Confidence gleams from your grease-smeared forehead, and the pride of a job well done shines through your rust-speckled smile. You’ve just wrapped up some routine maintenance and finally found a moment to revel in the satisfaction that it brings. There’s something special about that connection between man and machine. Many of us think of our vehicles as an extension of ourselves, and consider it a privilege to care for them, but nobody ever talks about the dirty stuff.
One of the more nagging parts of doing your own maintenance is disposing of the waste. Oil, coolant, brake fluid, filters, or even old rags each have their own disposal guidelines. No matter how used to them we may be, they’re hazardous materials, and how we deal with them matters. What are the most common materials that we use? How can they impact the environment if they aren’t properly disposed of? And why does that matter?
Engine Oil and Filters
Engine oil is like the laundry of the garage. When you’re changing it like you should, it starts to stack up pretty quickly. We all drive so much these days that every three thousand to five thousand miles comes a lot faster than we ever expect it to. It’s easily the most common waste material among at-home mechanics and holds the most potential for environmental impact if it’s not handled correctly.
Most four-cylinder cars take around four quarts, or one gallon, of oil. One gallon of used oil can contaminate up to one million gallons of fresh water. Even when water sources are far away, the oil doesn’t evaporate or degrade when poured on the ground. It seeps into the soil and groundwater or is gradually washed into the storm drains and waterways over time.
To deal with it responsibly, drain it into a clean pan. A clean pan helps you find abnormalities in the color, consistency, and contents of your oil and ensures that you aren’t contaminating it with any other fluids. Also, keep fluids separate. The best practice I’ve found for this is to reuse old fluid containers for the same fluid that came in them originally. Used oil goes into an old oil bottle. Mixing used oil with coolant or brake fluid makes recycling practically impossible.
Find out where you can dispose of or recycle used motor oil near you. Most auto parts stores (Autozone, O’Reilly, etc.) will take used oil free of charge. They usually have a bin for drained oil filters as well.
Coolant
The active ingredient in coolant is ethylene glycol. It smells sweet, like maple syrup, and is a bright neon color, making it easy to spot. That’s not just to make it pretty, but because it is incredibly toxic. The results of mishandling it can be devastating in a multitude of ways.
Like oil, coolant should always be drained into a clean pan so that it doesn’t contaminate other fluids. If you’re dealing with a problem like a blown head gasket where the coolant and oil have already mixed, treat the mixture as hazardous waste that cannot be recycled. Coolant containers should always be clearly labeled and kept out of reach of children and animals. A few teaspoons of coolant is enough to kill most small animals, so keeping it inaccessible is best for everyone’s safety.
Check with your town or county about any hazardous waste days they may have. Not all auto parts stores accept coolant, though some may. A more consistent approach is to find out if your local municipalities have particular days or areas dedicated to accepting this type of toxic waste.
Brake Fluid
Brake fluid is a little different than the rest of these materials, and can be a little more difficult to dispose of. It’s hygroscopic, meaning it absorbs moisture from the air around it. It can be rapidly corrosive because of this trait. It’s also highly flammable.
Some auto shops or waste centers will accept brake fluid, but it is vital that you call beforehand so that you have a clear understanding of their requirements and stipulations. Small amounts can be solidified with kitty litter or oil dry and thrown into the regular trash, but it is still suggested that you check your local regulations. This option may not fly everywhere, and even in areas that allow it, it should only be used as a last resort.
Transmission Fluid, Gear Oils, and Power Steering Fluid
These generally fall under the same umbrella as engine oil, but can have a few different properties that set them apart, especially gear oil, which smells like Bigfoot’s body odor.
A common misconception about synthetic fluids is that they’re cleaner. However, when handled incorrectly, they can be just as harmful as conventional fluids. Most recycling centers will accept transmission fluids and gear oils, but it’s always better to check with your local center first.
Oily Rags or Pig Mats
This is where most of us lose our footing. We wipe down a work area, or clean up a spill, toss the rags into the trash or laundry, and just like that, hazardous materials are headed to the landfill or waterways. Instead, we should let the rags dry, ideally outside on a nonflammable surface. Once the rags are completely dry and not dripping in hazardous material, some areas will allow them to be thrown in the regular trash. If that’s not the case, or you’re uncomfortable with that, some counties have dedicated bins for things like this at their transfer stations or resource authorities.
Containers
Containers are also an area that we often neglect. Never use containers that are not meant for the waste fluid you’re dealing with. Milk jugs and soda bottles can quickly deteriorate when they come into contact with some chemicals in these fluids. On a good day, this mishandling would cause a massive mess in your garage or the trunk of your car, but in a worst-case scenario, you could potentially release gallons of harmful chemicals into the environment.
Make it a habit to reuse containers for whatever fluid they carried originally. For instance, only use old oil bottles for used oil. Never put oil in an antifreeze bottle, or vice versa. This keeps fluids from being mixed and prevents any kind of confusion if someone other than you ends up needing to dispose of the containers and their contents.
Keep It Clean
Part of the appeal of at-home maintenance is the freedom. No advisor is trying to upsell you on what you may or may not need due to mileage. There’s no customer lobby stocked with out-of-date magazines and stale coffee. There’s just you, your tools, and the job at hand.
But with great freedom comes great responsibility. The old-school way of doing things isn’t only outdated. It’s dangerous to our families, neighbors, and the next generation of gearheads riding their bikes through our communities. If we truly value our vehicles and respect the craft, we must treat the mess like it matters.
Proper disposal isn’t difficult nowadays. It just takes a little forethought and planning. So the next time you go to crack a drain plug loose, think beyond the job a little. Keep your drain pans clean. Store your fluids properly. Know your local resources and regulations. That way, we can keep our conscience as clean as our garage.