Kitchens face three challenges from cooking oils; storing them, preventing them accumulating on cooking surfaces and extraction ducts, and preventing them entering the drains from sinks and dishwashers.
Discoloured and contaminated cooking oil in deep fryers must be removed and replaced every few days. If you have commercial quantities, both fresh supplies and spent oils must be stored safely until collected by specially licensed companies (some is filtered and returned for cooking use, but most is converted to bio-fuel or animal feed).
Grease accumulating in vents and cooking surfaces is a fire hazard. By ignoring it you are not only at risk of fire, but invalidate your fire insurance too.
Grease from pots and plates heads for the drain. Though this may seem the smallest of the three risks, it is actually the most common cause of problems. Fat solidifying in drains can leave you unable to trade for days. If it blocks the sewer you are liable for the costs of the repair – enough to close down the business. Obstructed sewers cause roads to flood and sewage to leak into neighbouring homes and businesses, exposing you to compensation claims.
Legal requirements
Properly recycled, one litre of used oil can produce sufficient energy to make 240 cups of tea. Down the drain it’s a threat to rivers and the cleanup operation increases our water bills.
As well as fines, bills and compensation awards, you can face a prison term for improper handling of any significant quantity of oils or grease. In fact, the amount of legislation concerning grease and oils in a commercial kitchen is probably more than that governing engine grease and motor oil in a garage.
The main body of legislation is the Environmental Protection Act of 1990, but a host of other regulations can apply to kitchens, waste disposal companies and recycling businesses.
Grease traps
Grease traps for commercial kitchens are common sense. Fitted onto the drain pipe they separate it from the ordinary waste water (see examples at https://www.ukgreasetrapsdirect.co.uk/). Grease is then removed at regular intervals, and stored in a safe way until collected by a licensed disposal company.
Why not do it yourself?
Without a grease trap you risk E.coli, salmonella, campylobacter jejuni, fire, rodent and insect infestations, cracked drains, burns from cleaning chemicals, spillage and, of course, prosecution.