Quick insights
- EN 17422 is a phase 2 step 2 test method evaluate the bactericidal activity of teat disinfectants used in veterinary areas
- It simulates real-world conditions using synthetic skin, helping manufacturers support efficacy claims for animal-care environments
- This test method is applicable to pre and post-milking teat disinfectants used in breeding, husbandry, transport in veterinary areas
- Under EN 17422, pre-milking disinfectants must achieve a minimum of 3 log reduction and post-milking disinfectants must achieve a minimum 4 log reduction
Summary
EN 17422 is a quantitative carrier based European standard used to assess the bactericidal efficacy of Pre and post- milking teat disinfectants. The test is specifically designed for disinfectants intended for application on teat skin without mechanical action. The method simulates realistic hygiene conditions within a controlled laboratory setting. EN 17422 helps demonstrate that teat disinfectants meet required performance criteria to support mastitis prevention claims required under EU veterinary hygiene and biocidal product frameworks.
Also read – EN 17422 vs EN 1276: Which European Disinfectant Test Applies to Your Product?
What is EN 17422?
EN 17422 is a quantitative carrier based ( phase 2 step 2) test method used to evaluate the bactericidal efficacy of pre/post milking teat disinfectants applied on the teat skin without mechanical action.
Where is this standard applicable?
EN 17422 is designed for pre and post-milking teat disinfectants used in
- Breeding
- Husbandry
- Production
- Transport
- Veterinary care
- Disposal of animals (excluding food chain processing)
Why bactericidal testing matters in veterinary environments
In veterinary environments, risk of pathogen transmission through contact is very common among animals. Microbial contamination control helps eliminate the transmission and maintain hygiene conditions in the veterinary care environments.
Bacterial contamination risks in veterinary environments
- High transmission risk in animal housing – Veterinary environments often involve close animal contact, creating favourable conditions for bacterial spread.
- Contaminated surfaces may spread infections – Pathogenic bacteria can survive on contaminated surfaces for extended periods. Inadequate disinfection may contribute to disease transmission between animals, workers and equipment.
- Biosecurity is critical in livestock operations – Strong hygiene and disinfection protocols are essential for maintaining biosecurity in livestock and poultry operations.
Therefore, it is important to ensure efficacy of disinfectants designed for veterinary environments. EN 17422 test method helps manufacturers support bactericidal efficacy claims for veterinary disinfectant products. Testing under simulated practical conditions, this method provides stronger evidence of real-world performance with validated efficacy data. This improves confidence among veterinarians, farm operators and regulatory bodies when selecting disinfectant solutions.
What does EN 17422 evaluate?
- Bactericidal efficacy under practical conditions – The standard evaluates how effectively a disinfectant reduces bacterial contamination under realistic conditions. The method quantifies bacterial reduction after disinfectant exposure for a defined contact time. This reflects intended practical use conditions.
- Assesses Performance After Defined Contact Time – Disinfectants are evaluated based on their activity within specific exposure times relevant to real-world use.
- Evaluates disinfectant action on surfaces – EN 17422 test method uses non-porous carriers to simulate practical environmental surfaces.
How does EN 17422 testing work?
- Inoculation– Bacterial suspension with interfering substance is inoculated onto a synthetic skin test surface and kept at 30°C for a defined period of conditioning.
- Disinfectant exposure – Inoculated test surface is then immersed in the disinfectant samples/dilutions of the product for a defined contact time.
- Neutralization and recovery – At the end of contact time, test surface is transferred into the neutralizer. The bacteria are removed using ultrasound technique and recovered bacteria are enumerated by plate count method.
- Result interpretation – The number of surviving bacteria from the treated surface are compared with number of bacteria recovered in control test.
- Passing criteria – To pass the test, Pre-milking disinfectants require ≥ 3 log reduction and post-milking disinfectants require ≥ 4 log reduction.
Clean vs dirty conditions
EN 17422 test method uses both clean conditions and dirty conditions to test the bactericidal efficacy of disinfectants. Dirty conditions involve addition of interfering substances that replicate organic contamination in real-world use.
