EN 1657 is a key reference standard for evaluating the fungicidal and yeasticidal activity of chemical disinfectants. Microbiological safety is a cornerstone in both the veterinary and chemical fields. Ensuring that disinfectants and antiseptics meet defined efficacy criteria under controlled conditions is essential to protect animal health, secure biosecurity in facilities, and comply with the European regulatory framework.
In this context, EN 1657 serves as a key reference standard. Developed under CEN/TC 216 – Chemical Disinfectants and Antiseptics, it sets out a quantitative suspension test method to determine the fungicidal and yeasticidal activity of biocidal products used in the veterinary area.
This article explains the scope of EN 1657, its methodology, the updates introduced in the 2024 draft revision, its relationship with other standards, and its impact on the industry.
Scope Of EN 1657
The EN 1657 standard is specifically designed to assess the efficacy of chemical disinfectants and antiseptics in the veterinary field. Its applications include:
- Facilities for animal breeding and husbandry.
- Transport and disposal of animals.
- Veterinary production areas.
- Veterinary care facilities.
- Products for teat disinfection in dairy animals.
The legal framework of reference is Regulation (EU) No 528/2012 concerning the making available on the market and use of biocidal products, which governs the authorization and use of such products in the European Union.
Purpose Of EN 1657
The standard establishes a quantitative suspension method to verify that a disinfectant or antiseptic demonstrates sufficient activity against fungi and yeasts under specific laboratory conditions simulating practical use.
The reference organisms used in testing are:
- Candida albicans (yeast).
- Aspergillus brasiliensis (formerly Aspergillus niger) as a representative mold.
These organisms ensure that the tested product demonstrates efficacy against the main types of fungal contamination that may occur in veterinary environments.
Methodology Of The Suspension Test
The EN 1657 test follows a precise protocol to guarantee comparable and reproducible results across laboratories:
- Preparation of microbial suspension: standardized suspensions of Candida albicans or Aspergillus brasiliensis.
- Exposure to disinfectant: suspensions are exposed to the product under defined time, temperature, and concentration.
- Addition of interfering substances: elements simulating dirt or organic matter (e.g., milk in teat disinfectants).
- Neutralization: use of an agent to stop the disinfectant’s action at the precise moment.
- Recovery methods:
- Dilution-neutralization.
- Membrane filtration, depending on the product and microorganism.
- Survivor count: quantification of viable fungal and yeast cells.
- Logarithmic reduction calculation: expressed as log10 reduction in microbial numbers.
Efficacy Requirements Of EN 1657
For a disinfectant to be deemed effective under EN 1657, it must achieve a minimum reduction of 4 log in viable organisms under defined test conditions.
In practical terms, this means the product must eliminate at least 99.99% of fungi or yeasts present in the suspension.
This aligns with the general framework of EN 14885, which defines the relationship between European disinfectant standards and their application areas.
Updates In The 2024 Revision
The draft FprEN 1657:2024 introduces several changes compared to the previous version (EN 1657:2016), aimed at improving clarity and harmonization:
- Clarification of ambiguities: refined definitions and conditions to avoid divergent interpretations across laboratories.
- Alignment with other CEN/TC 216 standards: harmonization with EN 1656 (bactericidal activity in veterinary areas) and other suspension test methods.
- Adjustments in interfering substances: specifying milk for teat disinfectant testing to better simulate real-use conditions.
- Methodological flexibility: fewer unnecessary restrictions, enhancing reproducibility without compromising robustness.
- Improved readability: simplified language and better organization of technical sections.
These updates reflect the effort to adapt the standard to current practice and the needs of both laboratories and the chemical/veterinary industry.
Impact Of EN 1657 On The Chemical And Veterinary Sectors
The implementation of EN 1657 has direct implications for safety and quality in the chemical sector and veterinary activities:
- Market confidence: manufacturers can demonstrate product efficacy with standardized scientific data.
- Animal health protection: ensures that disinfectants used in breeding, transport, and veterinary care are truly effective against fungi and yeasts.
- Regulatory compliance: facilitates biocide authorization under Regulation (EU) 528/2012.
- International standardization: alignment with EN 14885 contributes to harmonized regulation within the EU and with international bodies.
Relationship Between EN 1657 And Other European Standards
EN 1657 forms part of an interconnected regulatory framework:
- 1- EN 14885: framework standard linking disinfectant tests to application areas (healthcare, veterinary, domestic, industrial).
- 2- EN 1656: quantitative suspension test for bactericidal activity in veterinary areas, complementing EN 1657.
- 3- EN 13697: surface test methods evaluating efficacy under more practical conditions.
This system ensures that biocidal products can be assessed comprehensively across different usage contexts.
The Role Of SHAPYPRO In Applying EN 1657
At SHAPYPRO, we specialize in designing and managing international proficiency testing (PT) programs under standards such as EN 1657. Our mission is to help laboratories validate their methods by offering interlaboratory comparisons that strengthen result reliability.
By participating in SHAPYPRO’s PT programs, laboratories can:
- Benchmark their performance against other institutions.
- Detect deviations in results.
- Demonstrate technical competence according to ISO/IEC 17043.
This ensures that EN 1657 is not only a regulatory requirement, but also an opportunity for continuous improvement and excellence in the chemical and veterinary sectors.
Conclusions
The EN 1657 standard is essential for assessing the fungicidal and yeasticidal activity of disinfectants and antiseptics in veterinary environments. Its 2024 revision strengthens methodological clarity, harmonization with other standards, and real-use applicability.
For manufacturers, it provides a clear path to demonstrate product efficacy. For laboratories, it establishes a robust framework for method validation. And for the market, it guarantees that safety and quality remain non-negotiable priorities.
Within the framework of Regulation (EU) 528/2012, EN 1657 consolidates its role as a strategic tool to ensure biosecurity, competitiveness, and trust in biocidal products.
At SHAPYPRO, we closely monitor these regulatory updates, supporting laboratories through technical expertise and interlaboratory comparison programs. Learn more in our article on the comparison of suspension tests for disinfectants or visit the CEN-CENELEC website to access official documentation.