Basic information
- Standard SMILES
C1=Cc2ccccc2C1- InChIKey
YBYIRNPNPLQARY-UHFFFAOYSA-N- Molecular formula
- C9H8
- Average molar mass
- 116.16 g/mol
- Monoisotopic mass
- 116.06260026
Overview
Indene appears as a colorless liquid derived from coal tar. Fp: -2 °C; bp:182 °C. Density 0.997 g cm-3. Insoluble in water but soluble in organic solvents.
Names & identifiers
- Preferred name
- Indene
- IUPAC
- 1H-indene
- English name
- Indene
- Molecular formula
- C9H8
- Molecular weight
- 116.16
Names & synonyms
INDENE1H-Indene95-13-6IndonaphtheneIndenDTXSID8042052NSC 927067H8Y6LB8ANSC-9270DTXCID6022052CHEBI:41921RefChem:790898
Show more names
Technicalindenendene1-indeneIndene >Indene,90+%Indene techIndene Odor
CHEBI:37910202-393-6MFCD00003777CHEMBL1928129003-64-9Indenyl radicalHSDB 5286EINECS 202-393-6
Database identifiers
- CAS
71551-80-9、9003-64-9、95-13-6- PubChem CID
- 7219
- DTXSID
DTXSID8042052- ChEMBL
CHEMBL192812、CHEMBL506735- ChEBI
CHEBI:41921- UNII
- 67H8Y6LB8A
- EC Number
- 202-393-6
- Nikkaji
- J4.708B
Properties
Computed structural properties
- XLogP
- 2.9
- Topological polar surface area
- 0 Ų
- Hydrogen bond donors
- 0
- Hydrogen bond acceptors
- 0
- Rotatable bonds
- 0
- Heavy atoms
- 9
- Formal charge
- 0
- Complexity
- 124
Experimental & physicochemical properties
Chemical Classes
Other Classes -> Aromatic Hydrocarbons
Flammable agents - 2nd degree
SpringerMaterials Properties13C nuclear magnetic resonance spectrum
FragrancesFragrance Ingredient (1H-Indene) -> IFRA transparency List
LogPLog Kow = 2.92
Density
0.997 (NIOSH, 2024) - Less dense than water; will float
0.9968 @ 20 °C/4 °C
0.997
0.996 @25 °C
0.997
Color/Form
LIQUID
Colorless liquid
Colorless liquid [Note: A solid below 29 degrees F].
Solubility
Insoluble (NIOSH, 2024)
INSOL IN WATER, MISCIBLE WITH MOST ORGANIC SOLVENTS
SOL IN ALL PROPORTIONS IN ALC, ETHER, N BENZENE, PYRIMIDENE, CARBON DISULFIDE
Soluble in ethanol; it is miscible with diethyl ether, naphtha, pyridine, carbon tetrachloride, chloroform, and carbon disulfide
Insoluble
Flash Point
173 °F (NIOSH, 2024)
173 °F
173 °F
173 °F
173 °F
Boiling Point
359 °F at 760 mmHg (NIOSH, 2024)
181.6 °C 760 MM HG
359 °F
182 °C @760 [mm Hg]
359 °F
Melting Point
29 °F (NIOSH, 2024)
-1.8 °C
29 °F
-1.5 °C
29 °F
Odor ThresholdOdor Threshold Low: 0.0042 [ppm]
Vapor Pressure
1.1 [mmHg]
1.1 mm Hg at 25 °C
0.75 [mm Hg] @12 °C
Physicochemical properties
- Melting point
- -5 · -5--3 °C (lit.)
- Boiling point
- 181 · 181-182 °C (lit.)
- Density
- 0.996 g/mL · 0.996 g/mL at 25 °C (lit.)
- vapor pressure
- 1.7 hPa · 1.7 hPa (20 °C)
- refractive index
- 20 · n20/D 1.595(lit.)
- Flash point
- 138 °F · 138 °F
- storage temp.
