On April 25, 2025, a proficiency testing exercise will be conducted to evaluate laboratories’ capabilities in applying the EN 1276:2020 standard, accredited under ISO/IEC 17043. This exercise aims to assess whether participating laboratories are competent in analyzing the bactericidal efficacy of chemical disinfectants in food, industrial, domestic, and institutional settings, using Pseudomonas aeruginosa as the reference organism. Interlaboratory comparisons are essential to ensure the quality and precision of procedures in non-medical sectors.
What Is Proficiency Testing Under EN 1276?
EN 1276:2020 specifies a quantitative suspension test method for evaluating the bactericidal activity of chemical disinfectants. This standard is widely used to certify disinfectant products in the food, industrial, domestic, and institutional sectors. While it excludes medical applications and products for use on living tissues, it does allow application for hand hygiene within the specified sectors.
The primary purpose of EN 1276:2020 is to ensure that disinfectants used in critical environments are effective against specific microorganisms, achieving a significant reduction in bacterial load. The standard includes organisms such as Pseudomonas aeruginosa (ATCC 15442), Escherichia coli (ATCC 10536), Staphylococcus aureus (ATCC 6538), and Enterococcus hirae (ATCC 10541). These organisms represent diverse microbiological challenges, simulating real-world conditions. All of them are scheduled for testing in our proficiency testing programs over the next five years. For details about our five-year agenda, feel free to inquire.
A critical feature of EN 1276:2020 is its focus on the logarithmic reduction of bacteria. For a disinfectant to meet the standard’s requirements, it must demonstrate a minimum 5-log reduction in colony-forming units (CFU). This corresponds to eliminating 99.999% of bacteria, a necessary efficacy level to prevent infections and ensure optimal hygiene conditions.
Pseudomonas aeruginosa as a Test Organism
Pseudomonas aeruginosa is a Gram-negative bacterium known for its ability to survive under diverse environmental conditions and its intrinsic resistance to multiple antimicrobial agents. These characteristics make it an ideal model for disinfectant testing, presenting a significant challenge in terms of efficacy.
In tests conducted under EN 1276:2020, the standard strain ATCC 15442 of Pseudomonas aeruginosa is used. This strain is selected for its relevance in food and industrial settings, where bacterial contamination can compromise both safety and product quality. Using this strain ensures that evaluated disinfectant products meet the highest efficacy standards, even against highly resistant bacteria.
Testing Conditions
EN 1276:2020 outlines stringent testing conditions designed to mimic real-world application scenarios. These include two primary conditions:
- Clean conditions: A solution of 0.3 g/L bovine albumin is used as an interfering substance. This simulates environments with minimal organic matter, such as pre-cleaned surfaces or low-risk contamination areas.
- Dirty conditions: The concentration of bovine albumin increases to 3 g/L to reflect environments where organic matter may be present, such as food-contact surfaces, industrial equipment, or high-traffic areas.
Additionally, the standard allows for temperature ranges between 4°C and 60°C and contact times from 1 to 60 minutes, depending on the product and intended use. This flexibility enables the evaluation of a broad spectrum of disinfectants.
Testing Methods
The preferred method for assessing bactericidal activity under EN 1276:2020 is dilution-neutralization. This method halts the disinfectant’s activity after the specified contact time, ensuring that only its effectiveness during that period is evaluated. This approach is vital to maintaining the accuracy and comparability of results across different products.
When neutralization is not feasible due to the disinfectant’s chemical properties, the membrane filtration method may be used. This involves capturing surviving bacteria on a membrane for subsequent enumeration.
Both methods require prior validation to ensure they do not interfere with the microorganisms’ viability or the product’s efficacy. Validation includes rigorous controls to verify that experimental conditions do not introduce lethal effects and that the neutralizers are appropriate for the disinfectant in question. This ensures that results are reproducible and reliable, meeting international quality standards.
Efficacy Requirements
To comply with EN 1276:2020, a general-purpose disinfectant must demonstrate at least a 5-log reduction in bacterial count under the specified testing conditions. This level of efficacy is critical for applications in sectors like food processing, where the presence of Pseudomonas aeruginosa can compromise both product quality and consumer safety.
Participate in Our Proficiency Testing
The proficiency testing exercise in April 2025 will follow EN 1276:2020 guidelines to assess laboratories’ technical abilities in applying methods to analyze disinfectants against Pseudomonas aeruginosa. Participating laboratories will prepare a bacterial suspension of the ATCC 15442 strain, which will be exposed to the disinfectant under controlled conditions. Variables such as contact time and temperature will be adjusted as specified by the standard.
This proficiency test serves several key purposes to ensure the quality and technical competence of participating laboratories:
- Accreditation compliance: The test helps laboratories meet requirements set by ISO/IEC 17025, which mandates regular participation in proficiency testing programs to ensure technical competence within the scope of accreditation.
- Identification of technical issues: Laboratories can identify potential deficiencies in their testing methods and implement corrective actions to improve the accuracy and reliability of their results.
- Increased client confidence: Participating laboratories will receive a certificate attesting to their technical competence, strengthening client trust in their services.
The disinfectant product, supplied by SHAPYPRO, will be accompanied by a detailed protocol outlining specific test conditions, including contact time, temperature, and simulated scenarios (clean or dirty conditions). This protocol ensures standardized testing conditions that reflect practical use cases for disinfectants.
Biocidal Active
The proficiency test consists of two main stages:
- Determination of effective concentration: Participating laboratories will calculate the minimum concentration of disinfectant required to achieve the standard’s 5-log reduction in Pseudomonas aeruginosa counts.
- Reduction rate assessment: Once the effective concentration is determined, laboratories will evaluate the reduction rate achieved by the disinfectant under the prescribed conditions, accounting for variables like contact time and temperature.
This proficiency test is tailored for laboratories that meet one or more of the following profiles:
- Laboratories accredited under ISO/IEC 17025.
- Laboratories in the process of accreditation, seeking to enhance their technical competence in disinfectant evaluation.
- Laboratories interested in continuously monitoring their performance to ensure consistency and quality in their results.
SHAPYPRO will ensure that the organization and processing of results comply with international standards such as ISO/IEC 17043, ISO 5725, and ISO/IEC Guide 35, guaranteeing valid and comparable results among participating laboratories.
For more information about this proficiency test or participation requirements, contact us at SHAPYPRO.
Why Choose SHAPYPRO’s Proficiency Testing?
With over 10 years of experience in evaluating the efficacy of disinfectant products, we offer proficiency testing programs that comply with the requirements of ISO/IEC 17043 and conform to EN 14885:2022/AC:2023..
We are the only accredited provider worldwide in this field of testing under ISO/IEC 17043. [Click here to download the accreditation]
Our extensive knowledge allows us to assist clients in developing new methods and R&D projects. We have previously developed proficiency testing programs under EN 1276.
Additionally, we are manufacturers of soft diluted soap necessary for both developments.
We provide customized proficiency tests. All tests are conducted in accordance with internationally validated standards and guidelines.
Interested in our 5-year schedule? Contact us!