# Isophorone (P) — EPA national recommended water quality criteria for human health: pollutant concentration thresholds

For Isophorone (P), cas registry number is 78591; water + organism criterion (µg/l) is 34; organism only criterion (µg/l) is 1,800, verified against its source on 2026-08-17.

- **Pollutant name:** Isophorone (P) _(verified: appears in the quote below)_
- **CAS Registry Number:** 78591 _(verified: appears in the quote below)_
- **Water + Organism criterion (µg/L):** 34 _(verified: appears in the quote below)_
- **Organism Only criterion (µg/L):** 1,800 _(verified: appears in the quote below)_

## What the source says

> Isophorone (P) | 78591 | 34 | 1,800 | 2015

## 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/).