According to the Environmental Protection Agency (EPA), oil pollution is the most commonly reported type of water pollution, causing approximately 16 percent of all pollution incidents each year. Oil pollution can have severe negative impacts on both the environment and human population. When oil enters the soil or bodies of water, it harms plants, animals, and humans by contaminating groundwater and, as a result, destroying natural habitats and compromising the safety of drinking water.

It doesn't take a lot of oil to cause major problems. Because of the way it spreads, even a small amount (10 liters) can completely cover one hectare of water surface.

Used oil, moreover, can have additional hazardous properties. Engine oil, for instance, is classified as a carcinogen. Oils should, therefore, be stored and disposed of with great care.

Types and Sources of Oily Waste

In the domestic setting, only two types of oils are typically used: vegetable-based oil for cooking, and engine oil for vehicle or machine maintenance (find out How to Safely Change Engine Oil).

While restaurants or bakeries will also use cooking oils and garages or workshops will use a significant amount of engine oil, commercial and industrial operations also use a wider range of oil products. Industrial machinery may require hydraulic fluid, lubricants, or emulsified cutting oils. Transformers also use specialist oils that contain polychlorinate biphenyls (PCBs), a harmful toxin that persists in the environment.

Hazards Associated with Oily Waste

Prolonged or frequent contact with used oil or oily waste can result in:

  • Acute oral toxicity if ingested. Oily waste is considered toxic if it has an acute oral LD50 less than 2,500 mg/kg.
  • Acute dermal toxicity if contact with skin occurs. This may cause dermatitis and skin cancer, as well as other types of skin disorders. Oily waste is considered being toxic if it has an acute dermal LD50 less than 4,300 mg/kg.
  • Acute aquatic toxicity, especially to the marine environment. Oily waste is considered aquatically toxic if it has an acute oral LD50 less than 500 mg/kg.
  • Carcinogenicity if the oily waste contains one or more carcinogenic substances in concentrations greater than or equal to 0.001 percent by weight.
  • The risk of spillage. Companies that deal with oily waste should develop and implement an emergency pollution response plan so that immediate action can be undertaken in the event of a spill. For instance, keep a stock of absorbent materials such as sand on site and educate and train staff on how to make use of it.

Safe Handling and Storage

Avoid unnecessary contact with oily waste whenever possible. If not possible, adopt safe work systems and ensure that the appropriate personal protective equipment, such as non-permeable gloves, is supplied and worn. It is also essential to ensure that all oil wastes are stored safety to reduce the risk of pollution prior to disposal. Used oils and oil wastes can be stored in specially designed oily waste cans.

Keep all oily wastes in secure areas. The EPA recommends that, regardless of legal requirements, all waste oil storage facilities should be sited on an impervious base within an oil-tight secondary containment system, such as a bund. This bund must be capable of containing as much as 110% of the volume of the oil container.

Transporting Oily Waste

When transporting waste oils, care must be taken at all times to avoid spillage, especially when transferring the waste oil to the storage facilities. The EPA recommends that waste oil tanks and pipework be installed above ground whenever possible, since this makes it easier to perform regular maintenance checks. These checks allow potential leaks to be identified, which can prevent active incidents from occurring.

How to Properly Disposal of Oily Waste

In the household, small quantities of waste cooking oils can be disposed of via municipal waste collection services. Lubricating oils, such as those used in maintaining vehicles, should be placed in a container with a secure lid and taken to your local household recycling site for safe disposal. Never pour the oils down the drain.

For commercial operations, make sure that the business meets the legal requirements for producing or storing oily waste, collecting or transporting oily waste (carrier), or recycling or disposing as a waste receiver (consignee).

Waste mineral oils and waste cooking oils can be treated to recover valuable components or to be used as fuel. For more information on this option, contact your nearest oil bank.

When Oil Becomes Waste

Waste oils can be hazardous to both humans and the natural environment. This is the case even when the original oil did not pose any serious threat, since the changes that occur to their properties and chemical compositions during their use is what often gives rise to health hazards. It is essential, then, to ensure good and safe practices are used when transporting, storing, handling, or disposing of oily waste.