Tricresyl Phosphate

1. Product Overview

Tricresyl phosphate (TCP) is an organophosphate compound widely recognized as a multifunctional industrial chemical serving primarily as a flame retardant plasticizer and extreme pressure additive. It consists of a phosphate group esterified with three cresyl (methylphenyl) groups, typically existing as a mixture of ortho, meta, and para isomers .

The chemical formula is C₂₁H₂₁O₄P with CAS number 1330-78-5 (mixed isomers) and molecular weight of 368.36 g/mol . The product appears as a colorless to pale yellow clear liquid with minimal odor .

TCP occupies a unique position in industrial chemistry, combining the properties of a plasticizer with inherent flame-retardant functionality. Its ability to impart flexibility, flame resistance, and lubricity makes it indispensable across multiple industries—from PVC processing and engineering plastics to hydraulic fluids and extreme pressure lubricants .

Commercial TCP is typically produced as a mixed isomer product, with careful control of the highly toxic ortho isomer content to ensure safety in industrial applications .

2. Key Features

• Dual Functionality – Plasticizer & Flame Retardant: TCP uniquely combines plasticizing properties with inherent flame-retardant activity, reducing the need for multiple additives in polymer formulations . The phosphorus content (typically 8.4% ) provides effective flame retardancy .

• Excellent Compatibility: Exhibits outstanding compatibility with a wide range of polymers including PVC, epoxy resins, phenol resins, polyurethane, polystyrene, and various engineering plastics . It improves processability and aging resistance of finished products .

• Superior Electrical Insulation: Provides excellent electrical insulation properties with volume resistivity of min. 5×10⁹ ohm-cm at 30°C, making it ideal for cable and wire applications .

• Exceptional Extreme Pressure Performance: Demonstrates very high performance under extreme pressure conditions, making it valuable as an additive in lubricant oils .

• Mildew and Abrasion Resistance: Imparts mildew resistance and improved abrasion resistance to finished products, extending service life in demanding applications .

• Excellent Hydrolytic Stability: Shows outstanding stability against hydrolysis, ensuring consistent performance in various environmental conditions .

• Good Thermal Stability: With a flash point of 240-257°C and boiling point range of 241-255°C (at reduced pressure), TCP maintains stability under high-temperature processing conditions .

• Low Viscosity: Moderate viscosity (58-62 mPa·s at 25°C) facilitates easy handling and incorporation into formulations .

3. Technical Specifications with Explanations

Based on multiple supplier data and authoritative sources:

4. Applications

Polymer & Plastics Industry

• PVC Plasticizer with Flame Retardancy: TCP serves as a primary plasticizer for polyvinyl chloride (PVC), particularly in applications requiring flame retardant properties. It imparts heat resistance and electrical insulation to PVC compounds . Widely used in:

• Agricultural PVC films: Provides flexibility and weather resistance 

• Cable and wire insulation: Excellent electrical properties and flame retardancy 

• PVC compounds and masterbatch: General-purpose plasticization 

• Engineering Plastics: Compatible with various engineering plastics including phenol resins, epoxy resins, polyurethane, and polystyrene, improving processability and flame resistance .

• Polyurethane Applications: Used in polyurethane coatings and foams as a flame retardant additive .

• Rubber Formulations: Recommended for synthetic rubber, butylated rubber, and chloroprene rubber, imparting flame retardancy and improving processing characteristics .

• Cellulosic Materials: Acts as a solvent for nitrocellulose and additive in cellulosic molding compositions .

Lubricants & Hydraulic Fluids

• Extreme Pressure Lubricant Additive: Provides exceptional performance under extreme pressure conditions, enhancing load-bearing capacity of lubricating oils .

• Fire-Resistant Hydraulic Fluids: Used in the manufacture of fire-resistant hydraulic fluids for industrial applications where fire safety is critical .

• Gasoline Additive: Historically used as a lead scavenger in leaded gasoline .

Coatings & Adhesives

• Plasticizer for Coatings: Functions as a plasticizer and coalescing agent in lacquers and industrial coatings .

• Adhesive Applications: Used as a plasticizer in adhesives, improving flexibility and adhesion .

Analytical Chemistry

• Gas Chromatography Stationary Phase: Serves as a stationary phase for gas chromatography (maximum use temperature 125°C, solvent: ether), particularly effective for separation of aromatic hydrocarbons, phenol isomers, halogenated compounds, and mercaptans .

• Analytical Reagent: Used as an analytical reagent in various chemical testing applications .

Other Industrial Applications

• Heat Exchange Medium: Employed as a heat-exchange medium in specialized industrial processes .

• Air Filter Medium: Used in air filtration applications .

• Surgical Instrument Sterilizer: Functions as a sterilizing agent for surgical instruments .

• Cosmetic Emulsifier: Serves as an emulsifier in cosmetic formulations .

• Waterproofing Agent: Used in extreme pressure lubricants to provide waterproofing properties .

5. Product Grade Comparison

6. Purchasing & Selection Guide

Select by Application Area

1. PVC & Polymer Processors:

• Choose Industrial Grade with verified acid value (<0.05 mg KOH/g) and moisture content (<0.10%)

• For electrical applications, ensure volume resistivity meets requirements (≥5×10⁹ ohm-cm)

• Verify compatibility with your specific polymer system

• Select grades with appropriate viscosity and extreme pressure performance

• For fire-resistant fluids, confirm phosphorus content (typically 8.4%)

• Consider low ortho isomer grades for applications with potential human contact

• Must select Analytical Grade with documented purity (≥99% GC)

• For GC applications, verify suitability as stationary phase

• Request Certificate of Analysis with batch-specific data

• Specify Low Ortho Isomer Grade (ortho isomer content <1%)

• Commercial TCP is typically a mixed isomer product with the highly toxic ortho isomer carefully controlled or excluded 

Critical Selection Considerations

• Isomer Composition: The ortho isomer of TCP is highly neurotoxic. Ensure your supplier provides information on isomer distribution and confirms control of toxic isomers.

