The five dimensions
Safe people — only accredited, trained researchers get access. Safe projects — each use is approved for a specific public-benefit purpose. Safe settings — analysis happens in a controlled environment that prevents data removal. Safe data — data is de-identified proportionate to the setting. Safe outputs — results are checked before release so no individual can be re-identified.
Why it defines what a TRE is
Originating with the UK Office for National Statistics, the Five Safes is the yardstick regulators and data custodians use to evaluate research platforms. A platform that lets approved users download record-level data fails “safe settings” and “safe outputs” regardless of its marketing. A Trusted Research Environment is, by definition, an environment engineered so all five safes hold — with an auditable airlock controlling everything that leaves.