40. The non-fixed contamination on the external surface of any package shall be kept as low as is practicable and, under routine conditions of transport, shall not exceed 4 Bq/cm2 for beta and gamma emitters and low toxicity alpha emitters, and 0.4 Bq/cm2 for all other alpha emitters.
41. The limits specified in Article 40 are applicable when averaged over any area of 300 cm2 of any part of the surface.
42. In the case of a freight container, an overpack, tanks or intermediate bulk container, the level of the non-fixed contamination on the external or the internal surfaces shall not exceed the limits as specified in Article 40.
43. Article 42 shall not apply to the internal surfaces of freight containers being used as packagings, either loaded or empty.