- 2 · 2-8°C
- solubility
- organic solvents: miscible
- pka
- 20 · 20(at 25℃)
- form
- Crystalline Powder
- color
- White to pale yellow
- Odor Threshold
- 0.0038 ppm · 0.0038ppm
- Water Solubility
- INSOLUBLE
- Specific Heat Capacity
- 1.61 J/ · Cp(liquid): 1.61 J/(g·K), at 25℃
- Sensitive
- Light Sensitive
- Merck
- 14 · 14,4939
- BRN
- 635873 · 635873
- Henry's Law Constant
- 6.2 · 6.2×10-3 mol/(m3Pa) at 25℃, HSDB (2015)
- Exposure limits
- 50 mg/m3 · PC-TWA:50 mg/m3
- Stability
- 80 · Stable, but air and light sensitive; may polymerize upon exposure to light. Typically contains aroung 80 - 100 ppm of p-tert-butylcatechol as inhibitor. Refrigerate. Flammable. Incompatible with strong oxidizing agents.
- Cosmetics Ingredients Functions
- PERFUMING
- InChI
- 1S/C9H8/c1-2-5-9-7-3-6-8(9)4-1/h1-6H,7H2
- InChIKey
- YBYIRNPNPLQARY-UHFFFAOYSA-N
- SMILES
- C1C=Cc2ccccc12
- LogP
- 3.02 at · 3.02 at 25℃ and pH6.4
- FDA 21 CFR
- 175.105 · 175.105
- Indirect Additives used in Food Contact Substances
- INDENE
- CAS DataBase Reference
- 95 · 95-13-6(CAS DataBase Reference)
- EWG's Food Scores
- 1 · 1
- FDA UNII
- 67 H8Y6LB8A · 67H8Y6LB8A
- NIST Chemistry Reference
- Indene(95-13-6)
- EPA Substance Registry System
- Indene (95-13-6)
- UNSPSC Code
- 12352100 · 12352100
- NACRES
- 22 · NA.22
- Symbol(GHS)
- 2 · GHS02,GHS08
- Signal word
- Danger
- Hazard statements
- 226 · H226-H304
- Precautionary statements
- 210 · P210-P233-P240-P241-P301+P310-P331
- PPE
- Eyeshields, Faceshields, Gloves, type ABEK (EN14387) respirator filter
- Hazard Codes
- Xn
- Risk Statements
- 10 · 10-65-36/37/38-20
- Safety Statements
- 23 · 23-24/25-62-37/39-26
- OEB
- A
- OEL
- 10 ppm · TWA: 10 ppm (45 mg/m3)
- RIDADR
- 3295 · UN 3295 3/PG 3
- WGK Germany
- 1 · 1
- RTECS
- 8225000 · NK8225000
- F
- 8 · 8
- TSCA
- TSCA listed
- HS Code
- 2902 · 2902 90 00
- HazardClass
- 3 · 3
- PackingGroup
- III
- Storage Class
- 3 · 3 - Flammable liquids
- Hazard Classifications
- 1 Flam · Asp. Tox. 1Flam. Liq. 3
- Hazardous Substances Data
- 95 · 95-13-6(Hazardous Substances Data)
- REACH Registrations
- Active
- Limited Quantities
- 5 L · 5.0 L (1.3 gallons) (liquid)
- Excepted Quantities
- Max Inner Pack (30g or 30ml) and Max Outer Pack (1Kg or 1L)
Safety & regulation
GHS classification
GHS Classification
This chemical does not meet GHS hazard criteria for 0.5% (2 of 400) of reports.
Danger
H226 (99.2%): Flammable liquid and vapor [Warning Flammable liquids]
P210, P233, P240, P241, P242, P243, P264, P264+P265, P273, P280, P301+P316, P302+P352, P303+P361+P353, P305+P351+P338, P321, P331, P332+P317, P337+P317, P362+P364, P370+P378, P391, P403+P235, P405, and P501 (click each P-code to see the statement)
Aggregated GHS information provided per 400 reports by companies from 16 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.
