These are the 3Rs

The principle of the 3Rs was formulated by the researchers William Russell and Rex Burch in an article published in 1957. They argued that researchers should always strive to use as few animals as possible and to improve animal welfare during experiments. The starting point was the three Rs: Replace, Reduce and Refine.

Today, the 3Rs form an important basis of both Swedish and European legislation on the use of animals for scientific purposes. Everyone involved in animal experimentation is required to apply the 3Rs principle. An active application of the 3Rs contributes to increased research quality and improved animal welfare.

We have produced a short film that explains what the 3Rs are and the work of the 3Rs Center.

Replace

Replace refers to experiments that can replace live animals with other alternative methods that do not use live animals.

Animal experiments can only be replaced if there are animal free methods that give comparable information to the animal experiment.

Here are some examples of methods that have replaced animal experiments:

• computer modelling, mathematical modelling and AI
• artificial organs and tissues, such as organoids and 3D-models
• organ-on-chip
• cell cultures or organs ex vivo
• stem cells
• research on dead animals that have been euthanized for other purposes than to participate in an experiment
• research on models instead of real animals
• research on plants or micro organisms
• studies on synthetic or electronic material
• microdosing in humans.

Reduce

Reduce refers to experiments where the same knowledge and quality of data can be attained buy using fewer research animals than before. It can also mean that you get more information from the same animal than before without increasing the animal's suffering.

These are some examples of how to reduce the number of animals in research:

• to replace some components of the experimental procedure and thus reducing the number of animals being used even if you cannot replace the entire method or study
• to share data and results with other researchers, also negative data to reduce experiments
• to plan and design your experiments to avoid unnecessary use of animals
• to use organs and tissues from the same animal in several studies or share them with other researchers
• to use imaging methods to see what is happening inside an animal over time, which can give you more information from the same animal compared to other methods
• with good animal welfare and the right competence of those who work with the animals, one can reduce the number of animals being used in experiments.

Refine

Refine means that you make sure that your laboratory animals experience as little pain, suffering, discomfort and anxiety as possible, compared to previous comparable studies.

Refine also means that you can improve animal welfare and provide your laboratory animals with better life quality, for example by enriched material and larger spaces.

Here are some examples of refinement:

• to improve and refine pain relief and interventions with the animals
• to train the animals in approaching people, to be picked up and not to be stressed during various interventions
• to use materials that help the animals to play, hide and find security or improve the welfare in other ways so that the animals can perform their natural behaviours
• to make sure that the animals are as short time as possible in experiments and avoid to use the animals’ death as an end point.

Regulations

• EU Directive 2010/63/EU on protection of animals used for scientific purposes (ec.europa.eu)

• Guidance documents to implement the EU Directive 2010/63/EU on protection of animals used for scientific purposes (ec.europa.eu)