Texanol (TMPD Monoisobutyrate) in Paint: Function, Typical Level, Grades and Regulatory Status

Texanol (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, TMPD-MIB, CAS 25265-77-4) is a slow-evaporating ester alcohol coalescent that lowers the minimum film formation temperature of latex paint so the film forms at application temperature. It boils at 254 °C (489 °F) at 101.3 kPa, 4 °C above the EU boundary for a volatile organic compound (VOC), and that one number shapes most of its regulatory profile.

The status of TMPD-MIB differs by rule: it has no harmonized CLP classification, it is not a VOC under Directive 2004/42/EC, it counts as a semi-volatile organic compound (SVOC) under the EU Ecolabel, and it is a VOC under US EPA rules. Texanol is one of the film-formation aids among the paint additives a formulator doses in small amounts.

The sections below give its identity and physical data, how it forms a latex film, the paints that use it, published levels with their basis, its trade-offs, a dated EU and US regulatory matrix, its documents, four alternatives and how to source it; in British usage it is a film-forming aid for emulsion paint.

How we check: regulations and classifications are read at the body that issues them, standards at the standards body, and every additive level names its basis and its source; the full method is in methodology and fact-checking.

The identity card below lists the attributes that define the substance.

What Is Texanol? Identity, CAS 25265-77-4 and Structure#

Texanol is Eastman's trade name for 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (TMPD-MIB), an ester alcohol with CAS 25265-77-4, EC 246-771-9 and the formula C12H24O3, sold as an isomer mixture. The molar mass is 216.32 g/mol. As a chemical, TMPD-MIB is a mixture of the UVCB type rather than a single defined molecule, because the commercial product holds more than one isomer of the monoester. One hydroxyl group and one ester group sit on the same molecule, which is why the class name reads "ester alcohol".

Texanol Chemical Name, Synonyms and Isomer Structure#

The chemical name of TMPD-MIB is 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate; the commercial product is a mixture of isomers (UVCB), the hydroxy ester of TMPD and isobutyric acid. In IUPAC style one isomer reads (3-hydroxy-2,2,4-trimethylpentyl) 2-methylpropanoate. The seven synonyms that buyers and data sheets use are listed below.

• Texanol ester alcohol
• TMPD monoisobutyrate
• TMPIB
• trimethyl hydroxypentyl isobutyrate
• (3-hydroxy-2,2,4-trimethylpentyl) 2-methylpropanoate
• isobutyric acid, monoester with 2,2,4-trimethylpentane-1,3-diol
• ester alcohol coalescent

Physical Properties: Boiling Point, Density and Flash Point#

TMPD-MIB is a clear liquid with a boiling point of 254 °C (489 °F) at 101.3 kPa (760 mm Hg). The table below gives the values of the producer's technical data sheet dated 2025-03-20.

PubChem and the International Chemical Safety Card print a boiling point of 255 to 260 °C, and every one of these values sits above the 250 °C (482 °F) line of the EU Decopaint Directive.

How Does Texanol Work as a Coalescing Agent in Latex Paint?#

Texanol works by partitioning into the latex particles, where it temporarily plasticizes the polymer and lowers its glass transition temperature (Tg) and MFFT, so the particles deform and fuse into a continuous film at application temperature. TMPD-MIB is hydrophobic, so it partitions into the latex particles. Particle deformation and interdiffusion of polymer chains then take place at a temperature the binder alone could not reach. After the film has formed, the coalescent evaporates slowly, and film hardness and block resistance recover.

The function of Texanol in paint production is to let a latex binder whose MFFT lies above the application temperature form a continuous film by lowering its Tg and MFFT for the drying period. Perera, Vanden Eynde and Borsus (Journal of Coatings Technology, 2001) describe MFFT as directly related to Tg, with a higher coalescent level giving a lower Tg.

Coalescing agents for latex paint work the same way as a class, and patent US20210009844A1 states the cost: lowering Tg also lowers hardness. How the whole class works, from glycol ethers to non-volatile esters, is compared on coalescing agents for latex paint.

