# Barium — EPA national recommended water quality criteria for human health: pollutant concentration thresholds For Barium, cas registry number is 7440393; water + organism criterion (µg/l) is 1,000; organism only criterion (µg/l) is —, verified against its source on 2026-08-17. - **Pollutant name:** Barium _(verified: appears in the quote below)_ - **CAS Registry Number:** 7440393 _(verified: appears in the quote below)_ - **Water + Organism criterion (µg/L):** 1,000 _(verified: appears in the quote below)_ - **Organism Only criterion (µg/L):** — _(verified: appears in the quote below)_ ## What the source says > Barium | 7440393 | 1,000 | — | 1986 ## Source - https://www.epa.gov/wqc/national-recommended-water-quality-criteria-human-health-criteria-table Last verified: 2026-08-17. Review by: 2028-08-16. Part of [EPA national recommended water quality criteria for human health: pollutant concentration thresholds](https://referencesource.org/epa-water-quality-criteria-human-health/).