Section 111 of the Water Industry Act 1991 makes it illegal to discharge fat, oil or grease into the public sewer.
There is no grey area, no minimum volume and no exception for small businesses.
If your kitchen is pouring used cooking oil down the drain - it's breaking the law.
The consequences are real and increasing. Environmental Health officers across the UK are actively targeting food businesses for improper oil disposal.
The Food Safety Act 1990 requires all food premises to prevent drainage issues that could affect hygiene standards. An improvement notice can be issued on the spot and a prohibition order can close your kitchen immediately.