Toluene
C₆H₅CH₃·Affects brain, kidneys, liver
A common gasoline-derived solvent in the BTEX family. Contaminates groundwater near gas stations, refineries, and industrial sites.
C₆H₅CH₃
EPA limit
1 mg/L (MCL)
Most at risk
Households on private wells near petroleum operations or chemical plants
Found in
City water · Well water · Industrial areas
AquaOx filters
YesActivated coconut shell carbon
What it does to you
Health effects
Toluene primarily targets the central nervous system. Chronic exposure causes tiredness, memory loss, headaches, and impaired motor coordination; severe exposure can cause permanent neurological damage. Industrial solvent abuse studies (huffing) have established its neurotoxicity at high doses, and lower chronic exposure through drinking water is regulated to keep levels well below the threshold for neurological effects.
Liver and kidney damage are documented at sustained moderate exposure. Toluene also crosses the placenta and is associated with developmental effects when pregnant women are exposed at high levels.
Unlike its close chemical relative benzene, toluene is not classified as a human carcinogen. The EPA's MCL of 1 mg/L is set to protect against the non-cancer chronic effects.
Where it comes from
How it gets into your water
Toluene is one of the BTEX compounds (benzene, toluene, ethylbenzene, xylenes) found in gasoline, making up roughly 5 to 7 percent by volume. The dominant contamination route is leaking underground storage tanks at gas stations, where decades-old steel tanks corrode and release fuel into groundwater.
Industrial sources include paint and coating manufacture, printing operations, adhesives production, and chemical synthesis where toluene serves as a solvent or feedstock. Spills and improper disposal at these facilities can reach groundwater and migrate into nearby wells.
Gas stations
Leaking underground storage tanks
Paint & coatings
Manufacturing and disposal
Contaminated wells
Near petroleum or chemical sites
Printing & adhesives
Industrial solvent discharge
Find out for yourself
Is it in your water?
All public water utilities test for toluene and publish results in the annual Consumer Confidence Report. Most municipal systems report non-detect or trace levels well below the 1 mg/L MCL.
Private well owners near gas stations, fuel terminals, industrial corridors, or known petroleum spill sites should specifically request a BTEX or VOC panel. Toluene often appears alongside benzene, ethylbenzene, and xylenes because they share the same gasoline source.
The fix
How AquaOx filters it
Activated carbon is the EPA's recommended best-available technology for filtering toluene from drinking water. The Centaur catalytic carbon and coconut shell carbon stages in The AquaOx capture toluene through adsorption, with independent testing showing reductions above 95 percent across the BTEX family.
Because The AquaOx is a whole-house system, it also filters toluene from shower and bath water, where vapors otherwise contribute to inhalation exposure.