Thymolphthalein
- CAS Number
- 125-20-2
- HSN Code
- 29322090
- Molecular Formula
- C28H30O4
- Catalogue Number
- AL01513
- Purity
- Min. 95%
- Molecular Weight
- 430.54 g/mol
Complies with : IP | BP | USP | EP | ACS
ISO 9001
ISO 14001
GMP
COA with every batch
Key Properties
Thymolphthalein indicator (AR, pH 9.3-10.5) is a widely used pH indicator known for its distinctive color change from colorless in acidic to blue in alkaline solutions. This compound is particularly valuable in analytical chemistry for determining pH levels in various solutions, especially in non-aqueous titrations. Its high purity grade (AR) ensures reliable and accurate results in laboratory settings. Thymolphthalein is also notable for its stability and ease of use, making it a preferred choice among chemists for precise pH measurements.
Also known as Thymol blue, Thymolphthalein indicator.
- Catalogue No.
- AL01513
- CAS Number
- 125-20-2
- Molecular Formula
- C28H30O4
- Molecular Weight
- 430.54 g/mol
- HSN Code
- 29322090
- Grade
- AR (Analytical Reagent)
- Product Form
- Substance
Thymolphthalein appears as a white to pale yellow crystalline powder. It has a melting point of approximately 260 °C, and it is soluble in organic solvents such as ethanol and acetone, but insoluble in water. The compound exhibits a strong color change at a pH range of 9.3 to 10.5, transitioning from colorless to blue. Its density is around 1.2 g/cm³, and it has a molecular weight of 430.54 g/mol, which contributes to its effectiveness as a pH indicator.
- Appearance
- White to pale yellow crystalline powder
- Shelf Life
- Stable under recommended storage conditions
- Packaging
- Available in various sizes, typically in glass or plastic containers
- Storage
- Store in a cool, dry place away from light.
1.1 — Product identifier
- Chemical Name
- Thymolphthalein
- Catalogue No.
- AL01513
- Product form
- Substance
- CAS Number
- 125-20-2
- EC Number
- 204-086-0
- Grade
- AR
- EC Index Number
- 604-005-00-4
- Chemical Formula
- C28H30O4
- HSN Code
- 29322090
- Synonyms
- Thymol blue, Thymolphthalein indicator
1.2 — Relevant identified uses of the substance or mixture and uses advised against
- Use of the substance/mixture
- pH indicator in analytical chemistry
- Uses advised against
- Not specified
1.3 — Details of the supplier of the safety data sheet
- Company identification
- Address:- 102, B wing, Savgan Heights, RTO Lane,Andheri (W), Mumbai-400 053Maharashtra, India.
1.4 — Emergency Contact Details
- Phone / e-Mail
- Phone : +91 22 26317055 Mobile : +91 9820385757 e-mail : info@alphachemika.co.in
2.3 — Other hazards
- Other hazards
- None known
3.1 — Substance
- Name
- Thymolphthalein
- CAS No.
- 125-20-2
4.1 — Description of first aid measures
- First-aid measures after inhalation
- Move to fresh air. If symptoms persist, seek medical attention.
- First-aid measures after skin contact
- Wash with soap and water. If irritation occurs, seek medical attention.
- First-aid measures after eye contact
- Rinse cautiously with water for several minutes. Remove contact lenses if present and easy to do. If irritation persists, seek medical attention.
- First-aid measures after ingestion
- Rinse mouth. Do not induce vomiting. Seek medical attention if symptoms occur.
4.2 — Most important symptoms and effects, both acute and delayed
- Symptoms relating to use
- May cause mild irritation to skin and eyes.
4.3 — Indication of any immediate medical attention and special treatment needed
- General information
- Treat symptomatically. Show this safety data sheet to the treating physician.
5.1 — Extinguishing media
- Suitable extinguishing media
- Water spray, carbon dioxide, dry chemical powder, foam.
- Unsuitable extinguishing media
- Not specified
5.2 — Special hazards arising from the substance or mixture
- Special procedures
- No special hazards identified; use standard fire-fighting procedures.
5.3 — Advice for firefighters
- Protection during firefighting
- Do not enter fire area without proper protective equipment, including respiratory protection.
6.1.1 — For non-emergency personnel
- Emergency procedures
- Contain spill and collect using appropriate methods. Dispose of in accordance with local regulations.
6.3 — Methods and material for containment and cleaning up
- Methods for cleaning up
- Use appropriate personal protective equipment. Sweep up and place in a suitable container for disposal.
6.4 — Reference to other sections
- Reference
- Not specified
7.1 — Precautions for safe handling
- Precautions for safe handling
- Avoid contact with skin and eyes. Use in a well-ventilated area.
- Hygiene measures
- Wash hands and other exposed areas with mild soap and water before eating, drinking or smoking and when leaving work.
7.2 — Conditions for safe storage, including any incompatibilities
- Storage conditions
- Store in a cool, dry place, away from incompatible materials.
8.2 — Exposure controls
- Hand protection
- Protective gloves (e.g. nitrile rubber)
- Eye protection
- Chemical safety goggles or safety glasses
- Skin and body protection
- Wear suitable protective clothing
- Respiratory protection
- Not required under normal conditions of use.
