as those advanced by CropLife International in their Responsible Use manual. Labels or printed packaging may include Braille to aid users with visual impairment. Criticism of label readability is not uncommon; for example, Canadian researchers found that medicine labels did not consistently follow legibility guidelines. In some countries and industries, for example the UK (food) and EU (medicines) label guidelines are not legally binding (the latter using phrases such as "The type size should be as large as possible to aid readers...") and thus are unenforceable. On the other hand, countries may stipulate legal minima for readability, such as the USA's FDA on nutritional information and Australia/New Zealand's code for food labels and packs. Environmental considerations Compliance Labels of sustainability standards and certification such as organic food and energy efficiency class labels are often intended to confirm compliance with relevant social and environmental considerations, enabling consumers and other purchasers to make more ethical decisions in terms of the environmental impact of products. Labels such as the European Eco-label and those issued by sustainability standards organisations may be used by businesses and public bodies to confirm compliance. Public procurement regulations in the European Union and the United Kingdom require that label requirements only include those which are "linked to the subject-matter of the contract". The approach of labels can involve a trade-off between financial considerations and higher cost requirements in effort or time for the product-selection from the many available options. Impact of labels on the environment Labels may affect the environment during manufacture, use, and post-use. Choice of backings, coatings, adhesives and liners can be strong factors. Environmental regulations and guidelines can come from many sources. Users of labels on packaging may consider some of the sustainable packaging guidelines. Based on the solid waste hierarchy, the quantity and size of labels should be minimized without reducing the necessary functionality. The material content of a label should comply with applicable regulations. Life cycle assessments of the item being labeled and of the label itself are useful to identify and improve possible environmental effects. For example, reuse or recycling are sometimes aided by a label being removable from a surface. If a label remains on an item during recycling, a label should be chosen which does not hinder the recyclability of the item. For example, when labeled corrugated boxes are recycled, wet strength paper labels do not hinder box recycling: the PSA