Structure & Key Property Notes 2-Methyl-2,4-pentanediol structure (condensed formula): (CH₃)₂C(OH)–CH₂–CH(OH)–CH₃. The C-2 tertiary hydroxyl and C-4 secondary hydroxyl groups are both available for hydrogen bonding and chemical reaction, giving MPD exceptional solvency and compatibility.  |  Why is it called hexylene glycol? MPD has six carbon atoms (hex-) and two hydroxyl groups (-ylene glycol). Hexylene glycol is its INCI (cosmetic) and common trade name, widely used in personal care ingredient listings.  |  4-Methyl-2,4-pentanediol vs 2-Methyl-2,4-pentanediol: These are positional isomers - 4-methyl-2,4-pentanediol (CAS 2004-69-5) has the methyl group at C-4 vs C-2 for MPD. They are distinct compounds with different properties; standard commercial "hexylene glycol" refers to the 2-methyl-2,4-pentanediol isomer (CAS 107-41-5).  |  R-2-methyl-2,4-pentanediol: C-4 is a stereocenter - commercial MPD is produced as the racemate (R/S mixture). The (R)-enantiomer can be resolved for specialty chiral synthesis applications.

Specification Item	Industrial Grade Coatings / Cleaning / Chemical	Cosmetic Grade Personal Care / INCI Hexylene Glycol
Appearance	Colorless transparent viscous liquid, free of visible impurities and sediment
Purity (GC)	≥ 99.5%	≥ 99.5%
Water Content	≤ 0.1%	≤ 0.05%
Color (Pt-Co)	≤ 10	≤ 5
Boiling Point	197–198 °C (1013 hPa)
Flash Point	93 °C (closed cup)
Heavy Metals	-	≤ 10 ppm
Shelf Life	12 months (sealed, 5–30°C)
Packaging	200 kg metal drum 1000 kg IBC tote	200 kg HDPE drum 1000 kg IBC tote

MPD is a high-performance cosolvent and coalescing agent in water-based coatings and latex paints. As a coalescing agent, it temporarily plasticizes latex polymer particles during film formation, reducing the minimum film-forming temperature (MFFT) and enabling continuous, crack-free films even at lower application temperatures - critical for architectural and industrial coatings applied in cool-weather conditions.

Its leveling and flow properties reduce brush marks, roller stippling, and orange-peel defects in both water-based and solvent-borne coatings. In inkjet and printing inks, MPD acts as a humectant and viscosity regulator, preventing nozzle clogging and ink drying in the printhead while maintaining dot resolution. Its high boiling point (197–198°C) minimizes evaporation loss during storage and application, reducing VOC emissions compared to faster-evaporating cosolvents.

Under its INCI name Hexylene Glycol, MPD is a widely used cosmetic ingredient listed in the EU Cosmetics Regulation (EC) No 1223/2009 and the US FDA's approved cosmetic ingredients. In skin care and hair care formulations, it performs multiple functions:

Typical use concentration: 0.5–7.5% in leave-on and rinse-off products. EU Cosmetics Regulation permits hexylene glycol use without concentration restrictions in rinse-off products; up to 3.0% in leave-on face products per safety assessment guidance. Our cosmetic-grade hexylene glycol (Pt-Co color ≤5, heavy metals ≤10 ppm) meets EU and China GB cosmetic raw material standards.

MPD is a highly effective coupling agent in water-based industrial cleaning formulations. Its dual hydrophilic/hydrophobic character bridges the incompatibility between water and oily soils, enabling surfactants to achieve deeper cleaning of grease, mineral oil, and machining residues from metal surfaces. Unlike glycol ethers, it has lower toxicity and better environmental profile while maintaining strong coupling efficiency.

In metalworking fluids (cutting oils, coolants), MPD serves as a cosolvent, biostability agent, and antifreeze additive, improving the low-temperature fluidity and freeze-point depression of water-based emulsion systems. Its high boiling point minimizes evaporation loss from open cutting fluid reservoirs, extending fluid service life and reducing top-up frequency.

MPD is an intermediate in the synthesis of plasticizers (as an esterification diol with organic acids), specialty surfactants (ether sulfonates, glucoside esters), and pesticide formulations (as cosolvent for agrochemical concentrates, improving solubility of active ingredients). In polyurethane chemistry, the branched diol structure introduces soft-segment flexibility and reduces crystallinity in polyol chains. MPD's high boiling point and water miscibility also make it a useful reaction solvent and extraction agent for aqueous reaction systems where conventional solvents phase-separate.

