Inorganic
Selenium in your water
Is Selenium in drinking water dangerous?
It depends on the level and how long you're exposed. The EPA legal limit (MCL) for Selenium is 50 ppb. Meeting the legal limit isn't the same as zero risk — test your water to know your level.
How do you remove Selenium from water?
Selenium is treated by Water Softener and Reverse Osmosis. Choose a system independently certified to NSF/ANSI standards to reduce Selenium, and test your water first to confirm the level.
Source: EPA MCL / MCLG; WHO guidelines; NSF/ANSI · 2026
Health effects
Selenium is a naturally occurring element that is a necessary nutrient at trace levels but toxic in excess. Long-term high exposure can damage the nervous system, hair, and nails. It enters water from natural deposits and from irrigation drainage.
The health-based goal vs. the legal limit
The federal legal limit (MCL) is the maximum allowed by law. The health-based goal (EPA MCLG / WHO) is a health target — it is often stricter than the legal limit, and it is not itself a legal limit.
Health-based goal (EPA MCLG / WHO)
No health-based goal set
Federal legal limit (MCL)
50 ppb
Source: EPA MCL / MCLG; WHO guidelines · 2026
Not affiliated with or endorsed by EWG.
What removes Selenium
Ion exchange
Water Softener
Swaps the calcium and magnesium that cause hard water for sodium — so scale stops forming.
Look for: NSF/ANSI 44 certification
How it works→Semipermeable membrane filtration
Reverse Osmosis
Pushes water through a fine membrane that removes the dissolved solids most filters miss.
Look for: NSF/ANSI 58 certification
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Is Selenium in your water?
Check your city's public record, then book a free 30-minute test to confirm what's in your home.