“Detriment” is a legal term. It means unfair action by an Employer against an Employee during employment which falls short of an actual dismissal. In Ministry of Defence v Jeremiah  the Court of Appeal considered the meaning of detriment in the context of discrimination. Brightman LJ said; “ I think a detriment exists if a reasonable worker would or might take the view that the duty was in all the circumstances to his detriment”. Lord Justice Brandon said; “I do not regard the expression ‘subjecting… to any other detriment’ as meaning anything more than ‘putting under a disadvantage”.: You can make an employment tribunal claim if you are subjected to a detriment at work because you reasonably believed that being at work would place you (or someone else, such as a household member) in serious, imminent danger.
This right is found in s44 of the Employment Rights Act 1996 and only applied to employees until now. The Employment Rights Act 1996 (Protection from Detriment in Health and Safety Cases) (Amendment) Order 2021 extend protection for health & safety detriments to all workers (not just employees).
This has come about due to the Supreme Court’s decision in R (on the application of the IGWU) v Secretary of State for Work and Pensions, where it was held that confining such protection to employees was a breach of the EU Health & Safety Framework Directive. The extension to workers applies to any detriments taking place on or after 31 May 2021.