2-BUTOXYETHANOL PHOSPHATE

2-butoxyethanol phosphate is a trialkyl organophosphate ester commonly identified as tris(2-butoxyethyl) phosphate.
2-butoxyethanol phosphate functions as a plasticizer, leveling aid, viscosity modifier, antifoaming agent, solvent, and additive flame retardant.
2-butoxyethanol phosphate is used in floor-care formulations, polymers, synthetic rubber, coatings, lacquers, adhesives, inks, and specialty industrial systems.

CAS Number: 78-51-3
EC Number: 201-122-9
Molecular Formula: C₁₈H₃₉O₇P
Molecular Weight: 398.47 g/mol

SYNONYMS

2-butoxyethanol phosphate, Tris(2-butoxyethyl) Phosphate, Tris(2-Butoxyethyl) Phosphate, Tri(2-butoxyethyl) Phosphate, Tri-2-Butoxyethyl Phosphate, Trisbutoxyethyl Phosphate, Tributoxyethyl Phosphate, Tributoxyethylphosphate, Tri(butoxyethyl) Phosphate, Tris(butoxyethyl) Phosphate, Tris(2-n-butoxyethyl) Phosphate, Tris[2-(butyloxy)ethyl] Phosphate, Phosphoric Acid Tris(2-butoxyethyl) Ester, Phosphoric Acid Tri(2-butoxyethyl) Ester, Phosphoric Acid Tributoxyethyl Ester, Phosphoric Acid Tri(butoxyethyl) Ester, Ethanol, 2-Butoxy-, Phosphate (3:1), Ethanol 2-Butoxy Phosphate 3:1, Ethanol, 2-Butoxy-, 1,1′,1″-Phosphate, 2-Butoxyethanol Phosphate 3:1, Tri(2-butoxyethanol) Phosphate, Tris(2-butoxyethanol) Phosphate, Tributyl Cellosolve Phosphate, Tris(Butyl Glycol) Phosphate, Butyl Glycol Phosphate Triester, 2-Butoxyethyl Phosphate Triester, Butoxyethyl Phosphoric Acid Triester, 2-Butoxyethanol Phosphoric Acid Triester, TBOEP, TBEP, TBEPh, Trialkyl Phosphate Ester, Alkoxyalkyl Phosphate Ester, Butoxyethyl Organophosphate, Nonhalogenated Organophosphate Ester, Phosphate Ester Plasticizer, Butoxyethyl Phosphate Plasticizer, Organophosphate Plasticizer, Phosphorus-Containing Plasticizer, Additive Flame-Retardant Phosphate Ester, Floor-Polish Phosphate Ester, Floor-Finish Plasticizer, Plastisol Viscosity Modifier, Synthetic-Rubber Plasticizer, Lacquer Plasticizer, Resin Solvent Additive, Coating Leveling Additive, CAS 78-51-3, EC 201-122-9, EINECS 201-122-9, PubChem CID 6540, UNII RYA6940G86, C₁₈H₃₉O₇P

APPLICATIONS

2-butoxyethanol phosphate serves as a plasticizing and leveling component in compatible floor-polish formulations.
2-butoxyethanol phosphate helps the applied floor finish spread into a smoother and more uniform film before drying.

2-butoxyethanol phosphate supports resilient floor-care finishes requiring flexibility and reduced brittleness.
2-butoxyethanol phosphate can improve film formation when polymer chemistry, wax content, surfactants, and drying conditions are properly balanced.

2-butoxyethanol phosphate functions as a wetting and flow-supporting additive in selected aqueous and solvent-containing floor finishes.
2-butoxyethanol phosphate must be evaluated for effects on gloss, slip, soil pickup, recoating, buffing, and long-term film durability.

2-butoxyethanol phosphate contributes antifoaming activity to compatible floor-polish and industrial formulation systems.
2-butoxyethanol phosphate can reduce persistent air incorporation when dosage, mixing intensity, surfactant structure, and formulation polarity are suitable.

2-butoxyethanol phosphate functions as a viscosity modifier in plastisol formulations.
2-butoxyethanol phosphate can alter processing viscosity, flow, fusion behavior, flexibility, and additive compatibility in vinyl plastisols.

