Apart from the potential costs to industry and the complexity of the new law, REACH has also attracted concern because of animal testing. Animal tests on vertebrates are now required but allowed only once per each new substance and if suitable alternatives cannot be used. If a company pays for such tests, it must sell the rights of the results for a "reasonable" price, which is not defined. There are additional concerns that access to the necessary information may prove very costly for potential registrants needing to purchase it.