09054 IUPAC Gold Book - universal indicator 10.1351/goldbook.09054 09054 current 1 Visual indicator composed of a solution of several pH indicators (main components are thymol blue, methyl red, bromothymol blue and phenolphthalein) that changes color through a range of pH values, usually from 1 to 14. Universal indicators are commercially available in the form of a solution or in paper strips accompanied by a color matching chart. PAC, 2025, 97, 137. 'Glossary of terms for mass and volume in analytical chemistry (IUPAC Recommendations 2024)' on page 8 (https://doi.org/10.1515/pac-2023-0903) https://goldbook.iupac.org/terms/view/09054/html https://goldbook.iupac.org/terms/view/09054/json https://goldbook.iupac.org/terms/view/09054/plain Citation: 'universal indicator' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351/goldbook.09054 The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) for individual terms. If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org . The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using. 2026-07-23T22:41:56+00:00