2-butoxyethanol phosphate serves as a plasticizer in compatible vinyl-resin systems.
2-butoxyethanol phosphate helps reduce intermolecular restriction within the polymer and can improve softness, flexibility, and processability.

2-butoxyethanol phosphate supports plasticized polyvinyl chloride formulations requiring a liquid phosphate ester.
2-butoxyethanol phosphate must be evaluated for migration, extraction, permanence, thermal stability, electrical behavior, and aging.

2-butoxyethanol phosphate contributes to flexible floor-covering formulations containing compatible vinyl polymers.
2-butoxyethanol phosphate can provide both plasticizing and phosphorus-containing additive functions when the complete flooring system is properly designed.

2-butoxyethanol phosphate functions as a plasticizer in selected synthetic-rubber compounds.
2-butoxyethanol phosphate can improve compound softness, processing behavior, low-temperature flexibility, and filler incorporation.

2-butoxyethanol phosphate supports nitrile-rubber formulations requiring compatibility with polar elastomer structures.
2-butoxyethanol phosphate performance depends on acrylonitrile content, filler system, cure package, extraction conditions, and intended service environment.

2-butoxyethanol phosphate contributes to rubber closures, seals, gaskets, and molded elastomer components after application-specific assessment.
2-butoxyethanol phosphate must meet relevant migration, extractables, purity, and contact-material requirements for sensitive applications.

2-butoxyethanol phosphate functions as a plasticizer in cellulose-acetate and related cellulosic polymer systems.
2-butoxyethanol phosphate can modify flexibility, processing temperature, film formation, and resistance to cracking.

2-butoxyethanol phosphate supports nitrocellulose lacquers requiring plasticization and improved film flexibility.
2-butoxyethanol phosphate can reduce brittle film behavior while influencing drying, gloss, adhesion, hardness, and solvent release.

2-butoxyethanol phosphate contributes to industrial paints and coatings as a plasticizer, flow modifier, or formulation solvent.
2-butoxyethanol phosphate must be assessed for resin compatibility, pigment wetting, drying, adhesion, chemical resistance, and film appearance.

2-butoxyethanol phosphate functions in rust-protective paint formulations when compatible with the selected binder and corrosion-control pigment package.
2-butoxyethanol phosphate can support film flexibility and application behavior but does not independently provide complete corrosion protection.

2-butoxyethanol phosphate supports lacquer and varnish formulations requiring a high-boiling liquid additive.
2-butoxyethanol phosphate can reduce rapid film embrittlement while affecting hardness development, blocking, and solvent retention.

2-butoxyethanol phosphate serves as a solvent or solvating additive for selected resin systems.
2-butoxyethanol phosphate low volatility allows extended formulation residence compared with rapidly evaporating process solvents.

2-butoxyethanol phosphate contributes to adhesives and sealants requiring flexibility, flow adjustment, or phosphate-ester plasticization.
2-butoxyethanol phosphate suitability depends on bond strength, creep resistance, migration, curing mechanism, substrate compatibility, and service temperature.

2-butoxyethanol phosphate can be used in limited food-packaging adhesive layers only where the exact composition and indirect-contact application are authorized.
2-butoxyethanol phosphate must not be assumed suitable for direct food contact without jurisdiction-specific regulatory confirmation.

2-butoxyethanol phosphate functions in printing inks and marker formulations requiring flow, plasticization, or controlled drying.
2-butoxyethanol phosphate can influence rub resistance, adhesion, flexibility, gloss, blocking, and compatibility with the printing substrate.

2-butoxyethanol phosphate has been identified in glass-marker and specialty marking formulations.
2-butoxyethanol phosphate should be assessed for migration, odor, drying, pigment dispersion, and user-exposure conditions.

2-butoxyethanol phosphate can be evaluated in leather-repair solutions and specialty leather finishes.
2-butoxyethanol phosphate may modify film flexibility and application flow when compatible with the resin, pigment, and leather surface.

