Diphenyl ether

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C₁₂H₁₀O · 170.21 g/mol

IUPAC name: phenoxybenzene

Also called diphenyl oxide, phenyl ether

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Drawn from its SMILES with RDKit

WarningCauses serious eye irritation · Very toxic to aquatic life · Very toxic to aquatic life with long lasting effects · Toxic to aquatic life with long lasting effects

Names and identifiers

IUPAC name: phenoxybenzene
Synonyms: diphenyl oxide, phenyl ether, Diphenyl oxide
+ 36 more
Phenoxybenzene, Phenyl ether, Benzene, 1,1'-oxybis-, Diphenylether, Oxybisbenzene, Phenyl oxide, Biphenyl oxide, Geranium crystals, Oxydiphenyl, Chemcryl JK-EB, Benzene, phenoxy-, 1,1'-Oxybis(benzene), 1,1'-Oxybisbenzene, Ether, diphenyl, FEMA No. 3667, DTXSID9021847, 3O695R5M1U, NSC-19311, DTXCID701847, CHEBI:39258, phenoxy benzene, Phenyl ether (vapor), RefChem:5768, 202-981-2, Oxydibenzene, 1,1'-oxydibenzene, Ether, diphenyl-, Phenyl ether, vapor, Diphenylaether, Diphenyloxid, phenoxy-benzene, NSC 19311, 1,1'-oxybis-benzene, MFCD00003034, diphenyloxide, diphenyl-ether
Molecular formula: C₁₂H₁₀O
Empirical formula: C₁₂H₁₀O
Molecular weight: 170.21 g/mol
Exact mass: 170.07316
CAS number: 101-84-8
PubChem CID: 7583
Canonical SMILES: C1=CC=C(C=C1)OC2=CC=CC=C2
Isomeric SMILES: C1=CC=C(C=C1)OC2=CC=CC=C2
InChI: InChI=1S/C12H10O/c1-3-7-11(8-4-1)13-12-9-5-2-6-10-12/h1-10H
InChIKey: USIUVYZYUHIAEV-UHFFFAOYSA-N
Molfile

Names, InChI and the identifiers from PubChem, retrieved 2026-10-14.

