Interior coatings and plastics which have mold and bacterial resistance properties are important for the environments with high humidity levels and temperature changes. Two important standards ASTM D3273 and ISO 22196 are used to evaluate the effectiveness of coatings and plastics in resisting mold and bacteria. It is necessary for manufacturers to understand these standards to make sure that their products meet regulatory requirements. This article aims to provide a comparative analysis of ASTM D 3273 and ISO 22196 with a focus on test methods, test conditions, test strains and their applications.

ASTM D3273 

ASTM D3273 Standard provided a test method for the evaluation of mold resistance of interior coating and paints under controlled conditions. This standard is used for coating used in interior environments where the growth of mold can lead to structural damage as well as other health issues.

ISO 22196 

ISO 22196 developed by the International Organisation for Standardization (ISO), specifies a method to measure the antibacterial activity of plastics and other non-porous surfaces. 

ASTM D3273 and ISO 22196 are standardized methods to ensure that the results obtained from testing are consistent, reproducible and comparable across different labs. This uniformity in results is important for regulatory compliance.

Differences between ASTM D 3273 and ISO 22196

Origin of standard

• ASTM D 3273 was developed by ASTM International (American Society for Testing and Materials) and is accepted regionally. ISO 22196 developed by the International Organisation for standardization, is a globally recognised standard. This difference in origin reflects the regional versus global focus of these standards.

Scope of products

• ASTM D3273 provides guidelines for testing of products which include antifungal interior coatings, paint and other surface finishes.

• ISO 22196 standard is for testing antibacterial-treated plastics and other non-porous materials.

Mandatory test strains

• The mold strains specified in ASTM D 3273 standard include Aureobasidium pullulans, Aspergillus niger, and Penicillium species. 

• Staphylococcus aureus and Escherichia coli are mandatory test strains as per ISO 22196 standard. 

Controlled conditions

• ASTM D3273 specifies specific temperature and humidity levels for mold growth while ISO 22196 specifies these conditions for bacterial growth.

Testing method

• ASTM D3273- In this method the treated material is exposed to a controlled humid environment and specific strains of mold for a particular period of time. The materials are then evaluated based on the degree of mold growth observed.

• ISO 22196 – This test method involves the inoculation of specific bacterial strains on the test sample and then incubating them for a period of 24 hrs. After incubation, the reduction in bacterial count is estimated to determine the antibacterial efficacy of the material.

Selecting the Right Standard

Manufacturers of interior coatings and antibacterial plastics must consider the type of material and its application before deciding the test method. ASTM D 3273 is developed for testing interior coatings for evaluating mold resistance. ISO 22196 is for testing plastic products that are treated with antibacterial agents to ensure that they are effective in reducing bacterial contamination.

At Microbial Investigations Switzerland (MIS), we specialize in providing comprehensive testing and validation services to ensure your products meet the highest standards of microbial resistance. Whether you’re dealing with interior coatings requiring mold resistance testing or antibacterial-treated plastics, our state-of-the-art laboratories and experienced microbiologists are here to help. Trust MIS for precise and reliable results that will enhance your product’s performance and compliance with international standards.

Contact us today to learn how our specialized services in ASTM D 3273 and ISO 22196 testing can benefit your business.