Testing that Reaches the World

MIL 810G Method 508 Fungus testing, is performed to evaluate the resistance of equipment and materials to fungal growth, particularly in high-humidity environments. The presence of fungi can lead to material degradation, corrosion, and potential performance issues in equipment. 

Fungus testing involves subjecting equipment or material to conditions conducive to fungal growth. The test may include exposing the samples to a variety of fungal species under controlled environmental conditions, such as elevated humidity, temperature, and nutrient-rich media. Different fungal species may be used in the testing to represent typical environmental conditions where the equipment will be deployed. Common fungal strains, such as Aspergillus and Penicillium, are often included in these tests. 

The purpose of this fungus test is to assess the extent to which equipment will support fungal growth and how any fungal growth may affect performance or use of the equipment. The primary objectives of the fungus test are to determine: 

1. If the equipment, or the assembled combination of a system, will support fungal growth, and if so, of what species.
2. How rapidly fungus will grow on the equipment.
3. How fungus affects the equipment, its mission, and its safety for use following the growth of fungus on the equipment.
4. If the equipment can be stored effectively in a field environment.
5. If there are simple reversal processes, e.g., wiping off fungal growth.

The acceptance criteria for fungus testing typically involve limits on the extent of fungal growth, material integrity, and the equipment's ability to maintain performance within acceptable limits. The Clark test team will help you select the specified fungi test based on industry standards, customer requirements, or regulatory guidelines. 

Typically, our engineers and technicians will inspect to evaluate the extent of fungal growth, potential material degradation, and any impact on the performance or functionality of the equipment. Visual examination, microscopic analysis, and other testing methods may be employed for this purpose. 

Since microbial deterioration is a function of temperature and humidity, and is an inseparable condition of the hot, humid tropics and the mid-latitudes, consider it in the design of all standard, general-purpose material.  This method is used to determine if fungal growth will occur and, if so, how it may degrade/impact the use of the material. 

The duration of the fungi test is typically twenty-eight days which is the minimum test period to allow for fungus germination, breakdown of carbon-containing molecules, and degradation of material. Since indirect effects and physical interference are not likely to occur in the relatively short time frame of the fungus test, consider extension of the exposure period up to 84 days if a greater degree of certainty (less risk) is required in determining the existence or effect of fungus growth. 

Regarding the choice of fungus for the test, the fungi commonly used are listed in table below. These organisms were selected by the MIL Standard Method because of their ability to degrade materials, their worldwide distribution, and their stability. These organisms have, where possible, been identified with respect to the materials to which they are known to attack.  

US Test Fungus. 

 

Fungus	Fungus Sources Identification No.1		Materials Affected
	USDA2/	ATCC3/
Aspergillus flavus	QM 380	ATCC 9643	Leathers, textiles, rubber. Electrical insulation, varnish, wax, packing materials, etc.
Aspergillus versicolor	QM 432	ATCC 11730	Leather, adhesives, textiles, automotive components such as gaskets, distributors, cables, hoses, PVC, breakers, solenoids, switches
Penicillium funiculosum	QM 474	ATCC 11797	Textiles, plastics, cotton fabric, polymers, automotive components such as gaskets, distributors, cables, hoses, PVC, airborne equipment such as breakers, solenoids, switches, remote transmission accessories
Chaetomium globosum	QM 459	ATCC 6205	Cellulose and any components containing paper and paper products such as packing materials, textiles, polymeric hydrocarbons and some synthetic polymeric materials
Aspergillus niger	QM 386	ATCC 9642	Textiles, vinyl, conformal coatings, insulation, leather, etc.; resistant to tanning salts

 

The test engineering team at Clark Testing can help ensure that your equipment will operate, function, and maintain its performance after withstanding an elevated level of fungi due to its operating environment.  Call or email the Clark Dynamics Test Laboratory for assistance in developing a test plan and conducting the appropriate test to validate your equipment in accordance with MIL-STD-810G Method 508.6.