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Is Used Oil Hazardous Waste?

June 14, 2023

This blog entry answers common questions concerning the safe disposal of used oil—both large and small amounts and if used oil is hazardous waste. Q&As include:

1. What is the EPA definition of used oil?

2. What types of businesses generate used oil?

3. How do you dispose of used oil?

4. Can you recycle used oil?

5. Is used oil a hazardous waste?

6. What’s universal waste?

7. What’s the difference between a “listed” and a “characteristic” waste? 

8. How do you safely and legally store used oil offsite?

9. How do you safely and legally move used oil offsite?

10. By what processes can used oil be recycled?

11. Where can you get help recycling used oil?

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1. What is the EPA definition of used oil?

Short answer: Used oil is any petroleum-based oil or synthetic oil that has been used and thereby contaminated by physical and or chemical impurities. E.g., chemicals, dirt, halogens, metal scrapings, solvents, or water that find their way into the oil so that it no longer performs well. 

Longer answer: A substance must meet three criteria for it to be considered “used oil” by the EPA. They are:

  1. Origin. It has been refined from crude oil or made from synthetic materials.

  2. Use. It has been used as a lubricant, hydraulic fluid, heat transfer medium, buoyant, or something similar. 

  3. Contamination. It contains residues and contaminants generated from handling, storing, and processing.

In regard to (b), oils such as bottom cleanout waste from virgin fuel-oil storage tanks or virgin oil recovered from a spill do not meet the EPA definition of used oil because—technically—they have never been “used.” Ditto for oils used only as cleaning agents or solvents, as well as certain petroleum-derived products (e.g., antifreeze and kerosene). 

2. What types of businesses generate used oil?

As you might guess, the EPA considers you a “used oil generator” if you operate as a mechanic, car repair shop, service station, quick lube shop, motor pool, or boat marina. But less obviously, you might fall into this category if yours is a metalworking company or even a grocery store. 

Yet, there are exceptions. 

E.g., you’re excluded from waste oil generator status if you’re a farmer who produces less than an average of 25 gallons of used oil monthly. Also, if you’re Jay Leno. I.e., you’re an individual who owns numerous personal vehicles (or personal equipment) and thereby produces a lot of used oil secondary to their maintenance. Before proceeding one way or the other, you should get expert advice.

3. How do you dispose of used oil?

You don’t dispose of used oil. In virtually all cases, you should recycle used oil (See Q.4). And make sure that all your employees understand that used oil should never be poured down the drain or onto the ground. Neither is it permissible to burn oil to get rid of it. 

4. Can you recycle used oil?

Yes. Recycled oil might be used for its original assignment or for a completely different purpose. [E.g., used motor oil that’s been re-refined is available for sale at your local auto-care shop, and it meets all API and OEM performance standards (see source). Or in industry, certain oils can be filtered onsite and used over again.]

Factoid: Refined oil into a lubricant-quality product requires only a third of the energy that refining virgin oil requires. Another way to look at it: it takes 42 gallons of crude oil to produce 2.5 quarts of a lubricant-quality product—but only a single gallon of used oil to do the same (see source).

5. Is used oil a hazardous waste?

No. The EPA classifies used oil as a universal waste (See Q.6). But you have to be careful to keep it that way because it quickly becomes RCRA hazardous waste if it’s inadvertently mixed with a “listed” or “characteristic” waste (See Q.7). This would be an expensive mistake. How?

Suppose you mix a gallon of stale gasoline with a 55-gallon drum of used oil, per the EPA. In that case, you now have 56 gallons of hazmat and are in need of hazardous waste transportation, storage, and disposal—where you started with only one. And recycling used oil, thus contaminated, is not an option. So, before you mix anything with that used oil—get expert advice.

6. What’s universal waste?

The EPA created the Universal Waste subcategory for certain kinds of waste commonly generated by households, businesses, and industry—along with regulations that purportedly streamline the rules surrounding their waste disposal. It did so to ease the regulatory load on retail stores and other generators needing to collect and transport such waste to a treatment facility, to promote the collection and recycling of it, and to encourage the development of municipal and commercial programs to reduce the amount of waste in landfills or incinerators (see source).

7. What’s the difference between a “listed” and a “characteristic” waste? 

  • Listed. There are more than 500 substances deemed harmful to human health and or the environment by the EPA if not managed properly. They are published in the Code of Federal Regulations (40 CFR Part 261) across four separate lists. Thus, “listed waste.”

  • Characteristic. If a waste isn’t “listed,” it might be considered hazardous for one or more of its characteristics (i.e., ignitability, corrosivity, reactivity, or toxicity). Therefore, “characteristic waste.”  

8. How do you safely and legally store used oil offsite?

Used oil tanks and containers for storage don’t need to be RCRA permitted, so long as they have labels and are in good condition. I.e., not rusting, leaking, or otherwise deteriorating. Storage of used oil in lagoons, pits, or surface impoundments is RCRA prohibited (see source).

9. How do you safely and legally move used oil offsite?

You need to engage a properly-licensed hazardous waste transportation company to pick up from your site for ultimate delivery to used oil re-refiners, processors, or burners. Before getting there, it might languish at a used oil collection center, which is a facility that accepts small amounts of used oil, storing it until there’s enough to ship elsewhere for recycling. 

10. By what processes can used oil be recycled?

Used oil can be reconditioned on-site, re-refined, or processed & burned.

  1. Reconditioned onsite. In this process, used oil impurities are removed. While this doesn’t restore the used oil to its virgin condition, it can nevertheless be reused for its original purpose, and in doing so, it can be recycled more than once. 

  2. Re-refined. This involves treating the used oil as if it were virgin, similarly removing impurities so it can be used as a base stock for a new lubricating-quality product. This also can be done more than once. 

  3. Processed & burned. Here, water and particulates are removed so that the used oil can be burned, providing about as many BTUs as normal heating oil. This form of recycling is less preferable than (1) or (2) because the used oil is only reused once. 

11. Where can you get help recycling used oil?

Hazardous Waste Experts can help you with all facets of used oil management, safely and efficiently collecting and transporting your used oil to ensure full RCRA compliance. 

Whether you require regular container pick-ups or need an emergency pump-out, contact us today or call (425) 414-3485.

Disposal of hazardous waste doesn’t have to be painful.