No one intends to spill drinks like coffee or milk in their car, but it happens every day. When a spill does occur, it's best to clean up the excess liquid immediately using paper towels or a clean cloth. Don't let it set.
No one plans for his or her car to stink, but stink happens. Sometimes it sneaks up on you, like a car's musty smell that builds after months in a damp garage. Sometimes it hits you in the face with the stench of a rotting, dead animal — because sometimes, the source of the smell is a rotting, dead animal.
A stinky car is bad for obvious reasons, but a stubborn stench can have effects that go beyond the immediate olfactory offense. It could actually reduce the resale value of your vehicle. And because your auto is a sealed environment that is frequently pressurized by its own HVAC system and left to bake out in the sun, the bad smells won't just go away on their own. In fact, they tend to get worse over time. Remember the "Seinfeld" episode in which his BMW was possessed by the aberrant body odor of a parking valet? Jerry was willing to give his German masterpiece away for nothing, simply to rid himself of the overpowering odor that seemed to infect everyone who came in contact with it.
What's Causing That Smell?
According to Kenneth S. Suslick, a chemistry professor at the University of Illinois at Urbana-Champaign who has written extensively about the chemistry of scent, humans perceive aromas through an array of millions of cells in the nasal cavity called the olfactory epithelium. The receptors of the olfactory epithelium bind to various airborne chemicals and fire neurons to communicate smell to the brain. Different sections of the olfactory epithelium are tuned to receive different types of odors, and the way we tell one scent from another is by the pattern of receptors that are triggered — complex ones trigger a variety of neurons that blend like dabs of color on a canvas.
Watch Video: How to Remove Cigarette Odors from Your Car
"The olfactory system evolved primarily to keep animals away from concentrations of bacteria," Suslick says. "We're most repulsed by gases that are produced as byproducts of these microorganisms." These gases can include amines (the ammonia smell of urine), hydrogen sulfide (rotten eggs), butyric acid (vomit, rotten milk), putrescine and cadaverine (rotting flesh). "There's really no way to stop bacteria from releasing these gases," he says. "They aren't under the control of the EPA, and they don't respect the Clean Air Act."
Other smells, such as smoke, skunk, mildew and fuel, are not the direct byproducts of bacteria, but can be especially difficult to eradicate because they permeate the entire vehicle — getting into the HVAC system and settling in all the fabrics of the car. Diane Barnes, president of a bioremediation and cleanup company called BioWorld Products in Visalia, Calif., has seen her share of customers afflicted with terrible automotive stink. "We've had people cry because of a smell," she says, "especially with a brand-new car. That's just heartbreaking."
Read: Is That 'New Car Smell' Harming You?
What's the First Step?
Cory Chalmers, owner of California-based Crime Scene Steri-Clean, has cleaned up cars after suicides, police pursuits, accidents and other messy situations. It may seem obvious, he says, but the most important thing when you're dealing with odor is to find the source and clean it up as soon as possible.
That's not always as easy as you might imagine. "We had a woman who left a whole chicken in her trunk and went away for a week while it baked in her car," Chalmers recalls. "We had to tear out the carpeting and get underneath to find where all the fluids leaked."
Chalmers warns that if something stinky finds its way through your carpeting, you're in for a lot more trouble, since there are plenty of holes under the vehicle floorboards, and plenty of places where organic matter can collect and fester. "Spilled milk, for instance, is a tough one," he says. "It will instantly find the lowest point in your car." He warns that if a spill soaks into the floorboards of your vehicle, you're going to want to hire a pro who can locate all the places in your vehicle where smells can hide.
To prevent things from getting to that point, many of the experts we've spoken to recommend keeping a towel handy in the vehicle at all times to soak up spills when they happen. "Dry it up as fast as possible before it sets," says Jon Farmer, general manager of Dakota Products, a maker of environmentally friendly cleaning supplies in Sioux Falls, S.D. For deep-set stinky stains, he recommends an enzyme-based cleaner, which breaks down and digests odor-causing stains.