Why Texanol's Slow Evaporation Restores Film Hardness#

TMPD-MIB leaves the film slowly because its vapor pressure is 1.3 Pa at 20 °C and its evaporation rate is 0.002 against n-butyl acetate at 1, so film hardness recovers after film formation. Slow loss keeps the coalescent in the polymer while the particles fuse.

DPnB, a P-series glycol ether, evaporates faster, with a vapor pressure of 6 Pa at 20 °C, about 4.6 times that of TMPD-MIB.

Which Paint Types Use Texanol?#

Texanol is used in waterborne latex (emulsion) paints, interior and exterior, of all latex types and over substrates of different porosity. The two published paint studies on record are listed below.

• Acrylic latex paint at a pigment volume concentration (PVC) of 45 %, studied on glass and fiber cement in a 2001 journal paper
• Interior semi-gloss emulsion paint at 50 g/L VOC, studied in a published comparison of low-VOC coalescents

Interior and Exterior Emulsion Paints#

For exterior emulsion paint, the producer's data sheet states that TMPD-MIB performs in all latex types, interior and exterior; the 2001 study of an acrylic latex paint on fiber cement is covered in the next section. For interior paint, a BASF study uses TMPD-MIB as the benchmark coalescent for its ultra-low-VOC agents. In that study's 50 g/L interior semi-gloss at equal loadings on resin solids, the ultra-low-VOC agents gave higher gloss and in part better stain resistance but lower hardness, while scrub resistance was unaffected.

The full additive package of a latex paint, and where the coalescent sits in it, is shown in emulsion (latex) paint formulation.

Paints Applied over Porous Substrates such as Fiber Cement#

Porous substrates absorb part of the TMPD-MIB: Perera, Vanden Eynde and Borsus (Journal of Coatings Technology 73 (919), 2001) measured 15.4 % absorbed, 46.6 % evaporated and 37.9 % left in the film after one day on fiber cement. On glass, 53.4 % of the coalescent stayed in the film over the same day. The fiber-cement film therefore held 15.5 percentage points less coalescent than the glass film (53.4 minus 37.9). All values are percentages of the coalescent in the wet paint. The table below compares the two substrates after one day.

Texanol Dosage in Paint: Published Levels and Their Basis#

Texanol has no single class-wide level: one published acrylic latex paint at 45 % PVC carries 5.06 % on dry paint weight, and patent US8106239B2 puts coalescents in general at 0.1 to 10 % on total formula (wet). That value is the level of one paint in the 2001 study by Perera, Vanden Eynde and Borsus, and its basis is the dry paint weight, not the wet paint. The patent range is a background statement about coalescents as a class, so it is never a norm for TMPD-MIB alone. The same gram of coalescent is a larger percentage of the dry paint than of the wet paint, so the two bases are not interchangeable. The table below lists both published values with their basis.

How Labs Dose Texanol to Reach a Target MFFT#

Labs set the coalescent level by measuring the MFFT of the latex at each dose. ASTM D2354-10(2023) is the standard MFFT test, limited to MFFT below 90 °C (194 °F). The BASF study on low-VOC coalescents prepares each dose as follows (steps 1 and 2); patent US20210009844A1 reads the MFFT on a gradient bar (steps 3 and 4).

1. Mix 90 g of latex with the coalescent dose and make the sample up to 100 g with water.
2. Stir for 5 min at low shear and let the sample rest overnight at 50 % relative humidity and 21.1 °C (70 °F).
3. Draw down a 76.2 µm (3 mil) film on a gradient bar spanning -5 to 15 °C (23 to 59 °F) (US20210009844A1).
4. Read the MFFT as the lowest temperature that gives a clear, crack-free film (US20210009844A1).

The test, the Tg link and worked examples are on minimum film formation temperature (MFFT).