Danger
Hazard information
Regulatory Information
Chemical: 1H-Indene
1H-Indene is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of 1H-Indene are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)
Status: Active Update: 26-02-2019 https://echa.europa.eu/registration-dossier/-/registered-dossier/27751
Indene: Does not have an individual approval but may be used under an appropriate group standard
The New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.)
DOT LabelCombustible Liquid
Fire HazardsExcerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:
Fire PotentialDEFLAGRATES ON HEATING. /INDENE PICRATE/
Health HazardsExcerpt from NIOSH Pocket Guide for Indene:
Hazards SummaryAnimals exposed to 800-900 ppm for six 7-hour periods show evidence of liver and kidney injury. [ACGIH]
Reactive GroupHydrocarbons, Aromatic
Reactivity AlertsPolymerizable
Reactivity Profile
INDENE is combustible (flash point between 140 °F and 200 °F). Polymerizes and oxidizes on standing in the air. This reaction is accelerated by heating, acids, and catalysts, including peroxides. Has exploded during nitration with a mixture of H2SO4 and HNO3.
Flammable LimitsClass IIIA Combustible Liquid: Fl.P. at or above 140 °F and below 200 °F.
Air and Water ReactionsPeroxide formation with air with initiation of polymerization
NIOSH RecommendationsRecommended Exposure Limit: 10 Hr Time-Weighted Avg: 10 ppm (45 mg/cu m).
Safety & protection
Fire FightingExcerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:
First Aid
Excerpt from NIOSH Pocket Guide for Indene:
(General first aid procedures)
Nonfire Spill ResponseExcerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:
Disposal Methods
SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.
Preventive Measures
The worker should wash daily at the end of each work shift.
Work clothing that becomes wet or significantly contaminated should be removed and replaced.
Isolation and EvacuationExcerpt from ERG Guide 128 [Flammable Liquids (Water-Immiscible)]:
Respirator RecommendationsImportant additional information about respirator selection
Threshold Limit Values (TLV)
5.0 [ppm]
8 hr Time Weighted Avg (TWA): 5 ppm.
Excursion Limit Recommendation: Excursions in worker exposure levels may exceed 3 times the TLV-TWA for no more than a total of 30 minutes during a work day, and under no circumstances should they exceed 5 times the TLV-TWA, provided that the TLV-TWA is not exceeded.
5 ppm [2007]
Permissible Exposure Limit (PEL)
10 ppm (45 mg/m³) OSHA Construction and Maritime industries only.
none See Appendix G
Protective Action Criteria (PAC)
70 [mg/m3]
100 [mg/m3]
620 [mg/m3]
Recommended Exposure Limit (REL)
10 ppm (45 mg/m³)
TWA 10 ppm (45 mg/m3)
Personal Protective Equipment (PPE)
Excerpt from NIOSH Pocket Guide for Indene:
Wear appropriate personal protective clothing to prevent skin contact.
Wear appropriate eye protection to prevent eye contact.
Toxicology
Body Burden
Indene was detected in respiratory gas from 7 of 8 male volunteers (3 smokers) at a concn range of 0.14-83 ug/hr-expired air; according to this study, indene may result from or be related to normal human metabolism(1). Indene was found at an average concn of 0.138 ng/L in 59 of 387 expired air samples obtained from 54 nonsmoking-volunteers(2).
Target OrgansEyes, skin, respiratory system, liver, kidneys, spleen
Environmental Fate
TERRESTRIAL FATE: The estimated Koc value of 540(1-2,SRC) suggests that indene will have low mobility in soil(3). If spilled on soil surfaces, some indene may photolyze(4,SRC) or volatilize into the air (estimated Henry's Law constant of 1.59X10-3 atm-cu m/mol at 25 °C(5)). However, adsorption may limit these processes(SRC). Limited data suggest indene is biodegradable in soil(6-7).
AQUATIC FATE: Based on the estimated Koc value of 540(1-2,SRC), indene may adsorb to sediment; indene was found in a river sediment(3). Oxidation via reaction with sunlight produced alkyl peroxy radicals is very slow (estimated half-life of 1,100 days(4)). