1,4 Dioxane

EPA's Integrated Risk Information System classifies 1,4 Dioxane as: likely to be carcinogenic to humans. EPA's stated basis: "Based on the following findings: (1) inadequate evidence of carcinogenicity in humans, and (2) sufficient evidence in animals (i.e., hepatic tumors in multiple species [three strains of rats, two strains of mouse, and in guinea pigs]; mesotheliomas of the peritoneum, mammary, and nasal tumors have also been observed in rats following 2 years of oral exposure to 1,4- dioxane)." EPA's oral reference dose for 1,4 Dioxane is 0.03 mg/kg-day, based on a critical effect of "Liver and kidney toxicity". EPA has not set a federal drinking-water limit (MCL or MCLG) for 1,4 Dioxane; IRIS assesses a chemical's toxicity, not the amount permitted in tap water.

Source: EPA IRIS — Integrated Risk Information System (IRIS) (retrieved 2026-07-28)

Water filters certified under the following NSF standards are effective at removing 1,4 Dioxane:

1,4 Dioxane has been detected above EPA health guidelines in 2 cities serving 0.0M people across the US.