Physical properties

TemperaturePressureDensity

Appearance: Colorless crystals or liquid[6]
7 values
From Hazardous Substances Data Bank (HSDB), the most authoritative source here.
Value As written Source
– Diphenyl oxide appears as colorless liquid with a mild pleasant odor. May float or sink in water. Freezing point is 81 °F. (USCG, 1999) [1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
– Liquid; CBI; Other Solid; Dry Powder [2] EPA Chemical Data Reporting (CDR)
– COLOURLESS LIQUID OR CRYSTALS WITH CHARACTERISTIC ODOUR. [3] ILO-WHO International Chemical Safety Cards (ICSCs)
– Colorless, crystalline solid or liquid (above 82 °F) with a geranium-like odor. [4] Occupational Safety and Health Administration (OSHA)
– Colorless, crystalline solid or liquid (above 82 °F) with a geranium-like odor. [5] The National Institute for Occupational Safety and Health (NIOSH)
–shown Colorless crystals or liquid [6] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 466
– Colorless, crystalline solid or liquid (above 82 degrees F) [6] Hazardous Substances Data Bank (HSDB)cites NIOSH. NIOSH Pocket Guide to Chemical Hazards. Department of Health & Human Services, Centers for Disease Control & Prevention. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2010-168 (2010). Available from: https://www.cdc.gov/niosh/npg
Odor: Geranium-like odor[6]
Melting point: 26.8 °C (80.3 °F, NTP 1992)[1]
4 values
4 of 4 sources agree on it (most common value).
Value As written Source
26.8 °Cshown 80.3 °F (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
28 °C 28 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs)
28 °C 82 °F [4] Occupational Safety and Health Administration (OSHA)
28 °C 82 °F [5] The National Institute for Occupational Safety and Health (NIOSH)
Boiling point: 257.93 °C (496.27 °F) at 760 mmHg (NTP, 1992)[1]
5 values
5 of 5 sources agree on it (most common value).
Value As written Source
257.9 °Cshown 496.27 °F at 760 mmHg (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
257 °C 257 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs)
259 °C 498 °F [4] Occupational Safety and Health Administration (OSHA)
259 °C 259 °C @760 [mm Hg] [7] PAC Chemical Database, U.S. Department of Energy
259 °C 498 °F [5] The National Institute for Occupational Safety and Health (NIOSH)
Density: 1.0728 @ 20°C[7]
5 values
5 of 5 sources agree on it (most common value).
Value As written Source
– 1.07 at 80.6 °F (USCG, 1999) - Denser than water [1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
– Relative density (water = 1): 1.08 [3] ILO-WHO International Chemical Safety Cards (ICSCs)
– 1.08 [4] Occupational Safety and Health Administration (OSHA)
–shown 1.0728 @ 20°C [7] PAC Chemical Database, U.S. Department of Energy
– 1.08 [5] The National Institute for Occupational Safety and Health (NIOSH)
2 more values were reported but failed the checks (unreadable or out of range), so they are not shown.
Solubility in water: Solubility in water, g/100ml: 0.002 (very poor)[3]
4 values
From ILO-WHO International Chemical Safety Cards (ICSCs), the most authoritative source here.
Value As written Source
– Insoluble (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
– In water, 18 mg/L at 25 °C [6] Hazardous Substances Data Bank (HSDB)cites Banerjee S et al; Environ Sci Technol 14: 1227-9 (1980)
–shown Solubility in water, g/100ml: 0.002 (very poor) [3] ILO-WHO International Chemical Safety Cards (ICSCs)
– Insoluble [5] The National Institute for Occupational Safety and Health (NIOSH)
log P: 4.21[3]
2 values
2 of 2 sources agree on it (most common value).
Value As written Source
– log Kow = 4.21 [6] Hazardous Substances Data Bank (HSDB)cites Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995., p. 97
–shown 4.21 [3] ILO-WHO International Chemical Safety Cards (ICSCs)
pKa: Reported, but no value passed the checks.
The value and why
pK(BH+) = 5.79 at 25 °C /negative logarithm of ionization constant of protonated base/ (could not be read; source [6])
Vapor pressure: Vapor pressure, Pa at 25 °C: 2.7[3]
5 values
3 of 4 sources agree on it (most common value).
Value As written Source
0.02 mmHg 0.02 mmHg at 77 °F (NIOSH, 2024) [1] CAMEO Chemicals
0.0213 mmHg Vapor pressure = 0.0213 mm Hg at 25 °C [6] Hazardous Substances Data Bank (HSDB)cites Patty, F. (ed.). Industrial Hygiene and Toxicology: Volume II: Toxicology. 2nd ed. New York: Interscience Publishers, 1963., p. 1699
0.0225 mmHg 0.0225 mm Hg at 25 °C [6] Hazardous Substances Data Bank (HSDB)cites Ambrose D et al; J Chem Thermodyn 8: 165-78 (1976)
0.02 mmHgshown Vapor pressure, Pa at 25 °C: 2.7 [3] ILO-WHO International Chemical Safety Cards (ICSCs)
0.02 mmHg 0.02 mmHg at 77 °F [4] Occupational Safety and Health Administration (OSHA)
1 more value was reported but failed the checks (unreadable or out of range), so it is not shown.
Flash point: 115 °C c.c.[3]
5 values
5 of 5 sources agree on it (most common value).
Value As written Source
115 °C 239 °F (NTP, 1992) [1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
115 °C 239 °F (115 °C) (Closed cup) [6] Hazardous Substances Data Bank (HSDB)cites National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 325-54
115 °Cshown 115 °C c.c. [3] ILO-WHO International Chemical Safety Cards (ICSCs)
115 °C 239 °F [4] Occupational Safety and Health Administration (OSHA)
115 °C 239 °F [5] The National Institute for Occupational Safety and Health (NIOSH)
Autoignition temperature: 618 °C (1144 °F).[6]
3 values
Sources disagree; from Hazardous Substances Data Bank (HSDB), the most authoritative.
Value As written Source
620 °C 1148 °F (USCG, 1999) [1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
618 °Cshown 1144 °F (618 °C). [6] Hazardous Substances Data Bank (HSDB)cites National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 325-54
610 °C 610 °C [3] ILO-WHO International Chemical Safety Cards (ICSCs)
Viscosity: Reported, but no value passed the checks.
The value and why
3.4909X10-3 Pa-sec at melting point (could not be read; source [6])

