The disposal of warm fats and grease in a liquid form or waste oil being poured down sinks and drains will give rise to blockages in sewers and drains. This page gives advice to commercial premises on how to prevent this.

The problem

Fats, oils and grease cause major problems to the sewerage system. When they are discharged down kitchen sinks or foul drains they cause sewer blockages and when discharged down rainwater pipes and gullies they cause pollution in local water courses.

There are approximately 200,000 sewer blockages and pollution incidents throughout England and Wales every year, of which up to 75% are caused by fat, oils and grease. Clearing these blockages cost millions of pounds a year. Businesses also risk blocking their drainage systems, which will result in loss of income due to cleaning up costs. These fat blockages result in sewer flooding, odour problems and the risk of rat infestations near your premises.

Top tips to dispose of fats and oils safely

  • Scrape or wipe plates, pans and utensils prior to washing (put the solid waste into the rubbish bin)
  • Keep oil and grease out of washing up water
  • Do not put cooking oil, fat or grease down the sink.
  • Use strainers in sink plug holes and put any collected food debris in the rubbish bin
  • Do not sweep solids into floor drains - put rubbish and food waste in rubbish bins
  • Consider fitting a grease trap and make sure that is regularly maintained
  • Do not dispose of oils, fat and grease at Civic Amenity sites (the tip)
  • Do arrange for oil to be collected by an approved and licensed waste contractor

Best practice for food businesses (Thames Water website)

Waste oil collection

Waste oil can be recycled into bio diesel, animal feeds, detergents, cosmetics, plastics and moulds. The oil should be stored in leak proof containers, which should be kept covered.

Disposal of Waste Cooking Oil - information on oil collections and those companies who will collect waste oil


Section 111 of the Water Industry Act 1991 makes it illegal to permit any substance, which may interfere with the free flow of the sewerage system, to pass down any drain or sewer connecting to a public sewer. This will include fats, oils and grease. This provision is enforced by Thames Water.

Our officers visit food businesses and under the Food Hygiene Regulations can assist that proper arrangements are made for the disposal of waste. This includes that proper arrangements are in places for the disposal of fats and oils.

Related websites

Waste cooking oil from catering premises (Food standards agency website)

Contact us

Food and Safety
Regulatory Services Partnership
Merton Civic Centre
London Road

Tel: 020 8545 3025