After a long campaign, the BRC has succeeded in getting the requirement to quarantine returned goods for 48 hours removed. This was reduced earlier from 72 hours.

The note says:

Updated guidance: the guidance that items that have been returned, donated, or brought in for repair should be stored in a container or separate room for 48 hours or cleaned before display has been removed (section 5.5).

The updated guidance is at 

https://www.gov.uk/guidance/working-safely-during-coronavirus-covid-19/shops-and-branches