Antimony
Sb·Affects liver, heart
A heavy metal used in flame retardants, solder, and PET-plastic manufacturing. Leaches into water from industrial discharge and from heated plastic containers. EPA MCL is 0.006 mg/L.
Sb
EPA limit
0.006 mg/L (MCL)
Most at risk
Industrial-area residents, well users near mining or smelting sites, people who reuse heated plastic bottles
Found in
City water · Well water · Industrial areas
AquaOx filters
YesKDF-55 + activated carbon
What it does to you
Health effects
The liver is the primary target organ for chronic antimony exposure. Long-term ingestion causes elevated liver enzymes, altered cholesterol metabolism, and in animal studies, liver tumors. Antimony also has cardiovascular effects, including elevated blood pressure and changes in heart muscle function at sustained exposure.
Acute exposure to high doses causes severe vomiting and gastrointestinal distress, historically used as the principle of emetic tartar (antimony potassium tartrate). The EPA set the 6 µg/L MCL based on lifetime exposure risk to the cardiovascular and hepatic systems.
Antimony trioxide is classified by the International Agency for Research on Cancer as possibly carcinogenic to humans (Group 2B), based primarily on inhalation studies in occupational settings.
Where it comes from
How it gets into your water
Antimony enters water from industrial discharge, particularly from antimony mining and smelting, lead-acid battery manufacturing, and from production of flame retardants, ceramics, glass, and solder. Antimony is also a common impurity in lead and copper plumbing.
PET (polyethylene terephthalate) plastic, the material most water and soda bottles are made from, is manufactured with antimony catalysts. Trace antimony leaches from PET bottles into the water inside, especially when bottles are heated (left in a hot car, for instance).
Some antimony enters surface water from coal-fired power plants and from natural weathering of antimony-bearing minerals in certain geological settings.
Lead-acid battery manufacturing
Antimony alloyed with lead in plates
Smelting and mining discharge
Antimony and lead mining operations
Solder and pipe impurities
Antimony in older lead solder
Flame retardant production
Antimony trioxide manufacturing waste
Find out for yourself
Is it in your water?
Antimony is included in the comprehensive inorganic package most certified labs offer for well-water testing. Utilities test antimony and report results on their Consumer Confidence Reports.
Detection of antimony at or above the MCL is uncommon in finished tap water, but residents near antimony mines (largest US deposits are in Idaho, Nevada, and Alaska), battery plants, or flame-retardant manufacturing facilities should test their water specifically. Private well owners within a few miles of these industrial sources have elevated risk.
The fix
How AquaOx filters it
AquaOx's KDF-55 copper-zinc media reduces antimony through redox chemistry, converting soluble antimony ions into insoluble forms trapped in the filter bed. The activated carbon stages add adsorption capacity for residual antimony compounds.
For homes near documented industrial antimony sources, AquaOx recommends adding a point-of-use reverse osmosis unit at the kitchen sink as a second barrier specifically for drinking and cooking water.