Everything You Need To Know About
Grease Traps In the UK

Grease traps have been around for more than 100 years. The concept is quite simple. Wastewater (usually from commercial kitchens)containing fats, oils and grease (or simply F.O.G.)enters a receptacle. F.O.G. does not mix with water and as F.O.G. is lighter than water it rises to the top. The clear water escapes under an outlet baffle whilst the grease remains trapped in the tank.

A traditional/manual grease trap needs to be opened and the trapped F.O.G. pumped out once a month.(an Automatic Grease Guardian removes the trapped grease automatically every day).Without the inclusion of a grease trap in commercial kitchens the health and safety of the establishment may be compromised.

Grease will cause blockages and foul odours if left untreated. It is common for government bodies to fine owners who fail to install some form of grease treatment and consequently create grease problems. Remember, your grease may be causing someone else trouble and it is usually not difficult to trace the source of the problem.

Drainage serving kitchens in commercial hot food premises should be fitted with a grease separator complying with BS EN 1825-1:2004 and designed in accordance with BS EN 1825-2:2002 or other effective means of grease removal. Grease Traps and Interceptors must be fitted by law to the following establishments

  • Restaurants
  • Hotels and guest houses
  • Pubs, bars and cafes
  • Commercial kitchens
  • Fast food restaurants and takeaways
  • Bakeries
  • Food processing
  • Hospitals and healthcare facilities
  • Manufacturing operations
  • Industrial process applications

Yes, the grease trap regulations in the UK are designed to safeguard the environment and public safety. If fats, oils, and greases (FOGs) produced by businesses like commercial kitchens are not properly managed, they can cause significant issues and problems within the UK sewage and water systems.

Environmental inspection agents or local authorities can request documentation related to the registration of waste carriers. Failure to provide these documents may result in a fixed penalty of £300 or prosecution.

Similar laws and regulations apply in Scotland, Wales and Northern Ireland to ensure that companies meet their obligations.

Most business owners want to avoid contributing to blockages out of a sense of duty and to prevent operational problems. However, it's important to be familiar with the specific laws in your country. In the UK, regulations can vary by region, but here are some general guidelines to be aware of:

  • Grease Removal: If your business serves hot food, your drainage system should have a grease separator or another effective means of grease removal installed (The Building Regulations 2010, Drainage and Waste Disposal, 2015 edition). Although Water and Sewerage Companies (WaSCs) cannot enforce the use of specific FOG management equipment, they can take action if discharges from your premises cause blockages in the local water system. It is your responsibility to prevent this.

  • Proof of Waste Collection: Authorities may require proof that kitchen waste is collected by a licensed contractor. Keep records of all collections to demonstrate compliance if needed (The Environmental Protection Act 1990).

  • Statutory Nuisance: Allowing food waste-related odours to permeate the environment can be considered a statutory nuisance, potentially leading to legal action against your establishment (Environmental Protection Act 1990).

  • Disposal of Cooking Oil: Leftover cooking oil cannot be sent to a landfill or used for animal feed. It must be collected by a licensed carrier (Animal By-Products Regulations).

  • Drainage Inspections: Local authorities can inspect commercial catering businesses to ensure proper drainage. You may be required to renew, repair, or clean your drainage system (Section 59 of the Building Act 1984).

Various sizes of units are available; first, decide whether you prefer a manual or automatic grease trap.

To determine the appropriate size, use our online sizing calculator. Just input your sink dimensions and list your fixtures.

Additionally, you can download our step-by-step sizing guide, which offers multiple methods for sizing your grease trap based on fixtures, flow rate, or the number of meals per day.

To comply with waste regulations, a food service establishment (FSE) must install grease trapping or grease retention equipment to reduce fat, oil, and grease (FOG) levels in the final discharge. Additionally, implementing Best Management Practices (BMP) within the FSE is crucial to minimise the production of FOG. It is imperative that the design, operation, and maintenance of grease management equipment align fully with the pertinent standards and the manufacturer's instructions. Equipment that is either undersized or oversized will fail to yield the necessary outcomes.

Passive Traps – Unfortunately, unless maintained every couple of weeks grease trap efficiency will drop and grease will escape or build up and overflow. This is common where the grease trap was undersized or business has expanded. You need to empty your system at least once a month but this can prove costly.

Perhaps an Automatic Grease Removal device should be considered. Grease Guardian can be installed at the source of the problem, i.e. potwash sinks, ovens etc. and will extract trapped grease each day preventing any grease build up that could result in a drop in efficiency. Enzyme/Bacteria systems – These systems may not break down the grease efficiently and allow the grease to build up.

Furthermore, they need to be topped up regularly, which can prove costly. Your local council may be unhappy that you are using such a system as it takes grease away from your premises only to see it reform somewhere else. Other Grease Removal devices though claiming high flow rates actually have very small tank sizes and therefore allow grease to escape easily. Many are made of plastic which is prone to leaks. A Grease Guardian protects you and the local environment and does not require enzymes or bacteria.

Yes. Most inspections come with a notice period, allowing you time to properly prepare your grease trap. However, surprise inspections can occur. To stay ahead, it's crucial to maintain your grease trap regularly. Inspectors will likely first ask to see your records of grease trap cleaning and maintenance, which are legally required to be up-to-date and readily available.

The inspector's main focus is to ensure the grease trap is functioning correctly, in good condition, and compliant with local regulations and standards. Key aspects they will check include:

  • Grease Accumulation: They will assess the amount of accumulated grease to ensure it is within the permissible range.
  • Solids Accumulation: Excess solids at the bottom of the trap can impede functionality, so this will be checked.
  • Components: The condition of baffles, inlets and outlets, seals, and other parts will be inspected for any damage to ensure they are in working order.
  • Cleanliness: Excessive build-up can cause odours and hinder performance. The inspector will evaluate cleanliness along with maintenance and cleaning records.
  • Water Flow: They will check for smooth water flow without blockages.
  • Size and Capacity: The grease trap must be appropriately sized for your establishment.
  • Ventilation: Proper ventilation is necessary to prevent gaseous odours and reduce health and safety risks.
  • Compliance with Local Regulations: The inspector will verify that your grease trap meets all required regulations.

For more information on Fats, Oils and Grease Management,
Check out's FOG Management Guide Here




  • Effortless Grease Removal: Our Automatic Devices remove captured grease so you don’t have to.
  • Cost Savings: Automatic Devices reduce the frequency of costly pump-outs and maintenance.
  • Efficiency: They ensure smooth operation and compliance with minimal manual intervention.

Choose Grease Guardian for a high-performance, hassle-free grease management solution.

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