Antimicrobial plastics are plastics that are impregnated with antimicrobial agents to prevent the growth of microorganisms. Having a knowledge of how these plastics resist microbial growth is important, particularly in industries where the need for sanitation and durability are of utmost importance. In this article two major standards—ISO 846 and ASTM G21 which are used globally to evaluate the resistance of plastic materials against fungi and bacteria will be discussed. We will explore their similarity and differences, and why these tests are important for the development of antimicrobial plastics.
ISO 846 Standard
ISO 846 test method is used for assessing the resistance of plastics to microorganisms. This method can be used to test the effects of fungi, bacteria and other microorganisms on plastic surfaces. It determines if the material of the plastic serves as a source of nutrients required for the growth of microorganisms which can lead to the degradation of plastics.
ASTM G21 Standard
ASTM G21 outlines procedures to evaluate the resistance of synthetic polymeric materials to fungal growth. This standard is used to determine the susceptibility of materials to fungal growth by assessing visible effects and physical property changes.
Similarities
Objectives
The aim of ISO 846 and ASTM G21 is to evaluate the resistance of polymeric materials to microbial growth. They provide standard test methods to ensure consistent and reliable test results. They help to identify materials that can withstand microbial attack and maintain the material structure when exposed to various environments.
Scope of products
ISO 846 and ASTM G21 tests can be used for testing a wide range of antimicrobial plastics, including films, sheets, and molded articles. This also includes unmodified plastics and those treated with additional agents to enhance their microbial resistance.
Differences
Origin of standards
ISO 846 was developed by the International Organization for Standardization. It is an internationally accepted standard. It is more commonly used in European countries.
ASTM G21 was developed by ASTM International and is widely used in North America.
Mandatory test strains
ASTM G21 employs the following mandatory fungal test strains – Aspergillus niger; Penicillium pinophilum, Chaetomium globosum, Gliocladium virens, Aureobasidium pullulans
ISO 846 includes fungal strains like Aspergillus niger, Penicillium funiculosum, Paecilomyces variotii, Gliocladium virens, Chaetomium globosum and bacterial strains like Pseudomonas aeruginosa
Regional regulatory compliance requirements
ISO 846 test is required for antimicrobial plastics intended to be marketed in European countries while ASTM G21 is required for products to be marketed in North America. Manufacturers who aim to market their products globally are required to be aware of these regional requirements to ensure compliance and market access.
Selecting the right standard
Factors such as the nature of the plastic material, the organisms against which the product is being tested, and other regulatory requirements should be considered before making a choice on the testing method. The choice of test method also depends on the target market. International markets may require compliance with both standards while the American market prefers ASTM G21 specifically for market release.
At Microbe Investigations Switzerland (MIS), we specialize in comprehensive microbial testing to ensure your polymeric materials can withstand the rigors of microbial attack. Our state-of-the-art laboratories and expert microbiologists provide precise and dependable testing services, adhering to both ISO 846 and ASTM G21 standards. Don’t leave your product’s durability to chance. Contact MIS today to validate and enhance the microbial resistance of your materials, ensuring they meet global standards and exceed market expectations. Trust MIS for all your testing and validation needs.
