Benz(a)anthracene
C₁₈H₁₂·Affects liver, lungs
A polycyclic aromatic hydrocarbon (PAH) produced by combustion. Found in water contaminated by coal-tar runoff, asphalt sealants, and creosote.
C₁₈H₁₂
EPA limit
Regulated under PAHs (no separate MCL; benzo(a)pyrene used as marker at 0.0002 mg/L)
Most at risk
Households near parking lots sealed with coal-tar, industrial combustion sites, or creosote-treated wood
Found in
City water · Well water · Industrial areas
AquaOx filters
YesActivated coconut shell carbon
What it does to you
Health effects
Benz(a)anthracene is one of the polycyclic aromatic hydrocarbons (PAHs) the EPA tracks as a group because they share carcinogenic mechanisms. The International Agency for Research on Cancer classifies benz(a)anthracene as Group 2B (possibly carcinogenic to humans). The compound is metabolically activated in the body to reactive intermediates that bind DNA and cause mutations linked to liver and lung tumors in animal studies.
Chronic exposure also produces non-cancer effects on the liver and immune system in laboratory studies. PAHs as a class are documented developmental and reproductive toxicants.
The EPA does not set an individual MCL for benz(a)anthracene; PAH regulation in drinking water uses benzo(a)pyrene as the indicator compound at 0.0002 mg/L. The presence of one PAH typically signals the presence of others.
Where it comes from
How it gets into your water
Benz(a)anthracene is a combustion byproduct. It enters water through stormwater runoff from urban surfaces, particularly parking lots and driveways sealed with coal-tar pavement sealants, which can contain PAHs at percent-level concentrations. Asphalt pavement, vehicle exhaust deposition, and wood smoke all contribute background loading.
Industrial sources include coal-tar production, aluminum smelting, coke ovens, and creosote-treated wood operations (railroad ties, utility poles, marine pilings). Old gasworks and former manufactured-gas plant sites are common groundwater PAH sources. Oil spills and refinery discharge add to the load.
Coal-tar sealants
Parking lot and driveway runoff
Creosote-treated wood
Railroad ties, utility poles, pilings
Contaminated wells
Near former gasworks or industrial sites
Combustion sources
Coke ovens, aluminum smelting
Find out for yourself
Is it in your water?
Public water utilities test for PAHs as part of the regulated contaminant list, using benzo(a)pyrene as the marker compound on Consumer Confidence Reports. Detections are uncommon in well-run municipal systems with protected source water.
Private well owners near former manufactured gas plants, creosote yards, coal-tar facilities, or aluminum smelters should request PAH testing. EPA Method 525 covers benz(a)anthracene and other PAHs at sub-microgram-per-liter detection limits.
The fix
How AquaOx filters it
Activated carbon is highly effective at filtering PAHs including benz(a)anthracene. The Centaur catalytic carbon and coconut shell activated carbon stages in The AquaOx adsorb PAHs strongly because of their large, hydrophobic molecular structure, which binds tightly to carbon surfaces.
For households on wells with confirmed PAH contamination, we recommend pairing The AquaOx with the under-sink RO at the kitchen tap for an additional barrier on drinking and cooking water.