Key summary pointers
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- ISO 21702 Is an international testing method for measuring antiviral activity on plastics and other non‑porous surfaces that have been treated with antiviral agents.
- ISO 21702 virucidal efficacy testing method helps in evaluating how effectively a treated surface reduces the infectivity of viruses compared with an untreated control surface.
- Typical applications include medical devices, consumer products, packaging and electronics.
- The test is commonly used to validate antiviral plastics, coatings and treated surfaces
- It supports product validation and antiviral performance claims for plastics and non-porous materials.
Summary
ISO 21702 is a standardized test method used worldwide for testing whether plastics and non-porous materials are able to reduce the infectivity of a virus compared to untreated materials. In the test, a test material is challenged with viral suspension and incubated under control conditions, after which the reduction of the virus titre is measured and compared with a control sample.
What is ISO 21702?
ISO 21702 virucidal efficacy testing is an international standard developed by the International Organisation of Standardization(ISO) to evaluate antiviral activity on non-porous materials, particularly plastics.
This standard offers a step-by-step approach to testing antiviral activity of treated antiviral samples in a laboratory under controlled conditions.
The standard establishes requirements for:
- Preparation of virus suspensions
- Selection and cultivation of host cells
- Application of virus inoculum on material surfaces
- Incubation under controlled environmental conditions
- Recovery and quantification of infectious virus particles
Materials That Can Be Tested Under ISO 21702
ISO 21702 primarily applies to plastics and other non-porous materials.
Examples of materials suitable for testing include:
- Polymer-based plastics
- Antiviral coated surfaces
- Plastic films and laminates
- Consumer electronics casings
- Medical equipment housings
- Plastic packaging materials
- Interior architectural surfaces
Test Viruses Used in ISO 21702
Commonly used viruses in ISO 21702 virucidal efficacy testing include:
- Influenza A virus (H3N2)
- Feline calicivirus
Overview of the ISO 21702 Test Method
The ISO 21702 virucidal efficacy testing follows a set of controlled laboratory procedures to assess the antiviral performance.
Preparation of Test Specimens
Test specimen and untreated control specimens are prepared according to standardized dimensions and sterilized before testing.
Virus Inoculation
A specific amount of virus suspension is inoculated onto the surface of the specimens.The inoculated droplet is covered with a thin film to maintain uniform contact between the virus and the surface.
Incubation Conditions
Samples are incubated under controlled environmental conditions, typically:
- Temperature: 25°C
- Relative humidity: ≥ 90%
- Incubation time: 24 hours
These conditions allow sufficient interaction between the virus and the tested material.
Virus Recovery
After incubation, the virus is recovered from the surface using neutralizing media.
Viral Quantification
Recovered virus samples are analyzed using infectivity assays to determine the remaining viral concentration.
Control used in ISO 21702
Controls are essential to ensure the accuracy and reliability of ISO 21702 virucidal efficacy testing results.
The standard requires the use of untreated control materials that are identical to the test samples but do not contain antiviral agents.
These controls help determine:
- The natural survival of viruses on untreated surfaces
- Baseline viral infectivity levels
- The actual antiviral performance of treated materials
This section describes the various controls used for the ISO 21702 test alongside the sample.
1. Cytotoxicity control
The ISO 21702 test is used to assess cytotoxicity to cells cultured in liquid medium under controlled laboratory conditions. This control does not try to assess the real-world scenario of toxicity. Cytotoxicity control is setup to ensure that observed virus reduction is due to antiviral efficacy, not because cells were killed by the test samples. This helps to avoid false interpretation of test results.
2. Untreated Sample control
In many cases, it has been found that many plastics and non-porous substances possess inert antiviral activity against viruses. The inert antiviral activity of the sample surface and the compound that is coated over it should be differentiated.
This is achieved by contaminating the untreated surface with a virus for same period of time as that of the test sample. Post-incubation the collected virus is then used to assess the antiviral activity of the untreated sample surface. This is a critical control to assess the true antiviral potential of the compound coated on the surface.
3. Titration control
If the concentration of the virus is too less, it will symbolize a problem with the virus stock. The virus is directly taken from the stock and mixed with the host cells to find out the initial concentration of the virus in the experiment.
This is an important check if there was an excellent infectivity titer of the virus used to conduct the sample test.
Furthermore, it can give us information regarding the highest concentration of the virus which can be extracted from the testing.
How Antiviral Activity Is Calculated?
In ISO 21702, antiviral performance is expressed using the R value.
