Microbiological resistance of MSS building materials.

The maintenance of microbiologically clean conditions within a building is facilitated if the survival of micro-organisms within it can be minimised. One way of achieving this is to ensure that any part of the fabric of the building onto which organisms might fall does not support their growth or survival.

The tests were carried out by Microbiology Laboratories, London, where clean samples of the standard component parts used in MSS buildings were inoculated with a known number of washed organisms in order to determine their ability to survive thereon. The organisms used were chosen on the basis that they represent a good cross-section of those occurring naturally in the environment and particularly likely to be encountered in biomedical and pharmaceutical laboratories.

The organisms used were Bacillus spp, Escherichia coli, Salmonella typhimurium, Staphylococcus aureus.

The density of the control inocula did not change to a significant degree after the eight hour test, indicating that the use of MSS materials in the fabrication of clean environmental enclosures is beneficial in facilitating the maintenance of these clean conditions.

Fungal tests were also carried out using Chaetomium globosum, Cladosporium cladosporoides, Paecilomyces variotii, Penicillium funiculosum and Stachybotris atra.