What does this mean in practice?
As a licence holder you should do everything reasonable to maintain the 3Rs in your research work with animals. This includes the replacement of animals by using alternatives, reduction of animal numbers (while maintaining an appropriate number to validate your research), and the refinement of experimental procedures and husbandry of all animals under your care.
Of all the Rs, you have the greatest influence on refining procedural techniques and animal husbandry.
How do I comply with PIL Standard Condition 1?
Like all standard conditions, you are expected to continually meet this responsibility. It is not enough to rely solely on the 3Rs section outlined in the Project Licence under which you are working.
The application of the 3Rs is an ongoing and evolving process. In research, new discoveries and technologies emerge rapidly, including potential replacements or more refined animal models. Staying informed about these developments, and carefully planning any changes to avoid introducing confounding factors into your data, is a vital part of managing animal studies and complying with your licence conditions.
While it is usually straightforward to describe refinements you have already implemented, consider this question: if an ASRU inspector asked, “How do you ensure you are using current replacement technologies?”, how would you respond?
What resources are available to support me?
A wide range of support is available to help you meet your responsibilities and embed the 3Rs in your work.
Local and Establishment Support
- Research colleagues and collaborators – Your peers are often the first source of advice, shared experience, and good practice.
- AWERB (Animal Welfare and Ethical Review Body) – AWERB provides oversight, guidance, and standards relating to animal care, welfare, and ethical use within your establishment. These standards help drive continual improvement in animal welfare and the application of the 3Rs.
Animal Facility and Named Roles
Members of the animal facility team can provide practical advice and support on implementing the 3Rs, including:
- NACWOs – Named Animal Care and Welfare Officers
- NTCO – Named Training and Competency Officer
- NIO – Named Information Officer
- NVS – Named Veterinary Surgeon or veterinary support
- Animal Care Technicians, who have day‑to‑day expertise in animal care, husbandry, and welfare
External Organisations and Research Bodies
Several national and international organisations offer guidance, training materials, and best‑practice resources:
- NC3Rs – Provides extensive 3Rs resources specifically designed to support researchers working with animals.
- NORECOPA – Norway’s 3Rs platform, offering a wide range of tools and resources relevant internationally.
- LASA & FELASA – The Laboratory Animal Science Association and the Federation of European Laboratory Animal Science Associations support collaboration and the sharing of best practice across the wider scientific community.
- UFAW (Universities Federation for Animal Welfare) – Offers tools, guidance, and authoritative publications that are a valuable addition to any researcher’s library.
- RSPCA – Works closely with AWERBs, researchers, and animal technicians and provides resources addressing laboratory animal welfare and ethical considerations.
Animal Suppliers
Animal suppliers often provide more than animal sourcing and transport. Many now offer educational materials, technical advice, and 3Rs‑related resources at little or no cost.
Recommended suppliers include:
What happens if I don’t comply with PIL Standard Condition 1?
This condition is most commonly breached as part of a wider non‑compliance with other licence conditions. Failing to meet any of the other 21 standard conditions means your work is unlikely to be conducted in the most refined way or using the minimum number of animals necessary.
Non‑compliance often results in animals having experienced, or being at risk of experiencing, increased pain, suffering, distress, or harm for longer than anticipated. This can also lead to the need to use additional animals to obtain sufficient robust data to validate the study.
Where this condition is not met, the usual outcome is locally delivered retraining within the establishment. In some cases, individuals holding a Personal Licence (PIL) may also be required to produce a written report explaining how they intend to meet and maintain their licence conditions going forward.
How does ASRU assess compliance with PIL Standard Condition 1?
ASRU assesses compliance with PIL Standard Condition 1 by reviewing how Personal Licence holders apply the principles of replacement, reduction, and refinement in practice.
During an inspection, ASRU may review evidence of discussions with the Project Licence Holder about humane endpoints and welfare controls. Inspectors may also speak directly with the PIL holder to confirm their understanding of 3Rs responsibilities and awareness of current 3Rs challenges or initiatives.
Compliance may be further assessed through observation of animal care and regulated procedures to ensure they are conducted in line with the 3Rs.
How do I know if I am complying with PIL Standard Condition 1?
As a new Personal Licence (PIL) holder, you will be supported by local systems designed to help identify and prevent potential non‑compliance.
Many establishments use study plans or experimental plans. These are simplified, practical versions of the project licence protocol and describe exactly what you will do to the animals, including group sizes and key procedures. Preparing these plans provides an opportunity for review by the NACWO or NVS, who can check that your work aligns with the project licence and advise on welfare considerations. They may recommend refinements such as the use of analgesia or, where authorised, anaesthesia to reduce pain or distress.
Although project licences set an overall limit on animal numbers, you should continually aim to refine and reduce animal use within your own studies. Using experimental design tools, such as the NC3Rs Experimental Design Assistant (EDA), can help you do this. These tools allow you to:
- Create a clear, step‑by‑step visual plan of your experiment that can be attached to your study/experimental plan
- Receive feedback on your design and improve it as the study develops
- Incorporate randomisation, blinding, and sample‑size calculations to ensure appropriate and efficient animal use
The EDA is free to use and allows you to save and share designs with colleagues, helping you build good practice over time.
You may also work in an establishment with a tissue‑sharing policy, enabling the use of surplus tissues from breeding programmes (for example, animals with an unsuitable genotype), further supporting reduction where appropriate.