ISO 9022-11:2015 outlines methods for environmental testing of optical instruments and their components, including mechanical, chemical, and electronic parts, to evaluate their resistance to mould growth. Typically, the standard is used for testing representative samples such as mounted optics, material samples, or surface coatings, rather than complete instruments or assemblies, which are only tested under exceptional circumstances.

The primary goal of these tests is to assess how well materials and components withstand environments that promote mould growth. This standard is not intended for routine production control but rather for determining how mould growth impacts various performance characteristics, including optical, climatic, mechanical, chemical, and electrical properties.

Additionally, ISO 9022-11:2015 evaluates the potential effects of metabolic by-products from fungi, such as enzymes or acids, which could lead to damage like etching, corrosion, or short-circuits on components such as printed circuit boards.