Value	As written	Source
–	Diphenyl oxide appears as colorless liquid with a mild pleasant odor. May float or sink in water. Freezing point is 81 °F. (USCG, 1999)	[1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
–	Liquid; CBI; Other Solid; Dry Powder	[2] EPA Chemical Data Reporting (CDR)
–	COLOURLESS LIQUID OR CRYSTALS WITH CHARACTERISTIC ODOUR.	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–	Colorless, crystalline solid or liquid (above 82 °F) with a geranium-like odor.	[4] Occupational Safety and Health Administration (OSHA)
–	Colorless, crystalline solid or liquid (above 82 °F) with a geranium-like odor.	[5] The National Institute for Occupational Safety and Health (NIOSH)
–shown	Colorless crystals or liquid	[6] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sr.; Hawley's Condensed Chemical Dictionary 15th Edition. John Wiley & Sons, Inc. New York, NY 2007., p. 466
–	Colorless, crystalline solid or liquid (above 82 degrees F)	[6] Hazardous Substances Data Bank (HSDB)cites NIOSH. NIOSH Pocket Guide to Chemical Hazards. Department of Health & Human Services, Centers for Disease Control & Prevention. National Institute for Occupational Safety & Health. DHHS (NIOSH) Publication No. 2010-168 (2010). Available from: https://www.cdc.gov/niosh/npg

Value	As written	Source
26.8 °Cshown	80.3 °F (NTP, 1992)	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
28 °C	28 °C	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
28 °C	82 °F	[4] Occupational Safety and Health Administration (OSHA)
28 °C	82 °F	[5] The National Institute for Occupational Safety and Health (NIOSH)

Value	As written	Source
257.9 °Cshown	496.27 °F at 760 mmHg (NTP, 1992)	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
257 °C	257 °C	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
259 °C	498 °F	[4] Occupational Safety and Health Administration (OSHA)
259 °C	259 °C @760 [mm Hg]	[7] PAC Chemical Database, U.S. Department of Energy
259 °C	498 °F	[5] The National Institute for Occupational Safety and Health (NIOSH)

Value	As written	Source
–	1.07 at 80.6 °F (USCG, 1999) - Denser than water	[1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
–	Relative density (water = 1): 1.08	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–	1.08	[4] Occupational Safety and Health Administration (OSHA)
–shown	1.0728 @ 20°C	[7] PAC Chemical Database, U.S. Department of Energy
–	1.08	[5] The National Institute for Occupational Safety and Health (NIOSH)

Value	As written	Source
–	Insoluble (NTP, 1992)	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
–	In water, 18 mg/L at 25 °C	[6] Hazardous Substances Data Bank (HSDB)cites Banerjee S et al; Environ Sci Technol 14: 1227-9 (1980)
–shown	Solubility in water, g/100ml: 0.002 (very poor)	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
–	Insoluble	[5] The National Institute for Occupational Safety and Health (NIOSH)

