Antimony
Uncommon, and when it appears it usually came from a pipe, a solder joint or a plastic.
- Safe range
- 0 – 0.006 mg/L (US EPA primary standard, with the health goal set at the same figure.)
- Measured in
- mg/L
What it is
Antimony is used in solder, in some brass and metal alloys, in flame retardants, and as a catalyst in making PET plastic. In drinking water it most often comes from plumbing materials rather than from the ground.
Why it matters
The health concern from long-term exposure is raised cholesterol and lowered blood sugar, with gastrointestinal effects at higher levels. It is rare enough that a detection is worth investigating as a materials question — what is the water touching between the main and the tap — rather than assumed to be geological.
How to measure it
A laboratory. It is on comprehensive metals panels and absent from short ones.
Certified laboratory, mail-in kit
- How trustworthy
- Reference grade
- Cost
- Most expensive
- Effort
- Careful sampling, then days or weeks of waiting
You are posted bottles and instructions, you fill them exactly as told, and you post them back. Weeks later a report arrives with figures nobody has to interpret by eye. This is what a result you intend to act on should be built from.
Check the analyte list before ordering — antimony is one of the first things trimmed from a budget panel.
Where to find it: State-certified drinking water laboratories; your state's certification officer keeps the list, and many public health departments will point you at one.
Your utility's annual water quality report
- How trustworthy
- Reference grade
- Cost
- Free
- Effort
- A few minutes of reading
Every community water system in the US has to publish one each year, free, listing what it found and what the limits are. It is real laboratory data about the water leaving the plant and travelling the mains. What it cannot describe is your own plumbing.
Regulated and published annually.
Where to find it: Your water bill, your supplier's website, or the EPA's index of reports. It is also called a Consumer Confidence Report or CCR.
Taking the sample
For several of these the sample is where the error is, and no instrument recovers from a bad one.
- • Take a first-draw and a flushed sample if you can. Antimony from plumbing shows a large difference between the two; antimony from the source does not.
Further reading: US EPA: National Primary Drinking Water Regulations, the enforceable health-based limits
If it is too low
Nothing to act on.
- • No action needed.
If it is too high
Long-term exposure has been associated with cholesterol and blood-sugar effects. Worth tracing to its source, which is usually something in the plumbing.
- • Flush before drawing drinking water, and take a flushed sample to see whether the level drops — that separates plumbing from source.
- • Reverse osmosis and distillation both remove it.
- • Look at recent plumbing work; new solder and fittings are a plausible cause of a new detection.
Common questions
Does antimony leach from plastic water bottles?
Antimony is used as a catalyst in making PET, and very small amounts can migrate into the contents, more so when a bottle is stored hot. The levels reported in studies are generally far below the drinking water limit, but it is a real reason not to leave bottled water in a hot car.
Is antimony common in well water?
No. It is one of the rarer detections on a panel, and when it does turn up the plumbing is a more likely explanation than the aquifer.
WiseWaterGauge helps you record and understand your own readings. It is not a substitute for a certified laboratory test, and nothing here is medical or regulatory advice. If a health parameter is out of range, confirm it with an accredited lab and speak to your water provider.