Property	MPD (Hexylene Glycol) CAS 107-41-5	Propylene Glycol CAS 57-55-6	Dipropylene Glycol CAS 110-98-5	1,3-Butylene Glycol CAS 107-88-0
Boiling Point	197–198 °C	188 °C	232 °C	207 °C
Flash Point	93 °C	99 °C	124 °C	121 °C
Water Miscibility	Full ✓	Full ✓	Full ✓	Full ✓
Skin Feel	Light, non-greasy ✓	Slightly heavy	Good	Good
Key Advantage	Dual solvency + coalescing + preservative boost	Low cost, GRAS status	High BP, low volatility	Cosmetic standard

⚠️ SAFETY NOTE: MPD (hexylene glycol) is a combustible liquid (flash point 93°C) and mild skin/eye irritant. GHS classification: Flammable Liquid Category 4, Skin Irritation Category 2, Eye Irritation Category 2A. It is significantly less hazardous than most industrial solvents but standard PPE is required.

Bulk pricing: Orders ≥10 MT typically unlock 8–12% discount vs small drum orders. IBC tote delivery reduces per-ton freight vs individual 200 kg drums by 5–8%. Long-term supply agreements (quarterly or annual) offer price stability linked to acetone feedstock index. Request a current MPD price quote →

Q: Is hexylene glycol the same as 2-methyl-2,4-pentanediol?

Yes - hexylene glycol is the common and INCI name for 2-methyl-2,4-pentanediol (CAS 107-41-5). In cosmetic ingredient labeling, it is always listed as "Hexylene Glycol." In industrial procurement and chemical documentation, the IUPAC name 2-methylpentane-2,4-diol or the abbreviation MPD are used. The names "methyl-2,4-pentanediol," "2-metil-2,4-pentanediol" (Spanish/Portuguese spelling), and "2,4-pentandiol" are informal or regional synonyms for the same compound.

Q: What is the structure (condensed formula) of 2-methyl-2,4-pentanediol?

The condensed structural formula of 2-methyl-2,4-pentanediol is (CH₃)₂C(OH)–CH₂–CH(OH)–CH₃. Expanded: the molecule has a 5-carbon backbone with a methyl branch at C-2, giving it six carbons total. The C-2 position bears a tertiary hydroxyl group (–OH flanked by two methyl groups and the chain), while C-4 bears a secondary hydroxyl. This branched, asymmetric structure prevents molecular packing, resulting in a low-melting (−50°C), low-viscosity liquid with strong and broad solvency. The molecular formula is C₆H₁₄O₂, MW = 118.17 g/mol.

Q: What is the difference between 2-methyl-2,4-pentanediol and 4-methyl-2,4-pentanediol?

4-Methyl-2,4-pentanediol (CAS 2004-69-5) is a positional isomer where the methyl branch is at C-4 instead of C-2. It is structurally distinct from 2-methyl-2,4-pentanediol and has different physicochemical properties and commercial applications. Standard commercial hexylene glycol / MPD always refers to the 2-methyl-2,4-pentanediol isomer (CAS 107-41-5). When specifying orders, always confirm the CAS number 107-41-5 to avoid confusion between isomers.

Q: Is hexylene glycol safe for cosmetic use? What is its EU regulatory status?

Hexylene glycol (2-methyl-2,4-pentanediol) is approved for cosmetic use under EU Cosmetics Regulation (EC) No 1223/2009 and is listed in the CosIng database. The EU's Scientific Committee on Consumer Safety (SCCS) has assessed hexylene glycol and considers it safe for use in cosmetics at concentrations up to 7.5% in leave-on products. It is widely used at 0.5–3.0% as a humectant, emollient, and preservative booster. It is not classified as a CMR (carcinogenic, mutagenic, or reprotoxic) substance and is not restricted or prohibited in EU cosmetics. Our cosmetic-grade MPD meets all required purity standards for personal care applications.

Q: How is 2-methyl-2,4-pentanediol manufactured?

MPD is produced industrially via a two-step process: (1) Aldol condensation of acetone to form diacetone alcohol (DAA): 2 CH₃COCH₃ → (CH₃)₂C(OH)CH₂COCH₃; (2) Selective catalytic hydrogenation of DAA over a copper or nickel catalyst under moderate hydrogen pressure to give MPD: (CH₃)₂C(OH)CH₂COCH₃ + H₂ → (CH₃)₂C(OH)CH₂CH(OH)CH₃. The selective hydrogenation of the ketone group (leaving the tertiary alcohol intact) requires careful catalyst and condition control. The product is purified by multi-stage distillation to ≥99.5% purity. Raw material cost is therefore linked to acetone market prices.