Value	As written	Source
–	log Kow = 4.21	[6] Hazardous Substances Data Bank (HSDB)cites Hansch, C., Leo, A., D. Hoekman. Exploring QSAR - Hydrophobic, Electronic, and Steric Constants. Washington, DC: American Chemical Society., 1995., p. 97
–shown	4.21	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Value	As written	Source
0.02 mmHg	0.02 mmHg at 77 °F (NIOSH, 2024)	[1] CAMEO Chemicals
0.0213 mmHg	Vapor pressure = 0.0213 mm Hg at 25 °C	[6] Hazardous Substances Data Bank (HSDB)cites Patty, F. (ed.). Industrial Hygiene and Toxicology: Volume II: Toxicology. 2nd ed. New York: Interscience Publishers, 1963., p. 1699
0.0225 mmHg	0.0225 mm Hg at 25 °C	[6] Hazardous Substances Data Bank (HSDB)cites Ambrose D et al; J Chem Thermodyn 8: 165-78 (1976)
0.02 mmHgshown	Vapor pressure, Pa at 25 °C: 2.7	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
0.02 mmHg	0.02 mmHg at 77 °F	[4] Occupational Safety and Health Administration (OSHA)

Value	As written	Source
115 °C	239 °F (NTP, 1992)	[1] CAMEO Chemicalscites National Toxicology Program, Institute of Environmental Health Sciences, National Institutes of Health (NTP). 1992. National Toxicology Program Chemical Repository Database. Research Triangle Park, North Carolina.
115 °C	239 °F (115 °C) (Closed cup)	[6] Hazardous Substances Data Bank (HSDB)cites National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 325-54
115 °Cshown	115 °C c.c.	[3] ILO-WHO International Chemical Safety Cards (ICSCs)
115 °C	239 °F	[4] Occupational Safety and Health Administration (OSHA)
115 °C	239 °F	[5] The National Institute for Occupational Safety and Health (NIOSH)

Value	As written	Source
620 °C	1148 °F (USCG, 1999)	[1] CAMEO Chemicalscites U.S. Coast Guard. 1999. Chemical Hazard Response Information System (CHRIS) - Hazardous Chemical Data. Commandant Instruction 16465.12C. Washington, D.C.: U.S. Government Printing Office.
618 °Cshown	1144 °F (618 °C).	[6] Hazardous Substances Data Bank (HSDB)cites National Fire Protection Association; Fire Protection Guide to Hazardous Materials. 14TH Edition, Quincy, MA 2010, p. 325-54
610 °C	610 °C	[3] ILO-WHO International Chemical Safety Cards (ICSCs)

Each value as its source reports it, with the source's number after it (listed under References). Where several sources report a property, the row shows the value most of them agree on, the rule the app uses; open the values to see every one.

Calculated

Heavy atoms: 13
Rings: 2
Aromatic rings: 2
Fraction sp³ carbons (Fsp3): 0
H-bond donors: 0
H-bond acceptors: 1
Rotatable bonds: 2
TPSA (Å²): 9.2
Formal charge: 0
XLogP3: 4.2 PubChem
Complexity: 116 PubChem
Stereocenters: None
Double-bond geometry: None specified
Point group: C2 of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)

Elemental analysis

C84.68%
H5.92%
O9.40%

Isotope pattern

Each peak is a nominal mass with its abundance-weighted exact mass, as a percentage of the tallest, from IUPAC natural isotope abundances.

Computed from the structure with RDKit 2026.09 when this page was built, beside PubChem's own computed values from its record; where the two differ, both are shown.

Predicted

log P: 3.48 Crippen (Wildman and Crippen 1999)
log S (water solubility): -3.64 ESOL (Delaney 2004), log mol/L
Synthetic accessibility: 1.06 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

Molecular weight ≤ 500: 170.21
log P ≤ 5 (Crippen): 3.48
H-bond donors ≤ 5: 0
H-bond acceptors ≤ 10: 1

Passes all four rules.