Texanol Trade-Offs: Hardness, Gloss, VOC and Interactions#

In a BASF study of a 50 g/L interior semi-gloss at equal loading on resin solids, Texanol gave harder films but lower gloss than the ultra-low-VOC coalescents tested, and in the US it adds to the VOC content of the paint. The four trade-offs that decide whether TMPD-MIB fits a paint are listed below.

• Hardness and block resistance versus gloss: block resistance recovers only as the coalescent leaves the film, which ties a slow coalescent to blocking in paint films, and lower Tg also lowers hardness (US20210009844A1).
• Substrate loss: a porous board such as fiber cement absorbs part of the coalescent, so its film keeps less of it than a film on glass (Perera, Vanden Eynde and Borsus, 2001).
• VOC contribution in US rules: TMPD-MIB is not exempt under 40 CFR 51.100(s), so every gram counts toward the federal AIM limits and the SCAQMD Rule 1113 limits.
• Thickener interaction: the producer's data sheet claims higher thickening efficiency with associative thickeners, such as HEUR types.

Glycol is present at 2 to 3 times the coalescent amount in a latex paint (Mitchell, PCI, 2005), so a switch away from TMPD-MIB alone cuts only part of the VOC. Non-fugitive coalescents cut VOC but need checks of dirt pick-up and block resistance (Mitchell, PCI, 2005).

Regulatory Status of Texanol: CLP, REACH, TSCA and VOC#

Texanol has no harmonized CLP classification, is REACH-registered, is on no REACH authorization or restriction list, is on the US TSCA Inventory and is a US VOC but not an EU Decopaint VOC (status 2026-11-03). The matrix below gives instrument, entry, status, source and date for each rule.

EU Classification and REACH Status of Texanol#

TMPD-MIB has no Annex VI entry; 98.78 % of ECHA C&L notifications, those of the REACH joint submission updated 2026-08-17, report it as not classified. The hazard line is therefore the notified one shown in the matrix above, with no index number and no ATP because no harmonized entry exists. Four other classifications are also notified by a minority (0.17 to 0.52 % each): Eye Irrit. 2 H319, Aquatic Chronic 3 H412, STOT SE 3 H335 and Skin Irrit. 2 H315. Under the registrants' classification, TMPD-MIB triggers no classification of a paint that contains it. Under REACH the substance is registered (ECHA CHEM, read 2026-11-03), it is not on the Candidate List of substances of very high concern, it is not listed in Annex XIV and it has no Annex XVII restriction entry.

Is Texanol a VOC? EU, Ecolabel, US Federal and SCAQMD Status#

No in the EU under Directive 2004/42/EC, yes in the US: TMPD-MIB boils at 254 °C, above the EU limit of 250 °C, but 40 CFR 51.100(s) does not exempt it. The table below sets out the status under each instrument.

The two EU instruments read the same boiling point in different ways. As a worked example, a waterborne paint in Decopaint category (a), "interior matt walls and ceilings", must stay at or below 30 g/L (0.25 lb/gal) ready to use under the Phase II limits in force since 2010-01-01; TMPD-MIB adds nothing to that figure, while DPnB, which boils below 250 °C, counts in full. Why one molecule can be a VOC in one market and not in another is explained on VOC in paint.

The US reference method is EPA Method 24, and its result governs over formulation data under 40 CFR 59.406(b). Patent US8106239B2 reports TMPD-MIB as about 99.8 % volatile by Method 24 (99.81 % in its test tables), so nearly every gram added counts toward the federal limits for flat paint (250 g/L) and nonflat paint (380 g/L).

US TSCA Inventory and Clean Air Act HAP Status#

TMPD-MIB is on the TSCA Inventory, listed by EPA's Substance Registry Services as "2024 CDR TSCA Inventory active" (read 2026-11-03); it is not a hazardous air pollutant (HAP) because it falls outside the Clean Air Act glycol-ethers category. That category in 40 CFR 63.62 covers only mono- and di-ethers of ethylene, diethylene and triethylene glycol, so P-series glycol ethers such as DPnB and PPh fall outside it as well.