Pre-milking teat disinfectants are evaluated under clean conditions, focusing on rapid bacterial reduction to minimize contamination risk prior to milk collection. In contrast, post-milking teat disinfectants are tested under dirty conditions, simulating exposure to milk residues and organic matter. By incorporating these differentiated conditions, EN 17422 provides accurate efficacy data that reflects real-world application, meeting EU regulatory requirements.
Key factors influencing EN 17422 results
Several factors influence the results, including:
- Contact time
- Product concentration
- Organic soiling
- Test surface type
- Temperature and other test conditions
EN 17422 vs EN 14349 vs EN 1656
| Parameter | EN 17422 | EN 1656 | EN 14349 |
| Test type | Quantitative carrier test (Phase 2 step 2) | Quantitative suspension test (Phase 2, step 1) | Quantitative carrier test (Phase 2 step 2) |
| Application area | Pre and post-milking teat disinfectants (husbandry, production, transport etc) | Veterinary disinfectants (Animal housing, farms, transport) | Veterinary disinfectants (Surface applications) |
| Mandatory test organisms | Escherichia coli (ATCC 8739) and Staphylococcus aureus (ATCC 6538P) | General veterinary disinfectants: Enterococcus hirae, Proteus hauseri, Pseudomonas aeruginosa, Staphylococcus aureus Teat disinfectants: Escherichia coli, Staphylococcus aureus, Streptococcus uberis | Enterococcus hirae, Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, MRSA, Salmonella enterica, Candida albicans |
| Passing criteria | Post-milking – ≥ 4 log reduction Pre-milking – ≥ 3 log reduction | ≥ 5 log reduction | ≥ 5 log reduction |
Read more –
Common bacteria relevant in veterinary disinfectant testing
EN 17422 typically uses Escherichia coli (ATCC 8739) and Staphylococcus aureus (ATCC 6538P) as mandatory test organisms for veterinary disinfectant testing. Other relevant bacterial strains include Enterococcus hirae, Pseudomonas aeruginosa, Streptococcus uberis etc.
Common reasons for EN 17422 failure
Products may fail EN 17422 test method for several reasons, they include:
- Insufficient active ingredient concentration
- Poor efficacy under dirty conditions
- Inadequate contact time
- Instability during practical application
- Reduced performance against specific bacterial strains
- Incomplete or ineffective neutralization
How to select a laboratory for EN 17422 testing
For testing in accordance with EN 17422, choose a lab with:
- Experience in veterinary bactericidal testing
- Availability of relevant bacterial strains
- Compliance with European standards
Need help with EN 17422 testing?
Selecting the right testing strategy is essential for evaluating disinfectant efficacy in veterinary applications. At MIS, our expert microbiology team performs EN 17422 testing in compliance with international guidelines and are available to provide assistance throughout the process, right from choosing the most appropriate test strategy to generating reliable and reproducible results. To discuss your testing needs, contact our experts today.
To get a quote on EN 17422 testing, contact our experts now.
FAQs
1. What is EN 17422 used for?
EN 17422 is used to evaluate the bactericidal efficacy of pre/post milking teat veterinary disinfectants on surfaces under practical conditions.
2. Is EN 17422 a suspension test?
No, it is a carrier based surface test designed to simulate practical disinfection conditions.
3. What factors can affect EN 17422 test outcomes?
Contact time, organic load, temperature, product concentration and surface conditions are some of the factors that influence EN 17422 outcomes.
4. What is the difference between EN 17422 and EN 14675?
EN 17422 evaluates bactericidal efficacy on contaminated surfaces while EN 14675 primarily evaluates virucidal activity for veterinary disinfectants
5. Is EN 17422 used for veterinary antiviral disinfectants?
No, the standard is primarily designed to evaluate bactericidal efficacy of veterinary disinfectants
6. Why are dirty conditions important in EN 17422 testing?
Dirty conditions simulate realistic veterinary contamination scenarios where organic matter may interfere with disinfectant performance.
7. Which veterinary environments commonly require EN 17422?
Pre/post-milking veterinary disinfectants used in breeding, husbandry, production, transport, veterinary care etc commonly require EN 17422 test method.
