Resistance of Plastic to Bacteria

It is actually difficult to achieve bacterial colonisation on the surface of most plastics without soiling, especially 

Coli Staph. Aureus Ps. Aeruginosa Candida albicans Rhodotorula rubra 

Plastic film with test method ISO 846 C (a.5) with a variety of different organisms, including some yeast 

2 AATTC 147 2004 Antibacterial Activity Assessment of Textile Materials Parallel Streak Method (a. 14) 

This is a method originating from the textile industry but is sometimes also used as a base for testing textiles or other substrates coated with PVC or PU. A swab of pure bacteria, usually Staphyloccocus aureus or Klebsiella sp., but others can also be used, is drawn across nutrient agar in five parallel lines. The sample for testing is then intimately placed across the five streaks. If the biocide migrates from the sample, it will prevent growth of the bacterium near the edge and under the sample itself. 

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ASTM G22, Recommended Practicefor Determining Resistance of Plastics to Bacteria, Vol. 14.02, ASTM, Philadelphia, Pa., 1990. 

ASTM G 22-76 (1985) Standard Practice for Determining Resistance of Plastics to Bacteria, 4 pp (Com G-3)... 

G22-76 Standard practice for determining resistance of plastics to bacteria... 

Test method for dynamic mechanical properties of plastics by means of a torsional pendulum Practice for determining resistance of synthetic polymer material to fungi. Practice for determining resistance of plastics to bacteria... 

ASTM G 22, Resistance of Plastics to Bacteria The test protocol is similar to G 21 specimens are inoculated (usually) with Pseudomonas aeruginosa, an opportunistic soil bacterium that is a hazard to immune-compromised persons. The zone of inhibition is sometimes determined. This should not be combined with fungus resistance testing, as Pseudomonas can metabolize a variety of fungi (instead of the biocide-containing nutrient). 

It is effectively impossible to accelerate biological attack substantially. ISO 846 [44] defines laboratory methods for determining the resistance of plastics to fungi and bacteria, while BS 6085 Section 2 [45] and EN 12225 [46] are soil burial methods for... 

Exposure to living organisms is a biological rather than a physical test and is normally entrusted to specialist laboratories. A British standard for pipe joint rings [4] includes a requirement for resistance to microbiological degradation, and there is an ISO standard for re,sistance of plastics to fungi and bacteria (5). 

The resistance of plastic materials to attack by microorganisms (mold, fungi, and bacteria) depends not only on the chemical composition of the plastic, but also on the composition and amount of filler and additives as well as on relative ambient humidity. Additives serve as food for microorganisms, thus enabling attack on plastics that are inherently resistant. 

This accelerated laboratory test is somewhat similar to the test to determine resistance of plastic material to fungi. The bacterial cell suspension in place of the fungus spore suspension is used to study the effect. The test is conducted in a similar manner by spraying the bacterial cell suspension onto the specimen placed in a petri dish covered with nutrient salts agar. The incubation is carried out for a minimum of 21 days under specified conditions in the incubator. A variation of the standard method is sandwiching the sample between two equal lots of nutrient salts agar and then spraying the bacterial cell suspension on it. This variation provides a more extensive contact between the test bacteria and the specimens. 

OUTDOOR EXPOSURE TEST FOR STUDYING THE RESISTANCE OF PLASTIC MATERIALS TO FUNGI AND BACTERIA AND ITS LIMITATIONS... 

Plastic pipes, even when flushed out with the most powerful disinfectants and germicides, have proven to be safe havens for some bacterial strains. Bactena-resistant piping is of major importance in pharmaceutical manufacture, Research is underway to find plastic piping that will reject the adhesion of bacterial slimes. Currently, alloy steels are widely used. The adherence of slimes to plastic pipes permits colonies of bacteria to multiply. A similar problem exists when patients are furnished with plastic implants orprosiheses Hospital water supplies must be continuously monitored. 

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