ISO 9022-11:2015

Overview

ISO 9022-11:2015 - Optics and photonics: Environmental test methods - Part 11: Mould growth specifies laboratory procedures to evaluate how optical components and representative specimens resist mould (mold) contamination. The standard targets materials, mounted optics, coatings and other representative samples rather than routine production checks. Tests are intended to support material and component selection for optical instruments and assemblies expected to operate in environments conducive to fungal growth (e.g., tropical or high‑humidity locations).

Key topics and technical requirements

• Test objective: Determine how mould growth affects optical, climatic, mechanical, chemical and electrical (including electrostatic) performance of specimens. Also assess damage from fungal metabolic products (enzymes, acids) that can etch surfaces, corrode materials or cause short‑circuits on PCBs.
• Test specimens: Complete instruments are tested only in exceptional cases; normally representative samples (mounted optics, material coupons, surface coatings) are used.
• Test organisms: A defined list of fungal species commonly found on optical surfaces is specified for testing; fungal strains used must be recorded in test reports.
• Spore preparation: Procedures for preparing pure and mixed fungal spore suspensions are specified, including culture age limits, washing, dilution and use on the day of preparation.
• Environmental control: Use of incubation cabinets or climatic chambers, control strips (nutrient‑impregnated filter papers) and specified nutrient/mineral salt solutions to ensure reproducible exposure conditions.
• Procedure stages: Conditioning, exposure, recovery and evaluation steps are defined, plus acceptance criteria for determining suitability of materials.
• Safety and competence: The standard warns about biological hazards and recommends testing be conducted by experienced microbiological laboratories with trained personnel.

Practical applications

• Material selection and qualification for optical systems intended for humid, tropical or otherwise fungal‑prone environments.
• Evaluation of surface coatings, adhesives, sealants and printed circuit boards for susceptibility to mould and to fungal metabolic damage.
• Pre‑qualification testing for military, aerospace, medical imaging, surveillance, maritime and outdoor optical equipment where long‑term reliability against biological contamination is critical.
• Guidance for R&D, environmental testing labs and quality engineers developing mitigation strategies (coatings, fungicidal treatments, sealing) to improve service life.

Who should use this standard

• Optical component and instrument manufacturers
• Environmental and microbiological test laboratories
• Materials scientists and reliability engineers
• Procurement and compliance teams specifying environmental resistance

Related standards

• ISO 9022 series (Part 1: Definitions and extent of testing; Part 2: Cold, heat and humidity; Part 9: Solar radiation and weathering, etc.), which provide complementary environmental test methods for optics and photonics.

Keywords: ISO 9022-11:2015, mould growth, mould testing, optics and photonics, environmental test methods, fungal spore suspension, control strips, optical instrument reliability.