2-butoxyethanol phosphate can be incorporated into specialized waterproofing and protective spray formulations where legally permitted.
2-butoxyethanol phosphate aerosol applications require strict inhalation-exposure assessment, ventilation, and validation of substrate performance.

2-butoxyethanol phosphate functions as an additive flame retardant in selected plastics, rubber, coatings, and polymeric materials.
2-butoxyethanol phosphate flame-retardant performance must be demonstrated in the complete material through the applicable flammability test.

2-butoxyethanol phosphate supports laboratory formulation, compatibility, migration, environmental-monitoring, and materials-research programs.
2-butoxyethanol phosphate can be analyzed through gas chromatography, mass spectrometry, infrared spectroscopy, and nuclear magnetic resonance methods.

DESCRIPTION

2-butoxyethanol phosphate is commonly used as a commercial and registry synonym for tris(2-butoxyethyl) phosphate.
2-butoxyethanol phosphate in this context is the 3:1 ester of 2-butoxyethanol and phosphoric acid rather than mono(2-butoxyethyl) phosphate.

2-butoxyethanol phosphate has the molecular formula C₁₈H₃₉O₇P and a molecular weight of approximately 398.47 g/mol.
2-butoxyethanol phosphate is identified by CAS Number 78-51-3 and EC Number 201-122-9.

2-butoxyethanol phosphate contains one phosphoryl group and three 2-butoxyethyl ester groups.
2-butoxyethanol phosphate combines a polar phosphate center with three ether-containing hydrophobic substituents.

2-butoxyethanol phosphate is classified structurally as a nonhalogenated trialkyl organophosphate ester.
2-butoxyethanol phosphate does not contain the chlorine or bromine atoms present in halogenated organophosphate flame retardants.

2-butoxyethanol phosphate normally appears as a clear to slightly yellow oily or viscous liquid with a mild sweetish or butyl-like odor.
2-butoxyethanol phosphate remains liquid at low temperatures because its melting point is reported near −70°C.

2-butoxyethanol phosphate has a density of approximately 1.02 g/mL and a viscosity of approximately 11–15 mPa·s at 20°C.
2-butoxyethanol phosphate has a refractive index reported near 1.434 at 25°C.

2-butoxyethanol phosphate has very low vapor pressure at ordinary room temperature.
2-butoxyethanol phosphate nevertheless can generate mist during spraying and vapors or decomposition products during excessive heating.

2-butoxyethanol phosphate has water solubility commonly reported near 1.1–1.3 g/L at 20°C.
2-butoxyethanol phosphate displays greater compatibility with many organic and nonpolar media than with water.

2-butoxyethanol phosphate has a reported flash point near 210°C and is combustible when sufficiently heated.
2-butoxyethanol phosphate can release carbon oxides and phosphorus oxides during fire or thermal decomposition.

2-butoxyethanol phosphate can be manufactured by reacting phosphorus oxychloride with 2-butoxyethanol under controlled conditions.
2-butoxyethanol phosphate technical material can contain small quantities of related phosphate esters, residual alcohol, or phosphoric-acid-derived impurities.

2-butoxyethanol phosphate plasticizes polymers by increasing molecular mobility and reducing the rigidity of the polymer matrix.
2-butoxyethanol phosphate remains an additive rather than becoming permanently covalently bound in most conventional plasticized systems.

2-butoxyethanol phosphate can migrate, leach, or transfer from polymeric materials depending on concentration, polymer compatibility, temperature, and contact medium.
2-butoxyethanol phosphate migration and exposure must therefore be assessed for long-term, indoor, contact-material, and sensitive-use applications.

2-butoxyethanol phosphate is stable under recommended storage conditions but can react with strong oxidizing materials.
2-butoxyethanol phosphate should be protected from excessive heat, strong oxidizers, strong reducing agents, and incompatible reactive chemicals.

2-butoxyethanol phosphate hazard classifications vary between regulatory notifications and product specifications.
2-butoxyethanol phosphate has been reported by some notifications as capable of causing respiratory irritation, drowsiness, or dizziness, while many other notifications do not assign these classifications.

