Solid low level radioactive waste (LLW) which arises at nuclear power stations and other nuclear facilities in the UK, is routinely transported to British Nuclear Fuels' site at Drigg in Cumbria for disposal. A requirement was identified for the use of a refurbished ISO freight container of the full-height design, to transport drummed LLW to the site of a supercompaction facility prior to disposal at Drigg. This paper describes the reasoned technical justification employed for certifying the refurbished ISO freight container, Design No. 2912B, as an IP-2 package under Paragraph 523 of the IAEA Transport Regulations and the development of a new generation of ISO freight container, Design No. 2044. It was recognised that the use of a refurbished container was only an interim measure and because of significant changes in the acceptance criteria for disposal, the increased use of high force compaction techniques and the proposed amendments to the IAEA Transport Regulations, Nuclear Electric embarked upon the development of a new generation of ISO freight containers. The new container design (Design No. 2044) incorporates a readily decontaminable stainless steel interior, a comprehensive load restraint system designed for the transport of single and multiple packages, and is lined with a polyurethane foam between the inner and outer skins. It is designed to transport 70 off, 200 litre drums of LLW (stacked in two layers) and other payloads of size not greater than 4 m long × 2 m wide and 20 tonnes in weight. The container was subjected to a range of tests to prove compliance with the ISO standard and the IAEA Transport Regulations. Following the preparation of the required documentation, in particular a Safety Case and comprehensive Operating and Maintenance Instructions, a Certificate of Regulatory Compliance was issued by the appropriate authority certifying the container as an Industrial Package Type 2 (IP-2) suitable for the transport of drummed LLW and other materials within LSA-II/SCO-II limits.