Inorganic
Perchlorate in your water
Is Perchlorate in drinking water dangerous?
It depends on the level and how long you're exposed. The EPA has set no federal legal limit for Perchlorate, but health-based goals (EPA MCLG / WHO) are often stricter, at 1 ppb. Meeting the legal limit isn't the same as zero risk — test your water to know your level.
How do you remove Perchlorate from water?
Perchlorate is treated by Water Softener and Reverse Osmosis. Choose a system independently certified to NSF/ANSI standards to reduce Perchlorate, and test your water first to confirm the level.
Source: EPA MCL / MCLG; WHO guidelines; NSF/ANSI · 2026
Health effects
Perchlorate comes from rocket fuel, explosives, and some fertilizers, and is also found naturally in arid regions. It interferes with the thyroid's ability to make hormones, which is especially concerning for pregnancy and infant development. There is currently no enforceable national drinking-water limit.
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)
1 ppb
Federal legal limit (MCL)
No federal limit set
Source: EPA MCL / MCLG; WHO guidelines · 2026
Not affiliated with or endorsed by EWG.
What removes Perchlorate
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 Perchlorate in your water?
Check your city's public record, then book a free 30-minute test to confirm what's in your home.