• Phenol Content: Low phenol content (<500 ppm) indicates higher purity and better safety profile .

• Acid Value: Low acid value (<0.05 mg KOH/g) ensures hydrolytic stability and prevents degradation during processing .

• Storage Requirements: Store in tightly sealed containers in cool, dry areas away from strong oxidizing agents and sources of ignition . Protect from moisture and alkaline conditions .

Regulatory & Safety Considerations

⚠️ Important Safety Notes:

• Toxicity: The ortho isomer of TCP is highly neurotoxic and caused thousands of cases of paralysis (Ginger Jake paralysis) during Prohibition-era USA when adulterated ginger extracts contained TCP. Commercial TCP products strictly control ortho isomer content to safe levels.

• Hazard Classification: TCP is classified as a hazardous material for transport:

• UN 2574

• Hazard Class: 6.1 (Poison)

• Packing Group: II 

• GHS Classification: Signal word "Warning" with appropriate hazard statements 

• Environmental Precautions: High log P (5.11) indicates bioaccumulation potential; avoid release to the environment 

• Handling: Use appropriate personal protective equipment; ensure adequate ventilation

7. Frequently Asked Questions (FAQ)

Q: What is the difference between various tricresyl phosphate isomers?

A: TCP exists as ortho, meta, and para isomers based on the position of the methyl group on the phenyl ring. The ortho isomer is highly neurotoxic and caused historical poisoning incidents. Commercial TCP is typically a mixture of meta and para isomers with ortho isomer content strictly controlled (<1%). When purchasing TCP, always verify isomer composition with your supplier.

Q: Why is TCP used as a flame retardant plasticizer?

A: TCP uniquely combines plasticizing properties with inherent flame retardancy due to its phosphorus content (8.4%). The phosphorus acts in the vapor phase to scavenge free radicals during combustion, while the cresyl groups provide plasticization similar to other aromatic esters .

Q: Is TCP soluble in water?

A: No, TCP has extremely low water solubility—approximately 0.36 mg/L at 25°C . It is, however, miscible with common organic solvents, vegetable oils, and compatible with most polymer systems .

Q: How should TCP be stored?

A: Store in tightly sealed containers in a cool, dry, well-ventilated area away from strong oxidizing agents and sources of ignition . Protect from moisture and alkaline conditions, as TCP hydrolyzes slowly under alkaline environments . Avoid storage near incompatible materials.

Q: What is the flash point of TCP, and is it flammable?

A: TCP has a high flash point of 240-257°C . While not easily ignitable under normal conditions, it will burn at elevated temperatures. It should be kept away from open flames and high heat sources.

Q: Can TCP be used in food contact applications?

A: No, TCP is not intended for food contact applications. Commercial suppliers explicitly state their products are for industrial use only and not for food or consumer products unless explicitly stated otherwise .

Q: What is the significance of acid value in TCP specifications?

A: Acid value measures free acid content from hydrolysis or degradation. Low acid value (max. 0.05 mg KOH/g) ensures hydrolytic stability and prevents corrosion or unwanted reactions during polymer processing .

Q: How does TCP perform in electrical applications?

A: TCP provides excellent electrical insulation properties with volume resistivity of min. 5×10⁹ ohm-cm at 30°C, making it ideal for cable compounds and electrical insulation applications .

Q: What documentation should I request when purchasing TCP?

A: Request:

• Certificate of Analysis (COA) with batch-specific data

• Safety Data Sheet (SDS/MSDS)

• Technical Data Sheet (TDS)

• Isomer distribution information

• Certificate of Origin (COO)

8. Delivery, Certification & Service

Delivery Capabilities

• Inventory Status: Multiple grades available from regional warehouses (Asia, Europe, Americas)

• Sample Program: Small quantities available for qualified customers for formulation testing and evaluation

• Packaging Options:

• Research quantities: Various bottle sizes

• Industrial quantities: 220 kg drums (standard) 

• Bulk quantities: ISO tanks, bulk tankers

• Special Handling: Hazardous material (UN 2574) requiring specialized transport and documentation 

• Shipping: Classified as hazardous material (Class 6.1, PG II); requires dangerous goods shipping documentation

Quality Certifications

• Certificate of Analysis (COA) provided with each batch for qualified grades, documenting:

• Appearance and color (APHA)

• Purity/assay

• Acid value

• Density and viscosity

• Moisture content

• Phosphorus content

• Phenol content (where applicable)

• Safety Data Sheet (SDS) available in multiple languages

• Product Specification (PS) documenting chemical and physical properties

• Certificates of Origin (COO) available upon request

• Additional certifications available:

• ISO 9001 quality management certification

• REACH compliance documentation (EU)

• TSCA statement (US)

Regulatory Compliance

• EU: REACH registered; CLP classification applies

• US: TSCA listed

• Transport: UN 2574, Class 6.1, Packing Group II 

• Export Documentation: Full compliance package for international shipping, including dangerous goods declarations

Technical Support & Services

• Technical Consultation: Application specialists available for:

• Grade selection guidance

• Formulation development support

• Troubleshooting processing issues

• Regulatory compliance questions

• Custom Services: Tailored specifications and packaging options for qualified customers

• Regulatory Support: Documentation for global compliance and product registration

Documentation Available

• Certificate of Analysis (COA) with batch-specific data

• Safety Data Sheet (SDS/MSDS)

• Technical Data Sheet (TDS)

• Product Specification (PS)

• Certificate of Origin (COO)

• REACH/TSCA compliance statements

• Dangerous goods shipping documentation

• ISO certifications