Texanol Safety and Handling: SDS, TDS and Labeling#

Texanol carries no hazard classification under the registrants' CLP notification, so it triggers no hazard labeling of the paint by itself, and its handling data come from the supplier's safety data sheet (SDS). The flash point is 120 °C (248 °F) by Cleveland open cup. The TDS of Texanol is its technical data sheet, and the producer's product page links it together with the SDS and the sales specification. The three documents a buyer receives are listed below.

• Safety data sheet (SDS): classification, handling, storage and transport data
• Technical data sheet (TDS): physical properties such as boiling point, vapor pressure and assay
• Sales specification: the guaranteed limits that a delivery meets, such as the minimum assay

CLP labeling of paints depends on the ingredients that carry a classification, such as sensitizing in-can preservatives, and TMPD-MIB is not one of them under the registrants' classification. Which ingredients do trigger a paint label is set out on CLP labeling of paints.

Alternatives to Texanol: DPnB, TXIB, Benzoates and Low-VOC Options#

The four alternatives compared here are DPnB and PPh, which boil below 250 °C and count as VOCs in the EU, TXIB, which like TMPD-MIB boils above 250 °C, and 2-ethylhexyl benzoate, which registrants notify as Repr. 1B H360. The table below compares each with TMPD-MIB on boiling point, EU VOC status and notified classification; none of the five has an Annex VI entry.

DPnB and PPh count in full toward a paint's EU VOC content because both boil below 250 °C, while TXIB, like TMPD-MIB, stays outside it but counts as an SVOC under the EU Ecolabel. The Ecolabel Decision (EU) 2025/2607 bars ingoing substances classified H360 or H361 at 0.010 % w/w or more of the final paint unless Table 7 grants a derogation, which affects TXIB and 2-EHB under their REACH joint submission classifications. A paint with 0.3 % or more 2-EHB classifies as Repr. 1B if that classification is applied (CLP Annex I Table 3.7.2).

Texanol Grades, Suppliers and How to Request a Quote#

Eastman sells one grade, "Texanol ester alcohol", whose sales specification guarantees an assay of 98.5 wt % minimum, and buyers compare offers on the TDS, SDS and sales specification of each source. Eastman publishes no prices and no minimum order quantities, so an offer depends on the grade, pack size, annual volume and delivery country that a buyer states. A request names the substance (CAS 25265-77-4), the assay, the documents needed, the annual volume in kg or lb and the delivery country.

How Texanol Compares Within the Coalescing Agent Family#

Within the coalescing agent family, Texanol belongs with the hydrophobic coalescents such as DPnB and benzoates, which partition into the latex particles, while water-miscible ones stay in the water phase (Mitchell, PCI, 2005). Mitchell names DPM, propylene glycol and butyl glycol as examples of the water-miscible group. The other members of the family are compared on the hub for coalescing agents.

Texanol FAQs#

The three questions below compare TMPD-MIB with TXIB, with zero-VOC claims and with glycols.

Is Texanol the same as TXIB?#

No: TXIB (CAS 6846-50-0), also sold as "Texanol isobutyrate", is the diisobutyrate diester of TMPD, while TMPD-MIB is the monoester. The diester, TXIB (TMPD diisobutyrate), is a different substance with a boiling point of 281 °C.

Is Texanol zero VOC?#

Not everywhere: TMPD-MIB is not a VOC under Directive 2004/42/EC, it counts as an SVOC under EU Ecolabel Decision (EU) 2025/2607, and it is a VOC under 40 CFR 51.100(s) in the US. A "zero VOC" claim for it needs a named jurisdiction.

Does Texanol replace glycol in a latex paint?#

No: glycols such as ethylene and propylene glycol stay in the water phase and serve freeze-thaw stability and open time, while TMPD-MIB partitions into the latex particles to lower MFFT (Mitchell, PCI, 2005).

Glycols serve as freeze-thaw stabilizers for latex paint and open-time aids.