The R-value refers to the decrease in the concentration of the virus on the sample corresponding to a control sample. It is calculated as the difference between the amount of virus remaining on the reference and the test sample (both of which are expressed as base 10 logarithms).
For the antiviral activity to be established, the sample tested must obtain an R-value of 2 or more.
|
R-Value |
Interpretation |
|
R=1 |
90% reduction of infectious virus compared to control sample |
|
R=2 |
99% reduction of infectious virus compared to control sample |
|
R=3 |
99.9% reduction of infectious virus compared to control sample |
Viruses degrade and become inactive on any surface over time. This makes it essential for the R-value to be measured correspondingly based on the inert control.
The R-value gives information on virus inactivation on treated samples.
Industries That Use ISO 21702 Testing
Many industries rely on ISO 21702 testing to validate antiviral materials.
Healthcare and Medical Devices
Hospitals use antiviral materials to reduce contamination on equipment and surfaces.
Consumer Electronics
Manufacturers test antiviral coatings for devices such as smartphones, keyboards and touch screens.
Packaging Industry
Antiviral packaging materials help reduce contamination risks in food and pharmaceutical packaging.
Construction and Interior Materials
Antiviral coatings are used in wall panels, laminates and other interior surfaces.
Public Infrastructures
Public transport systems, elevators and shared equipment increasingly incorporate antiviral materials to improve hygiene standards.
ISO 21702 virucidal efficacy testing helps these industries demonstrate measurable antiviral performance.
When Should Manufacturers Consider ISO 21702 Testing?
Manufacturers should consider ISO 21702 testing when developing or marketing products that claim antiviral performance.
Testing becomes especially important when:
- Launching materials with antiviral additives or coatings
- Entering regulated markets requiring validated claims
- Developing products for healthcare or hygiene-sensitive environments
- Differentiating products in competitive markets
- Demonstrating science-backed product performance
Conducting ISO 21702 virucidal efficacy testing early in product development can also help manufacturers optimize formulations and select effective antiviral technologies.
Difference Between ISO 21702 and ISO 22196
ISO 21702 is often compared with ISO 22196, another widely used antimicrobial testing standard.
However, the two standards measure different types of microbial activity.
ISO 22196 determines bacterial reduction on plastic surfaces, whereas ISO 21702 focuses specifically on the reduction of viral infectivity.
Manufacturers developing antimicrobial materials often perform both tests to demonstrate broad-spectrum protection.
Why MIS is a trusted partner for ISO 21702 testing
MIS offers:
- Testing as per standard guidelines
- Controlled laboratory environments for viral assays
- Expert virology and microbiology teams
- Reliable and reproducible testing results
- Scientific support for product validation and regulatory documentation
By working with a trusted testing partner, manufacturers can ensure their antiviral claims are supported by credible scientific evidence.
FAQ Section
1. What exactly does ISO 21702 measure?
ISO 21702 test measures the antiviral activity of treated plastics and other non-porous materials. This test measures the extent to which a treated surface can reduce infectivity of the virus compared to the untreated surface after a specified contact time.
2. Can any surface be tested with ISO 21702?
No, ISO 21702 is specifically designed for plastics and other non-porous materials.
3. What does “log reduction” mean in antiviral test results?
The term “log reduction”refers to the effectiveness of an antiviral treatment in reducing the number of viruses present on the surface. Log reduction is measured on base-10 logarithmic scale.
4. Can ISO 21702 results be used for antiviral marketing claims?
Yes, the results of ISO 21702 testing can be used to demonstrate antiviral activity and marketing claims. However, it is imperative to ensure that your claims are in line with ISO 21702 test requirements and passing criteria. Added to this, regulatory requirements may vary across the region so marketing claims should also comply with regional regulatory requirements.
5. Does passing ISO 21702 mean a surface prevents infections?
Passing ISO 21702 test means that the test surface is able to match passing criteria stipulated as per EN 21702 test guideline. Under EN 2102 test conditions, the surface has the ability to reduce viruses over time. Although ISO 21702 testing results support antiviral effectiveness, it does not guarantee the prevention of infectious viruses in the real-world environment.
6. Does a higher log reduction always mean better antiviral performance?
Yes, a higher log reduction generally indicates greater antiviral effectiveness, as it reflects a larger decrease in the number of infectious viral particles on the tested surface.
7. Is ISO 21702 the same as antiviral testing for textiles?
No, ISO 18184 is used to check antiviral performance of textiles whereas ISO 21702 is applicable to antiviral plastic and non-porous surfaces.