9.1 — Information on basic physical and chemical properties
- Physical state
- Solid
- Colour
- White to pale yellow
- Odour
- Odourless
- Odour threshold
- Not applicable
- pH value
- Not applicable
- Relative evaporation rate (butylacetate=1)
- Not applicable
- Melting point
- 260 °C
- Freezing point
- Not applicable
- Boiling point
- Not applicable
- Flash point
- Not applicable
- Auto-ignition temperature
- Not applicable
- Decomposition temperature
- Not applicable
- Flammability (solid, gas)
- Not flammable
- Vapour pressure
- Not applicable
- Relative vapour density at 20°C
- Not applicable
- Density
- 1.2 g/cm³
- Solubility
- Soluble in ethanol and acetone; insoluble in water
- Log Pow
- Not applicable
- Viscosity, kinematic
- Not applicable
- Viscosity, dynamic
- Not applicable
- Explosive properties
- Not explosive
- Oxidising properties
- Not oxidizing
- Explosive limits
- Not applicable
10.1 — Reactivity
- Reactivity
- Stable under normal conditions; avoid strong oxidizing agents.
10.2 — Chemical stability
- Chemical stability
- Stable under recommended storage conditions.
10.3 — Possibility of hazardous reactions
- Possibility of hazardous reactions
- No dangerous reactions known under normal conditions of use.
10.4 — Conditions to avoid
- Conditions to avoid
- Avoid contact with incompatible materials and excessive heat.
10.5 — Incompatible materials
- Incompatible materials
- Strong oxidizing agents, strong acids.
10.6 — Hazardous decomposition products
- Hazardous decomposition products
- Not specified
11.1 — Information on toxicological effects
- Acute toxicity
- Low toxicity; LD50 (oral, rat) > 5000 mg/kg.
- Skin corrosion/irritation
- May cause mild irritation.
- Serious eye damage/irritation
- May cause mild irritation.
- Respiratory or skin sensitisation
- Not a sensitizer.
- Germ cell mutagenicity
- Not classified
- Carcinogenicity
- Not classified
- Specific target organ toxicity (single exposure)
- Not classified as a specific target organ toxicant.
- Specific target organ toxicity (repeated exposure)
- Not classified
12.1 — Toxicity
- Toxicity information
- Not specified
12.2 — Persistence - degradability
- Persistence - degradability
- Not specified
12.3 — Bioaccumulative potential
- Bioaccumulative potential
- Not specified
12.4 — Mobility in soil
- Mobility in soil
- Not specified
12.6 — Other adverse effects
- Environmental precautions
- Not specified
13.1 — Waste treatment methods
- Additional Info
- Dispose of contents/container in accordance with local, regional, national and international regulations.
14.1 — UN number
- UN-No. (ADR)
- Not classified as dangerous goods.
- UN-No. (IMDG)
- Not classified as dangerous goods.
- UN-No. (IATA)
- Not classified as dangerous goods.
- UN-No. (ADN)
- Not classified as dangerous goods.
- UN-No. (RID)
- Not classified as dangerous goods.
14.2 — UN proper shipping name
- Proper Shipping Name (ADR)
- Not applicable
- Proper Shipping Name (IMDG)
- Not applicable
- Proper Shipping Name (IATA)
- Not applicable
- Proper Shipping Name (ADN)
- Not applicable
- Proper Shipping Name (RID)
- Not applicable
14.3 — Transport hazard class(es)
- Transport hazard class(es)
- Not applicable
14.4 — Packing group
- Packing group (ADR)
- Not applicable
- Packing group (IMDG)
- Not applicable
- Packing group (IATA)
- Not applicable
- Packing group (ADN)
- Not applicable
- Packing group (RID)
- Not applicable
14.5 — Environmental hazards
- Dangerous for the environment
- Not specified
- Marine pollutant
- Not specified
- Other information
- No supplementary information available
15.1 — Safety, health and environmental regulations/legislation specific for the substance or mixture
- 15.1.1 EU-Regulations
- Not specified
Thymolphthalein is primarily used as a pH indicator in strongly alkaline acid-base titrations, making it essential in various analytical chemistry applications. It is particularly useful in non-aqueous titration research, where precise pH measurement is critical. Additionally, thymolphthalein is employed in the formulation of certain pharmaceuticals and in the production of dyes and pigments. Its ability to indicate pH changes makes it valuable in educational laboratories for teaching acid-base chemistry concepts.
ISO 9001
ISO 14001
GMP
COA with every batch
- Batch Number
- AL-2026-AL01513
- Manufacturing Date
- September-2026
- Expiry Date
- September-2031
- Molecular Weight
- 430.54 g/mol
| Test | Standard | Observed |
|---|---|---|
| Description | White powder | White powder |
| pH 9.3-10.5 | Colorless to blue | Colorless to blue |
| Sensitivity | Passes test | Passes test |
The above product complies with AR grade
Technical Data Sheet
| Grade | Assay/Purity | Melting/Boiling Point | Moisture/LOD | Residue on Ignition | Related Substances | Solubility |
|---|---|---|---|---|---|---|
| AR | Min. 95% | 260 °C | Max. 0.5% | Max. 0.1% | None detected | Soluble in ethanol and acetone |
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