ISO 22196 Measurement of Antibacterial Activity on Plastics and Other Non-Porous Surfaces

Antibacterial materials and products have gained widespread and rapid acceptance by consumers because they fulfill a relatively new function, distinct from traditional material protection. Antibacterial products manufactured by adding an antibacterial agent (biocide) can suppress bacterial growth on product surfaces when conditions exist for bacterial growth. They can keep surfaces clean and hygienic and have the added benefit of minimizing environmental impact by minimizing the spread of the agent.

This technology is crucial for quality of life not only in developed but also in developing countries. Antibacterial products are widely used in plastics, coatings, ceramics, natural and artificial leather, stainless steel, and rubber.

The products covered a variety of categories, including electrical appliances, personal items, household goods, grooming products, pet accessories, and aircraft interiors. The scope of the first edition of this standard was limited to plastic surfaces. However, subsequent updates have expanded the scope to include surfaces made of other non-porous materials.

The standard “ISO 22196 Measurement of antibacterial activity on plastics and other non-porous surfaces” published by the International Organization for Standardization (ISO) describes the method for evaluating the antibacterial activity of antibacterial treated plastics and other non-porous product surfaces (including intermediate products).

This standard is not intended to be used to evaluate the effects and spread of bacteria on non-porous surfaces that have not been treated with antibacterial agents. ISO 846 describes tests for evaluating the effects and spread of bacteria on non-porous surfaces that differ from those covered by this standard.

Furthermore, secondary effects of antibacterial treatments, such as the prevention of biodegradation and odor, are outside the scope of this standard, and it is not intended to be used as a method for documenting the biodegradability of, for example, plastic materials.

In the case of plastics, biodegradation is addressed in ISO 14851, ISO 14852 and ISO 14855 and similar standards.

This standard does not cover the following products:

• Building materials, unless they are used in the same way as processed products
• Antibacterial treated textile products, even if their surfaces are coated or laminated
• Photocatalytic materials and products

The results obtained with this standard indicate antibacterial activity under the stated experimental conditions and do not reflect activity under other conditions where various factors such as temperature, humidity, different bacterial species, nutrient conditions must be taken into account.

For the purposes of this standard, the following terms and definitions apply:

• Antibacterial: An expression that describes the situation in which bacterial growth is suppressed on product surfaces or the effect of a substance that suppresses bacterial growth on product surfaces.
• Antibacterial agent: A substance used as a surface treatment or compound ingredient that prevents bacterial growth on product surfaces.
• Antibacterial activity: It is the difference between the logarithm of the number of viable cells in an antibacterial-treated product and an untreated product after bacterial inoculation and incubation.
• Antibacterial activity: It refers to the ability of an antibacterial agent to inhibit bacterial growth on the surface of materials treated with an antibacterial agent and is determined by the antibacterial activity value.

Both of the following bacterial strains should be used in their tests:

• Staphylococcus aureus
• Escherichia coli

The bacterial strains to be used are listed in the table provided in the standard. If bacterial strains obtained from culture collections other than those shown in the table are used, they must be obtained from the relevant international organizations and must be the same strains as those shown in the table. Stock cultures of these species must be prepared in accordance with the supplier's instructions. Other strains may be used if necessary; in such cases, the strain and reason for use must be included in the test report.

The ISO 22196 standard is based on the JIS Z 2801 "Testing Antimicrobial Activity of Plastics" standard published by the Japanese Industrial Standards Organization (JIS). These two standards are essentially identical. JIS Z 2801 also includes an antimicrobial surface method for testing antimicrobial activity and effectiveness.

In environments where hygiene is critical, such as hospitals, food processing facilities, and consumer goods manufacturing, understanding how surfaces resist bacterial growth is crucial. The widely recognized ISO 22196 standard plays a critical role in this. By providing a standardized method for measuring antibacterial activity on plastics and other non-porous surfaces, it helps industries ensure product safety and performance. This standard evaluates the ability of treated surfaces to inhibit bacterial growth. This is particularly important for materials used in areas such as healthcare, food packaging, and consumer electronics, where microbial contamination can pose serious risks.

This standard applies to:

• Plastics and other non-porous surfaces treated with antibacterial agents
• Products whose surfaces come into frequent contact with human hands or food
• Environments requiring meticulous cleaning

However, this standard does not apply to textiles covered by ISO 20743, porous materials or products designed to release antibacterial substances into the environment.

The test method described includes:

• Sample preparation: The material sample is cleaned and sterilized.
• Bacterial inoculation: A known amount of bacteria (typically Staphylococcus aureus and Escherichia coli) is applied to the surface.
• Incubation: The sample is covered with a film and incubated for 24 hours at 35 degrees under high humidity.
• Measuring bacterial reduction: The number of viable bacteria is counted and compared to an untreated control surface.
• The result is expressed as a logarithmic reduction value: a logarithmic reduction of 2 means that 99 percent of the bacteria have died, while a logarithmic reduction of 3 means that 99,9 percent of the bacteria have died.

The ISO 22196 standard is considered important for the following reasons:

• Ensures product safety: By measuring antibacterial activity, manufacturers can verify that their products meet hygiene expectations, especially in regulated sectors.
• Aids marketing and compliance: Products with certified antibacterial performance under this standard can increase consumer confidence by making appropriate claims in advertising or labeling.
• Supports innovation: Companies can contribute to safer, cleaner technologies by testing and developing coatings or additives designed to inhibit microbial growth.

Our organization, which has been supporting businesses across all sectors for years through a wide range of testing, measurement, analysis, and evaluation activities, has a strong team of employees who closely follow global developments in science and technology and are constantly improving themselves. In this context, we also provide testing services in accordance with the ISO 22196 standard for "Measurement of Antibacterial Activity on Plastic and Other Non-Porous Surfaces."