Approved Document H From the Building Regulations 2000, (amended 2002), advises that the requirement for an adequate drainage system should minimise the risk of blockage or leakage.
Drainage serving kitchens in commercial hot food premises should be fitted with a grease separator complying with BS EN1825-1 and designed in accordance with BS EN1825-2 or other effective means of grease removal. BS EN1825 is the European standard for commercial gravity grease separators. Other effective means include mechanical grease removal equipment and biological or bacterial dosing systems which break down grease.