The 3Rs | an explainer
The 3Rs (Replacement, Reduction and Refinement) are a globally recognised set of guiding principles for the use of animals in science.
The 3Rs
A widely considered a keystone of research, testing and teaching involving animals and are intended to guide anyone planning to use animals for scientific purposes.
1
Replacement
Using non-animal methods wherever possible.
2
Reduction
Using the smallest number of animals possible.
3
Refinement
Improving procedures and care to minimise pain, suffering or distress experienced by animals.
The 3Rs in New Zealand
The 3Rs are well known within the New Zealand animal science and research community. However, they function primarily as guiding principles rather than enforceable legal requirements.
Referenced in Part 6 of the NZ animal welfare Act 1999:
which governs the use of animals for research, testing and teaching.
Promoted in the NAEAC good practice guide:
a key guidance document by the national animal ethics Advisory Committee (NAEAC), for individuals and organisations using animals for science.
Expected to be addressed in the code of ethical conduct:
held by organisations approved to use animals for research, testing, or teaching. This code sets out the rules and procedures that the organisation, its animal ethics committee, and any other organisations operating under that committee must follow.
Because there is no legal requirement to replace animals even where validated alternatives exist, the impact of the 3Rs ultimately depends on how terms such as “considered” and “promoted” are interpreted and applied in practice.
If you are unclear about the 3Rs, consider them as an internationally accepted framework guiding the use of animals in scientific contexts.
The 4th R – responsibility (or Respect)
The 3Rs were developed more than 60 years ago, in 1959. Their purpose was to reduce harm to animals, not to eliminate all harmful animal use.
Since then, scientific knowledge and society’s understanding of animal sentience have progressed considerably.
As a result, there is growing international discussion about adding a 4th R, most commonly described as responsibility or respect.
Both concepts emphasise moving beyond procedural harm reduction toward a stronger ethical culture in science.
Responsibility recognises a moral duty toward animals that goes beyond simply reducing harm in experiments.
Respect recognises animals as sentient beings with intrinsic value and calls for a culture of care, openness and ethical reflection in decisions involving their use.
These ideas are not currently embedded in New Zealand legislation, but they are increasingly discussed in international policy and research ethics.
In New Zealand, the national animal ethics advisory committee (NAEAC) has acknowledged the concept of a fourth R and continues to consider its relevance as part of ongoing ethical framework development.
The evolution from the 3Rs toward a possible 4th R demonstrates a broader shift from managing animal use to critically examining whether and how it should continue.
BAR’s position on the 3Rs
The 3Rs were designed to reduce harm, not eliminate the harmful use of animals altogether.
BAR supports strengthening the framework through a 4th R: Responsibility.
To us, responsibility means that when validated non-animal methods exist, they should be used. There is a clear and unimpeded responsibility to do so. Scientific progress obligates us to adopt better tools when they become available.
Within the existing 3Rs framework, replacement must be prioritised. Reduction and refinement may lessen harm, but only replacement removes it.
However, the current system in New Zealand is not structured to fully enforce replacement. Projects using animals may still be approved even where viable alternatives exist.
There are also pragmatic challenges. For example, Animal Ethics Committees do not have access to a comprehensive, centralised database of validated non-animal alternatives worldwide. Without clear visibility into available technologies, it can be difficult to ensure that every possible replacement method has been identified and considered.
This creates a gap between ethical principles and actual practice.
The 3Rs provide an important foundation, but foundations must be built upon.
By working together, we can ensure the next chapter of science is driven by innovation, responsibility and replacement.
Have questions about the 3Rs or animal research in New Zealand?
These topics can be complex, and understanding the accurate details matters. If you’d like an explanation of anything you’ve read here, we’re always happy to help unpack the science, ethics and policy.