The total environment experienced by defence materiel is a combination of naturally occurring environments and induced environments.

a) Natural environments consist of those meteorological, climatic, chemical and biological conditions that materiel directly experiences at its external surfaces at its global location.

b) Induced environments consist of those mechanical, climatic, chemical and biological conditions experienced by materiel as a result of its configuration, modes of deployment, its location and its operation, and that of co-located materiel on the service platform, during the factory to final use or disposal sequence.

In practice, there will be a tendency for natural and induced environments, particularly climatic, to merge. However, similar test methods will apply and any differences can usually be accommodated by the choice of test severities.

This Part describes the range of induced climatic, chemical and biological environments likely to be encountered by materiel. It also suggests test methods that have been developed to represent the effects of induced environments. Detailed information on the characteristics and effects of natural environments is provided in Part 4. Induced mechanical environments are covered in Part 5.

This Part describes and enumerates a wide range of induced climatic, chemical and biological environments encompassing most types of materiel. Excluded are the deployment platforms themselves, eg: ship and aircraft structures, propulsion units, land vehicles and buildings, except where the materiel under consideration could be subjected to environments generated by a deployment platform.

Only environments associated with normal Service conditions are addressed in this Part. That is, information is not provided on abnormal aspects such as fire or crash conditions. Furthermore, the information provided does not cover hostile, deliberate attack by munitions or chemical and nuclear explosions. Where applicable, these conditions should be defined in the project-specific documentation. Tests for abnormal environments should be considered, in principle, in the same way as for normal environments, that is, compliance will be demonstrated by a combination of assessments and tests.

The environments arising from the effects of nuclear explosions are addressed in Def Stan 08-4. The environments arising from chemical and biological attack, the techniques for chemical and biological hardening, and the methods and materials used as decontaminants, are given in Def Stan 08-41 Part 1.

The characteristics of the induced climatic, chemical and biological environments encountered by materiel are identified in this Part by the phase in the logistical and operational sequence from its place of manufacture to its final intended use or disposal. Moreover, this Part has been structured to allow easy extraction of the information pertaining to each phase and type of deployment platform.

The information contained in this Part allows test methods to be selected and associated test severities for many induced environments to be derived, ranging from those for general application to those specific to a particular project. Where relevant, the test methods identified in this Part refer to those specified in Part 3 of this Standard.