What's The Correct Way To Dispose Of Old Cooking Oil?

Yes, bad fats are in the news again! Not for their impacts on human obesity this time, but for clogging of a different kind. A fatberg - a rock-solid mass of oil, disposable wipes, diapers, condoms and tampons is clogging London's sewerage system. 

The agglomeration of grease and garbage weighs roughly 130 tonnes and is expected to take workers 3 weeks to extract. While this is not the first time London is faced with this floating menace, the current fatberg is ten times heavier than the last one found in 2013 and is the size of 11 double-decker buses! And London's not alone; New York has had its own fatberg face-off and it's not long before they start surfacing in other cities across the world.

A chunk of the fatberg extracted from London's sewers. Source: Wiki Commons.

A chunk of the fatberg extracted from London's sewers. Source: Wiki Commons.

Fatbergs form when grease from cooking oil and fats poured down kitchen sinks or toilets mix with paper and plastic waste (from tissues and tampons flushed down toilets) to form a congealed mass with the consistency of concrete. As more fat, grease and garbage accumulate on the putrid mass, it grows in size, blocks plumbing systems and inhibits the free flow of wastewater to sewage treatment plants. The result? All that stinking mess gushes out into our homes or onto the streets from where it flows into open water bodies such as lakes and pollutes them.

While London's men and machinery are at hard at work freeing up the city's drains of fatbergs and non-biodegradable waste, you can remember never to pour cooking oil into the kitchen sink or down the toilet. No amount of hot water or soap poured down the sink can prevent oil from sticking to the insides of pipes and clogging them.

A fat-clogged drainage pipe  Source

A fat-clogged drainage pipe Source

The following items must never be poured down the sink or flushed down the toilet:

  • Cooking oil, ghee, butter
  • Salad dressing, mayonnaise, cheese spreads
  • Milk and cream
  • Gravy, curry, sauces.
  • Food scraps

Here's what you can do to keep fatbergs at bay

1. Start composting: Home composting units, especially anaerobic ones, do a great job of decomposing dairy and cooked food of all kinds. Invest in a home composting system so you don't have to throw your food waste into the drain or the garbage.

2. If you have access to a garden or soil patch, empty the oil or greasy leftovers directly into the soil.

3. Before washing greasy plates and utensils, wipe them clean with a paper napkin and dispose of it in the trash.

4. Scrape the fat, grease and leftover food from plates and utensils into the organic waste bin before washing them. Oils such coconut oil harden on cooling and are easier to scrape off.

5. Use strainers in sinks to catch any food particles and empty the contents into the bin for organic waste.

6. Cool used cooking oil and oily gravies to room temperature, pour them into plastic or glass containers and dispose them in the dry waste bin.

7. Use less oil: Reduce the amount of oil used in cooking, deep fry less often, and experiment with baking and alternative cooking techniques that require less/ no oil.

8. Reuse oils carefully: While reusing of cooking oils is generally frowned upon, if oil is used carefully, it can be recycled a few times before being thrown away. Every time you deep fry, use a fine cloth to filter the cooled oil and remove any bits of food and batter floating in it. This way, you reduce chances of these crumbs burning and turning the oil rancid. Store the filtered oil in an airtight container in a cool, dark place, and reuse it quickly. Look for signs the oil is going bad:
- foam on the surface
- a fishy or rancid smell
- a dark, cloudy appearance.

9. Maintaining oil at the right temperature during the cooking process prevents oil from breaking down and helps it last longer.

10. Remember never to flush wet wipes, tissue, diapers, condoms, tampons and sanitary pads down the toilet.