task to consumers. Critics question whether the average consumer has the time and knowledge to judge whether, for example, emissions of sulphur are more threatening than emissions of cadmium.