To become range certified, different sizes of Locked4Kids cartons were tested by the testing facilities of BVI in Belgium, a ISO 17025 certified institute. Tests with children usually takes place at infant schools and playgrounds and involves between 50 and 200 children per test. In isolated groups of 2, children are instructed to try to open the packaging, even by using their teeth if they like. Than they get 5 minutes to open the packaging spontaneously.
After the first 5 minutes a close distance demonstration on how to open the packaging is given by an auditor. Immediately after demonstration children get another 5 minutes to try to open the carton. To pass the test, no more than 15% of openings is allowed during the first 5 minutes and no more than 20% during 10 minutes.