Lead compounds which, when mixed in a ratio of 1:1000 with 0.07M hydrochloric acid and stirred for one hour at a temperature of 23 °C ± 2 °C, exhibit a solubility of 5 % or less (see ISO 3711:1990 "Lead chromate pigments and lead chromate - molybdate pigments - Specifications and methods of test") are considered insoluble and are not subject to the requirements of ADR unless they meet the criteria for inclusion in another class.