How to Properly Dispose of Used Vegetable Oil

How to Properly Dispose of Used Vegetable Oil


As I cook more at home, I find myself generating more and more used cooking oil from frying foods. While pouring the oil down the drain may seem convenient, it can lead to serious problems with clogged pipes and sewage treatment systems. Learning how to properly dispose of used vegetable oil is important for home cooks. In this article, I will provide a thorough overview of recommended practices for disposing of used cooking oils and grease.

Dangers of Pouring Oil Down the Drain

Pouring fats, oils and grease down the drain is an easy habit to develop in the kitchen. However, this causes several problems:

  • Clogged pipes – Oil and grease can build up and block pipes, both under the sink and further down the sewer line. This can lead to costly plumbing issues and repairs.

  • Sewage backup – Sewage backup is caused when grease accumulates in sewer pipes and congeals into blockages. Raw sewage can then back up into homes, streets, rivers and lakes.

  • Environmental harm – Oil dumped down drains flows into sewage treatment plants that are not equipped to remove it. The oil then enters and pollutes waterways.

To avoid these problems, proper disposal of used cooking oils is essential.

How to Collect Used Cooking Oil

Before I can properly dispose of used oil, I first need to collect and store it properly. Here are some tips:

  • Allow oil to cool completely before handling. Hot oil can easily burn skin.

  • Pour cooled oil into a sealable container – I like to use empty milk jugs or yogurt containers. This prevents spills and leaks during storage.

  • Never mix oil with other liquids – Keep only pure used oil in the container so it can be recycled.

  • Store in a cool, dark place – Heat and light can cause oil to become rancid. The refrigerator is a good storage spot.

  • Clearly label the container as “USED COOKING OIL” so it is not mistaken for something else.

Proper collection and storage makes it much easier to deal with used oil responsibly.

Recycle Used Cooking Oil

The best way to dispose of used cooking oil is to recycle it. Many municipal household hazardous waste collection centers accept used cooking oil. Some will even provide free containers to collect the oil and drop it off.

I like to call my local recycling center to ask about their used oil recycling program. Many communities offer periodic collection days specifically for household oils and fats. The collected oil can be converted into useful products like biodiesel fuel. Recycling oil is the most environmentally friendly disposal method.

Put in the Trash as a Last Resort

If a recycling program is not available in my area, I can dispose of small amounts of used cooking oil in the regular trash. However, this should only be a last resort if recycling is not an option.

To prepare used oil for landfill disposal:

  • Allow oil to fully cool and harden. Pouring liquid oil into trash bags can lead to leaks and spills.

  • Mix oil with an absorbent material like cat litter, sawdust, or shredded paper. This helps soak up the oil and solidifies it.

  • Place the oil-absorbent mixture into a sealed container or bag before putting in the trash. This contains any residue and prevents leaks.

  • Never put more than 1 cup of oil product in the trash at a time. Any more can seep out of trash bags and cause problems.

With proper preparation, limited amounts of used cooking oil can go into the regular trash. But recycling should always be the first choice.

Avoid Hazardous Drain Disposal

As noted earlier, pouring used cooking oil down the drain can create expensive plumbing issues and environmental harm. Never dispose of oil by pouring it down sinks or toilets.

Some other disposal methods to avoid:

  • Dumping oil into storm drains – This flows directly into waterways and quickly pollutes ecosystems.

  • Adding to compost piles – Oil cannot properly break down and compost. It will contaminate the whole pile.

  • Using as a weed killer – Oil application harms all plants, not just weeds. It also seeps into soil and groundwater.

Only rain and gray water should go down drains. Used cooking oil requires special handling for safe disposal.


Learning how to properly dispose of used cooking oil is an important responsibility for home cooks like myself. We must be diligent to avoid clogged pipes, sewage backups, and environmental damage. Recycling oil through community hazardous waste programs is the ideal disposal solution. With proper storage and limited landfill trash disposal as a backup plan, I can keep used vegetable oil out of drains and water supplies. A small amount of planning goes a long way to protect plumbing and the planet!