2-butoxyethanol phosphate is currently included in an ongoing Canadian assessment process rather than a finalized 2026 conclusion.
2-butoxyethanol phosphate has a final Canadian assessment anticipated for November 2026, while the November 2025 document proposed that current exposure may present human-health concerns.

PROPERTIES

Chemical Name: Tris(2-butoxyethyl) Phosphate

Chemical Class: Trialkyl Organophosphate Ester

CAS Number: 78-51-3

EC Number: 201-122-9

Molecular Formula: C₁₈H₃₉O₇P

Molecular Weight: 398.47 g/mol

Physical Form: Oily Liquid

Appearance: Clear to Slightly Yellow

Odor: Mild Sweetish or Butyl-Like Odor

Melting Point: Approximately −70°C

Density at 20°C: Approximately 1.02 g/mL

Viscosity at 20°C: Approximately 11–15 mPa·s

Water Solubility at 20°C: Approximately 1.1–1.3 g/L

Flash Point: Approximately 210°C

Primary Functions: Plasticizer, Leveling Aid, Viscosity Modifier, Antifoam, Solvent, and Additive Flame Retardant

Main Uses: Floor Finishes, Polymers, Rubber, Coatings, Lacquers, Adhesives, and Inks

Storage: Cool, Dry, Tightly Closed, and Protected from Heat and Oxidizing Agents

FIRST AID

Inhalation

Move the person exposed to 2-butoxyethanol phosphate mist, vapor, aerosol, or decomposition fumes into fresh air and allow comfortable breathing.
Obtain medical attention if 2-butoxyethanol phosphate exposure causes coughing, respiratory irritation, headache, dizziness, drowsiness, or breathing difficulty.

Skin Contact

Remove clothing contaminated with 2-butoxyethanol phosphate and wash the affected skin thoroughly with soap and water.
Obtain medical attention if 2-butoxyethanol phosphate causes persistent redness, irritation, pain, dryness, or other adverse skin effects.

Eye Contact

Immediately rinse eyes exposed to 2-butoxyethanol phosphate with clean running water for at least 15 minutes while holding the eyelids open.
Remove contact lenses when easy to do and obtain medical attention if 2-butoxyethanol phosphate irritation, pain, redness, or visual disturbance persists.

Ingestion

Rinse the mouth after accidental ingestion of 2-butoxyethanol phosphate and do not induce vomiting unless instructed by medical personnel.
Contact a physician or poison information center after significant 2-butoxyethanol phosphate ingestion or whenever symptoms develop.

Note to Physicians

Treat 2-butoxyethanol phosphate exposure symptomatically and provide appropriate supportive care.
Assess 2-butoxyethanol phosphate exposure according to quantity, purity, route, symptoms, aspiration potential, and the current grade-specific Safety Data Sheet.

HANDLING AND STORAGE

Handling

Handle 2-butoxyethanol phosphate according to good industrial hygiene and organophosphate-ester processing practices.
Avoid 2-butoxyethanol phosphate contact with the eyes and skin and minimize generation of mist, aerosol, or heated vapor.

Ventilation

Provide effective general ventilation and local exhaust wherever 2-butoxyethanol phosphate is transferred, sprayed, heated, sampled, or mixed.
Use suitable respiratory protection when engineering controls cannot adequately control airborne 2-butoxyethanol phosphate mist, vapor, or aerosol.

Storage

Store 2-butoxyethanol phosphate in tightly closed and chemically compatible containers within a cool, dry, and well-ventilated area.
Protect 2-butoxyethanol phosphate from excessive heat, direct sunlight, strong oxidizing agents, strong reducing agents, and contamination.

Spill and Leak Procedures

Contain spilled 2-butoxyethanol phosphate with a suitable inert absorbent while maintaining adequate ventilation.
Prevent 2-butoxyethanol phosphate from entering drains, soil, groundwater, or surface water and transfer collected waste into labeled closed containers.

Handling Precautions

Wear chemical-resistant gloves, protective clothing, and tightly fitting safety goggles while handling 2-butoxyethanol phosphate.
Review the current grade-specific Safety Data Sheet before transporting, heating, spraying, formulating, or disposing of 2-butoxyethanol phosphate.