¹³C NMR shifts, predicted

Predictions, not measurements; each names its method. A measured log P, where a source reports one, is under Physical properties.

Safety

Warning

Most widely reported: 2,199 company reports to ECHA. Source [8].

Harmful or irritant
Environmental hazard

NFPA 704[6]

H319Causes serious eye irritation (84.8% of reports)
H400Very toxic to aquatic life (16.1% of reports)
H410Very toxic to aquatic life with long lasting effects (10.3% of reports)
H411Toxic to aquatic life with long lasting effects (78.8% of reports)

Precautionary statements: P264+P265, P273, P280, P305+P351+P338, P337+P317, P391, P501

View all classifications (3)

[8] European Chemicals Agency (ECHA)This chemical does not meet GHS hazard criteria for 0.5% (12 of 2199) of reports.
[8] European Chemicals Agency (ECHA) · 2,199 reports · WarningH319, H400, H410, H411
[6] Hazardous Substances Data Bank (HSDB) · WarningH319, H401, H411

Exposure limits

PEL-TWA (8-Hour Time Weighted Average): 1 ppm (7 mg/m³)[4]
PEL: TWA 1 ppm (7 mg/m3)[5]
TLV: 1 ppm as TWA; 2 ppm as STEL.[3]
TLV-TWA (Time Weighted Average): 1 ppm [1979][4]
TLV-STEL (Short Term Exposure Limit): 2 ppm [1979][4]
IDLH: 100 ppm [From npg: Phenyl ether (vapor)] (NIOSH, 2024)[1]

First aid

Eyes: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. Immediately transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop. Skin: Immediately flood affected skin with water while removing and isolating all contaminated clothing.[1]
(General first aid procedures) Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately. Skin: Soap wash promptly - If this chemical contacts the skin, promptly wash the contaminated skin with soap and water. If this chemical penetrates the clothing, promptly remove the clothing and wash the skin with soap and water. Get medical attention promptly. Breathing: Respiratory support[5]
Fresh air, rest.[3]
Remove contaminated clothes. Rinse and then wash skin with water and soap.[3]

Storage

Separated from strong oxidants. Store in an area without drain or sewer access. Provision to contain effluent from fire extinguishing.[3]
Conditions for safe storage, including any incompatibilities. Keep container tightly closed in a dry and well-ventilated place. Storage class (TRGS 510): Non Combustible Solids.[6]

Incompatibilities

Incompatible materials: Strong oxidizing agents.[6]
Strong oxidizers may cause fires and explosions. Attacks some plastics, rubber, and coatings.[6]
Strong oxidizers. (vapor)[6]
Strong oxidizers[5]

Safety data sheets on the supplier’s page: AbaChemScene, InvivoChem, AgroIntelBioScan.com.

Always read the supplier’s safety data sheet before working with it.

Spectra

Experimental spectra held by these sources; each link opens the source's own record.

Literature

Reading PubChem, OpenAlex and GSRS…

Bioactivity

Reading ChEMBL…

References

[1]CAMEO Chemicals · Public domain (NOAA) · via PubChem · retrieved 2026-10-14
[2]EPA Chemical Data Reporting (CDR) · Public domain (US EPA) · via PubChem · retrieved 2026-10-14
[3]ILO-WHO International Chemical Safety Cards (ICSCs) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
[4]Occupational Safety and Health Administration (OSHA) · Public domain (US DOL) · via PubChem · retrieved 2026-10-14
[5]The National Institute for Occupational Safety and Health (NIOSH) · Public domain (US CDC) · via PubChem · retrieved 2026-10-14
[6]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
[7]PAC Chemical Database, U.S. Department of Energy · Public domain (US DOE) · via PubChem · retrieved 2026-10-14
[8]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
[9]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
[10]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
[11]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
[12]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
[13]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
[14]MassBank Europe · Linked only · via PubChem · retrieved 2026-10-14
·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
·Literature on PubChem

Data last updated 2026-10-14.