2-Ethylhexanol (abbreviated 2-EH) is an organic compound with the chemical formula CH₃CH₂CH₂CH₂CH(CH₂CH₃)CH₂OH. It is a branched, eight-carbon chiral alcohol. It is a colorless liquid that is poorly soluble in water but soluble in most organic solvents. It is produced on a large scale (>2,000,000,000 kg/y) for use in numerous applications such as solvents, flavors, and fragrances and especially as a precursor for production of other chemicals such as emollients and plasticizers.^[3] It is encountered in plants, fruits, and wines.^[4][5] The odor has been reported as "heavy, earthy, and slightly floral" for the R enantiomer and "a light, sweet floral fragrance" for the S enantiomer.^[6][7]

Quick Facts Names, Identifiers ...

2-Ethylhexanol

Names
Preferred IUPAC name 2-Ethylhexan-1-ol[1]
Other names isooctyl alcohol, 2-ethylhexanol
Identifiers
CAS Number	104-76-7 Y
3D model (JSmol)	Interactive image
Beilstein Reference	1719280
ChEBI	CHEBI:16011 Y
ChEMBL	ChEMBL31637 Y ChEMBL1229918 Y
ChemSpider	7434 Y 5360145 (R enantiomer) Y 5360146 (S enantiomer) Y
ECHA InfoCard	100.002.941
EC Number	203-234-3
KEGG	C02498 N
MeSH	2-ethylhexanol
PubChem CID	7720 6991979 (R enantiomer) 6991980 (S enantiomer)
UNII	XZV7TAA77P Y
CompTox Dashboard (EPA)	DTXSID5020605
InChI InChI=1S/C8H18O/c1-3-5-6-8(4-2)7-9/h8-9H,3-7H2,1-2H3 Y Key: YIWUKEYIRIRTPP-UHFFFAOYSA-N Y
SMILES CCCCC(CC)CO
Properties
Chemical formula	CH3CH2CH2CH2CH(CH2CH3)CH2OH
Molar mass	130.231 g·mol−1
Appearance	Colourless liquid
Density	833 mg/mL
Melting point	−76 °C (−105 °F; 197 K)
Boiling point	180 to 186 °C; 356 to 367 °F; 453 to 459 K
log P	2.721
Vapor pressure	30 Pa (at 20 °C)
Refractive index (nD)	1.431
Thermochemistry
Heat capacity (C)	317.5 J/(K·mol)
Std molar entropy (S⦵298)	347.0 J/(K·mol)
Std enthalpy of formation (ΔfH⦵298)	−433.67–−432.09 kJ/mol
Std enthalpy of combustion (ΔcH⦵298)	−5.28857–−5.28699 MJ/mol
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Mildly toxic
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H312, H315, H318, H335
Precautionary statements	P261, P280, P305+P351+P338
Flash point	81 °C (178 °F; 354 K)
Autoignition temperature	290 °C (554 °F; 563 K)
Explosive limits	0.88–9.7%
Lethal dose or concentration (LD, LC):
LD50 (median dose)	1.97 g/kg (dermal, rabbit) 3.73 g/kg (oral, rat)
NIOSH (US health exposure limits):
PEL (Permissible)	none[2]
REL (Recommended)	TWA 50 ppm (270 mg/m3) (skin)[2]
IDLH (Immediate danger)	N.D.[2]
Related compounds
Related alkanol	Propylheptyl alcohol
Related compounds	2-Methylhexane 3-Methylhexane Valnoctamide 2-Methylheptane 3-Methylheptane Valpromide 2-Ethylhexanoic acid
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

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The branching in 2-ethylhexanol inhibits crystallization. Esters of 2-ethylhexanol are similarly affected, which together with low volatility, is the basis of applications in the production of plasticizers and lubricants, where its presence helps reduce viscosity and lower freezing points. Because 2-ethylhexanol is a fatty alcohol, its esters have emollient properties. Representative is the diester bis(2-ethylhexyl) phthalate (DEHP), commonly used in PVC. The triester tris (2-Ethylhexyl) trimellitate (TOTM) is another common plasticizer produced via the esterification of three 2-ethylhexanol per trimellitic acid.

It is also commonly used as a low volatility solvent. 2-Ethylhexanol can also be used as a cetane improver when reacted with nitric acid. It also used to react with epichlorohydrin and sodium hydroxide to produce 2-Ethylhexyl glycidyl ether which is then used as an epoxy reactive diluent in various coatings, adhesives and sealants applications. It can be used in the development of photos, production of rubber and extraction of oil and gas.^[8]

2-Ethylhexanol is produced industrially by the aldol condensation of n-butyraldehyde, followed by hydrogenation of the resulting hydroxyaldehyde. About 2,500,000 tons are prepared in this way annually.^[9][10]

The n-butyraldehyde is made by hydroformylation of propylene, either in a self-contained plant or as the first step in a fully integrated facility. Most facilities make n-butanol and isobutanol in addition to 2-ethylhexanol. Alcohols prepared in this way are sometimes referred to as oxo alcohols. The overall process is very similar to that of the Guerbet reaction, by which it may also be produced.^[11]

2-Ethylhexanol exhibits low toxicity in animal models, with LD50 ranging from 2-3 g/kg (rat).^[3] 2-Ethylhexanol has been identified as a cause of indoor air quality related health problems, such as respiratory system irritation, as a volatile organic compound. 2-Ethylhexanol is emitted to air from a PVC flooring installed on concrete that had not been dried properly.^[12][13]

2-Ethylhexanol has been linked to developmental toxicity (increased incidence of skeletal malformations in fetuses).^[14] This is thought to be a result of metabolism of 2-ethylhexanol into 2-ethylhexanoic acid via oxidation of the primary alcohol.^[15][16] The teratogenicity of 2-ethylhexanoic acid, as well as similar substances such as valproic acid, has been well established.^{[17][18][19][20][21]}

Although isooctanol (and the derived isooctyl prefix) is commonly used in industry to refer to 2-ethylhexanol and its derivatives, IUPAC naming conventions^[22] dictate that this name is properly applied to another isomer of octanol, 6-methylheptan-1-ol. The Chemical Abstracts Service likewise indexes isooctanol (CAS# 26952-21-6) as 6-methylheptan-1-ol.

• 2-Ethylhexanoic acid