mineral

Barium

Reviewed for accuracy against EPA data and peer-reviewed literature · Updated May 2026

A naturally occurring metal found in rock and soil. Leaches into groundwater from natural deposits and is also present in some industrial discharge.

CAS 7440-39-3

EPA legal limit

2 ppm

Maximum Contaminant Level

EWG health guideline

No guideline

Science-based, stricter target

Health effects

Short-term exposure above 2 ppm can cause increases in blood pressure. Long-term exposure at high levels may cause cardiovascular effects. At the levels found in most U.S. drinking water, barium is not a significant health concern.

Where it comes from

Natural geological sources and industrial discharge from drilling operations and smelting.

How it's regulated

EPA MCL of 2 ppm.

How to filter barium

Not all filters address barium. Look for independently certified filters — NSF International certification means the removal claim has been independently verified.

Reverse osmosis (RO)NSF 58
NSF 58 certified RO system
Ion exchange resin

Frequently asked questions

What is barium?

A naturally occurring metal found in rock and soil. Leaches into groundwater from natural deposits and is also present in some industrial discharge.

What are the health effects of barium?

Short-term exposure above 2 ppm can cause increases in blood pressure. Long-term exposure at high levels may cause cardiovascular effects. At the levels found in most U.S. drinking water, barium is not a significant health concern.

Is barium regulated in drinking water?

EPA MCL of 2 ppm.

Where does barium come from?

Natural geological sources and industrial discharge from drilling operations and smelting.

How do I remove barium from tap water?

The most effective methods for removing barium are: Reverse osmosis (RO), NSF 58 certified RO system, Ion exchange resin. Look for NSF-certified systems — independent certification confirms removal claims have been verified.

Is barium in your water?

Enter your ZIP code to see the measured level in your specific utility.