GB/T 2423.16:2022 Environmental testing - Part 2: Test methods - Test J and guidance: Mould growth
1 Scope
This document provides a test method for determining the extent to which electrotechnical products support mould growth and how any mould growth may affect the performance and other relevant properties of the product.
Since mould growth conditions include high relative humidity, the test is applicable to electrotechnical products intended for transportation, storage and use under humid conditions over a period of some days at least.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
No terms and definitions are listed in this document.
4 General description
4.1 Background
Under certain climatic and environmental conditions, micro-organisms may settle on and colonize the surface of electrotechnical equipment. Their presence or their metabolic products may not only damage the equipment itself, but may also affect the equipment’s operability and serviceability. The actions of micro-organisms on equipment are influenced by two different processes: direct action in which the deterioration of material serve as a nutritive substance for the growth of the micro-organisms and indirect action in which the metabolic products of the micro-organisms generate deterioration.
The preferred method for controlling the effects of micro-organisms is by the selection of materials that do not promote growth. Also acceptable is the treatment, or hermetic sealing, of potentially vulnerable materials and components. Additionally, equipment may not need to be evaluated if it is stored and/or operated throughout its entire life, in conditions unlikely to encourage the growth of micro-organisms. Only if these cannot be achieved is it usually necessary to demonstrate the resistance of complete or partial equipment by testing.
The test procedures and severities of this document are most commonly used to evaluate the resistance of complete or partial equipment, to the damaging effects due to the presence of micro-organisms and their metabolic products. Testing of entire equipment is usually necessary if it is critical that performance be demonstrated after exposure to adverse temperature/humidity conditions that would support the growth of micro-organisms.
An alternative approach which is sometimes used is to consider only the individual materials of which an equipment is composed. This alternative approach may be particularly relevant when the primary concern is with deterioration of structural materials of the equipment rather than its operability and serviceability. In such cases, individual materials may need to be evaluated, only if previous evidence exists as to its resistance to the effects of growth of micro-organisms. The testing procedures in ISO 846:2019 are essentially the equivalent of those set out in this document but applied to specimens comprising samples of material.
Some materials can, when buried in natural soil that has a water holding capacity, exhibit significant degradation in structural characteristics. The evaluation of such conditions are not included in this document. However, should the evaluation of material be required, Method D (soil-burial test) in ISO 846:2019 is suggested. Similarly, if it is necessary to evaluate a material’s resistance to biological growth, Method C (resistance to bacteria) in ISO 846:2019 is suggested.
Foreword II
Introduction IV
1 Scope
2 Normative references
3 Terms and definitions
4 General description
5 Health hazards to operators
6 Description of the test variants
7 Reagents and materials
8 Description of test apparatus
9 Severities
10 Initial examinations
11 Pre-conditioning
12 Conditioning
13 Final examinations
14 Information to be given in the relevant specification
15 Information to be given in the test report as a minimum
Annex A (Informative) Danger to personnel
Annex B (Nominative) Inoculation methods (See 12.2)
Annex C (Informative) Recommended safety precautions
Annex D (Informative) Decontamination procedures
Annex E (Informative) Information on the test fungi
Annex F (Informative) Guidance
Annex NA (Informative) The components of GB/T 2423
Bibliography
Figure B.1 Aerosol inoculation method (AIM)
Table 1 Test fungi
Table 2 Test reagents
Table E.1 List of identical strains
Table E.2 List of recommended nutritive media for maintaining the cultures
