Almost all countries have legislation for the protection of the health and safety of their human, animal and plant populations. The basic objective of these laws and regulations is to prevent introduction and spread of human, animal and plant diseases, to ensure adequate sanitary conditions and minimum health standards in units producing food and other articles for human and animal consumption, and to protect consumer interests by prohibiting the sale of unwholesome and contaminated food. However, such regulations may be structured so that deliberately or inadvertently they act as a barrier to trade, by being unreasonable or unnecessarily restrictive, inconsistent with regulations in other countries, or requiring excessive amounts of documentary evidence.