Arsenic in Water
The short answer on arsenic
Arsenic's federal limit is 10 ppb, and long-term exposure above it is a documented cancer risk — this is the contaminant worth taking seriously. The removal trap almost nobody explains: arsenic arrives in two chemical forms. As(V) filters out well with the standard media; As(III) — uncharged, common in low-oxygen wells — slips through most of them and must be oxidized first. Reverse osmosis (NSF/A… The details — sources, official limits and honest removal methods — are in the complete guide: The complete arsenic guide.
How to remove arsenic — what actually works
| Technology | Where it lives | What to demand on paper |
|---|---|---|
| FerrIX A33E | Point-of-use or whole-house system per spec | Named NSF/ANSI protocol or third-party lab sheet for the exact model |
| Nano Titanium Oxide | Point-of-use or whole-house system per spec | Named NSF/ANSI protocol or third-party lab sheet for the exact model |
| Activated Alumina | Point-of-use or whole-house system per spec | Named NSF/ANSI protocol or third-party lab sheet for the exact model |
| RO | Point-of-use or whole-house system per spec | Named NSF/ANSI protocol or third-party lab sheet for the exact model |
If a listing claims arsenic reduction and cannot name the standard or show the lab sheet, assume it does not have one. That single check filters out most of the market.
Can your refrigerator filter handle arsenic?
No — standard carbon cartridges are not engineered for it. The technologies above are the ones that address it; your fridge filter still does its own job (chlorine, taste, and with a 53 claim, lead and cysts). Fridge cartridges are built for chlorine, taste and odor (NSF/ANSI 42), plus lead and cysts on certified 53 tiers. If arsenic is your concern, keep the fridge cartridge for what it does well and put the right technology where you drink: see what your fridge model takes, then match the removal stage to the contaminant.
Often found together
- Fluoride in water — same source profile or shared treatment media; check your test report for the neighbor line items.
Arsenic questions, answered straight
Does boiling water remove arsenic?
Boiling is a concentration step, not a filter: water leaves as steam and whatever is dissolved stays behind, so levels rise by roughly the volume lost. The only heat-based method that works is distillation — capturing and condensing the steam. For arsenic specifically, see the full guide.
Is my refrigerator water filter enough for arsenic?
No — standard carbon cartridges are not engineered for it. The technologies above are the ones that address it; your fridge filter still does its own job (chlorine, taste, and with a 53 claim, lead and cysts). Match the technology to the contaminant, not the badge on the box.
How do I find out my actual arsenic level?
On city water, your utility's annual Consumer Confidence Report lists it free. On a well, a lab mail-in panel is the reliable route — the test-first card above links our guide to reading the results.
What removes arsenic from drinking water?
The technologies with a track record for arsenic: ferrix a33e, nano titanium oxide, activated alumina. Claims worth having come with a named standard (NSF/ANSI protocol or third-party lab sheet) — buy where the certificate names the exact part number.
Go deeper
Every contaminant, one page each
48 water problems from EPA primary, secondary and unregulated lists — sources, official limits, and which filters actually work (and which honestly don’t). Browse the Water Problems A–Z →