
Bromophenol Red is a synthetic dye and pH indicator that responds to changes in the acidity or alkalinity of a solution. It is also known as Bromophenol Red Free Acid and has the chemical formula C₁₉H₁₂Br₂O₅S. The compound generally appears as a dark reddish-brown to reddish-red crystalline or powdered substance. Its sensitivity and stability provide a consistent color response which makes it useful in laboratory methods such as pH monitoring, titrations and selected histological staining applications.

CAS No.: 2800-80-8
Synonyms: Bromophenol Red free acid, dibromophenolsulfonephthalein, Bromphenolrot.
| Physical Properties | |
| Chemical formula | C19H12Br2O5S |
| IUPAC Name | 3′,3”-Dibromophenolsulfonphthalein |
| Molecular weight | 512.17 g/mol |
| Solubility | Sparingly soluble in water; soluble in ethanol |
| Density | 1.881g/cm3 |
| Flash Point | 308.7ºC |
| Appearance | Red powder |
| Storage | Store at room temperature |
| Chemical Properties | |
| Color | Red-brown to brown |
| Physical State | Solid |
| Melting Point | 230 °C |
| Boiling Point | 586.8ºC at 760 mmHg |
| Vapor Pressure | 2.29E-14mmHg at 25°C |
| Ph | 5.2~7.0 |
| λmax | 574 nm |
| Pictograms : | ![]() |
| Hazard Statements : | H302: Harmful if swallowed H315: Causes skin irritation H319: Causes serious eye irritation H335: May cause respiratory irritation |
| Precautionary Statements: | P305+P351+P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. P261: Avoid breathing dust/fume/gas/mist/vapours/spray. |
Bromophenol Red is a synthetic dye and pH indicator that responds to changes in the acidity or alkalinity of a solution. It is also known as Bromophenol Red Free Acid and has the chemical formula C₁₉H₁₂Br₂O₅S. The compound generally appears as a dark reddish-brown to reddish-red crystalline or powdered substance. Its sensitivity and stability provide a consistent color response which makes it useful in laboratory methods such as pH monitoring, titrations and selected histological staining applications.

CAS No.: 2800-80-8
Synonyms: Bromophenol Red free acid, dibromophenolsulfonephthalein, Bromphenolrot.
| Physical Properties | |
| Chemical formula | C19H12Br2O5S |
| IUPAC Name | 3′,3”-Dibromophenolsulfonphthalein |
| Molecular weight | 512.17 g/mol |
| Solubility | Sparingly soluble in water; soluble in ethanol |
| Density | 1.881g/cm3 |
| Flash Point | 308.7ºC |
| Appearance | Red powder |
| Storage | Store at room temperature |
| Chemical Properties | |
| Color | Red-brown to brown |
| Physical State | Solid |
| Melting Point | 230 °C |
| Boiling Point | 586.8ºC at 760 mmHg |
| Vapor Pressure | 2.29E-14mmHg at 25°C |
| Ph | 5.2~7.0 |
| λmax | 574 nm |
| Pictograms : | ![]() |
| Hazard Statements : | H302: Harmful if swallowed H315: Causes skin irritation H319: Causes serious eye irritation H335: May cause respiratory irritation |
| Precautionary Statements: | P305+P351+P338: IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continue rinsing. P261: Avoid breathing dust/fume/gas/mist/vapours/spray. |
Bromophenol Red is mainly used as a pH indicator in laboratory applications. It is used as a fermentation indicator in bacterial culture media to detect pH changes resulting from carbohydrate fermentation in microbiology.
Bromophenol Red and Bromophenol Blue both belong to the phenolsulfonphthalein family. But they are different chemical indicators with different structures and pH transition characteristics.