The Animals (Scientific Procedures) Act 1986, sometimes referred to as ASPA, is an Act of the Parliament of the United Kingdom (1986 c. 14) passed in 1986, which regulates the use of animals used for research in the UK. The Act permits studies to be conducted using animals for procedures such as breeding genetically modified animals, medical and veterinary advances, education, environmental toxicology and includes procedures requiring vivisection, if certain criteria are met. Revised legislation came into force on 1 January 2013. The original act related to the 1986 EU Directive 86/609/EEC which was updated and replaced by EU Directive 2010/63/EU In 2002, a Government select committee inquiry described the Act as the "...tightest system of regulation in the world" in relation to the regulation of using animals for research. Background Prior to ASPA, the use of animals in the UK was regulated by the Cruelty to Animals Act 1876, which enforced a licensing and inspection system for vivisection. Animal cruelty was previously regulated by the Protection of Animals Act 1911 (now largely repealed) and more recently by the Animal Welfare Act 2006, both of which outlaw the causing of "unnecessary suffering". Specific exemptions apply to experiments licensed under the 1986 Act. History and scope The 1986 Act defined regulated procedures as animal experiments that could potentially cause "pain, suffering, distress or lasting harm", to protected animals, which encompassed all living vertebrates other than humans, under the responsibility of humans. A 1993 amendment added a single invertebrate species, the common octopus (Octopus vulgaris), as a protected animal. The Act applied only to protected animals from halfway through their gestation or incubation periods (for mammals, birds and reptiles) or from when they became capable of independent feeding (for fish, amphibians, and the common octopuses). Primates, cats, dogs and horses had additional protection over other vertebrates under the Act. Revised legislation came into force on 1 January 2013. The Act has been expanded to protect - The definition of regulated procedures was expanded to - ASPA also regulates the modification of genes in protected animals if this causes the animal pain, suffering, distress or lasting harm. Other considerations in the Act include animal sources, housing conditions, identification methods and the humane killing of animals. This legislation is widely regarded as the strictest in the world protecting animals used in research. Those applying for a license must explain why such research cannot be