ISO 3999:2004 specifies the performance, design and test requirements of apparatus for gamma radiography with portable, mobile and fixed exposure containers of the various categories defined in Clause 4.

It applies to apparatus designed to allow the controlled use of gamma radiation emitted by a sealed radioactive source for industrial radiography purposes, in order that persons will be safeguarded when the apparatus is used in conformity with the regulations in force regarding radiation protection.

It is emphasised, however, that so far as transport of apparatus and sealed radioactive source is concerned, compliance with ISO 3999:2004 is no substitute for satisfying the requirements of relevant international transport regulations (IAEA Regulations for the safe transport of radioactive materials: IAEA-STI-PUB 998, Safety Standards Series ST-1 and ST-2, and/or the relevant national transport regulations).

The operational use of apparatus for industrial gamma radiography is not covered by ISO 3999:2004. Users of this equipment shall comply with national regulations and codes of practice.