3Rs

3Rs is a term used in several disciplines, most often to refer to two distinct frameworks: environmental sustainability and laboratory animal ethics. In environmental policy, the 3Rs stand for Reduce, Reuse, and Recycle. Reduce aims to minimize resource use and waste generation. Reuse emphasizes extending the life of products and components through multiple uses or repair. Recycle involves processing used materials into new products, closing material loops. The concept gained prominence in mid-20th century waste-management discussions and has become a staple of national and municipal recycling programs, product-design incentives, and corporate sustainability reporting. Critics point to uneven recycling rates and the energy and emissions associated with some recycling streams.

In laboratory science, the 3Rs refer to Replacement, Reduction, and Refinement, a framework for ethical use of animals in research proposed by Russell and Burch in 1959. Replacement seeks methods that avoid or replace animal use, such as in vitro assays, computer modeling, or non-sentient organisms. Reduction aims to minimize the number of animals used without compromising scientific integrity, often through robust experimental design and statistical planning. Refinement focuses on minimizing pain, suffering, and distress, improving housing and care, and selecting humane endpoints. Implementation typically involves institutional animal care and use committees and adherence to national or international guidelines, with ongoing evaluation of techniques and alternatives.

While both sets of 3Rs share the goal of reducing negative impacts, they apply to different domains: one to resource management and waste, the other to animal welfare in research. See also sustainability, waste management, animal welfare, humane experimental technique.