By Mike Zahajko

Since the first gas station was built in 1905, fuel spills continue to be a common occurrence that causes millions in property damage, injury and deaths each year. Surprisingly, over 100 years later most gas station operators respond to spills with the same technology—ordinary kitty litter.

December 2020 data from the National Fire Protection Association (NFPA), recorded 4,150 fires at gas stations In the United States. These fires caused 43 injuries, $30 million in direct property damage and three deaths. Unsurprisingly, the item most often first ignited was “flammable or combustible liquids.”

To the untrained eye, most observers would say that spilled gasoline evaporates and goes away by itself. In a study published in the Journal of Contaminant Hydrology by researchers from Johns Hopkins, experiments were conducted to learn just how much gasoline is spilled and where it goes.  The results were surprising. The researchers estimate that 400 gallons of gasoline are spilled at the average gas station each decade.

Markus Hilpert, senior study leader and senior scientist, stated that “Gas Station owners have worked very hard to prevent gasoline from leaking out of underground storage tanks, but our research shows we should also be paying attention to the small spills that routinely occur when you refill your vehicle’s tank.”

Why is kitty litter or a similar OIL DRI absorbent used? It is cheap, readily available and absorbs spilled petroleum products. Is using kitty litter to treat a gasoline really an inexpensive option? The full cost of responding to a fuel spill must include the absorbent cost, labor and disposal.

  • Absorbent Cost: Kitty litter is inexpensive, ranging from 40 cents to 60 cents per pound.
  • Labor Cost: Treating a spill with kitty litter takes 20-30 minutes of labor, with another 20 minutes waiting to absorb. Assuming $15 per hour of employee cost, that adds $7.50 to the clean-up cost (more than 10 times the cost of the kitty litter). The time study included the time to cone-off the spill, spread the kitty litter, sweep up and bag the contaminated kitty litter and then dispose it into the hazmat barrel.
  • Disposal Cost: Containing and disposing of hazardous waste is expensive, typically ranging from $500-$1,000 for a drum. In some jurisdictions the “waste generator” owns the waste forever.


Hazardous Waste

Retail fueling sites are regulated by multiple environmental programs that vary by state. Typical hazardous wastes generated include waste fuel, clean-up absorbents (like kitty litter), spent filters and catchment basin waste. Out of the 150 different chemicals that make up gasoline, the four most identified as toxic to humans are benzene, toluene, ethyl benzene and xylene (BTEX).

Benzene content in gasoline is federally regulated. The current national benzene content in gasoline is about 1% as measured by volume. The reason for this strict regulation is that one gallon of gasoline can contaminate up to a million gallons of water, making it undrinkable.

In my 20-year experience, most gas stations do not have the necessary hazardous safety protocols required by state and federal regulations to handle hazardous waste. The absorbents used to respond to fuel spills are swept up and disposed of with all the rest of the trash. While not ideal, store personnel and leaders typically respond that they “double bag” the hazardous waste before putting it with the other trash. My favorite response when asking what site operators and leaders do with the waste over the years is: “The OIL DRI fairies come and take it.”



While warnings and fines are given by enforcement agencies to prevent the incorrect disposal of hazardous waste, the immediate risk comes from flammability. As the kitty litter absorbs the fuel spill, that kitty litter continues to be flammable for a long time. The “double bagged” waste builds up volatile organic compounds (VOC), creating a fire hazard. Of the more than 5,000 retail fueling site fires reported in the United States according to the National Fire Protection Association, more than 1 in 10 is caused by outside trash fires.

For site employees cleaning up the spill, flammability is a serious safety concern. During the process the kitty litter continues to be highly flammable, endangering the responder and customers in the spill area.


A Better Way

Despite being the most common solution for over 100 years, utilizing kitty litter on spills is expensive, labor intensive, unsafe and fails to correctly treat gasoline left behind in the concrete. Fortunately, new fire suppression technologies are available and are successful in addressing operational, safety and cost-related issues at gas stations around the globe.

The new technology uses micro-emulsion to suppress vapors to remove fuel flammability in less than three minutes. Additionally, active hydrocarbon-eating microbes can be used to bioremediate and break down remaining hydrocarbons in the surface over time. Bioremediation is an EPA-recommended process for using microbes to break down hazardous chemicals and contaminants.


Mike Zahajko is an industry speaker and the executive vice president for CAF, a leader in outdoor cleaning. Learn more about alternative spill solutions at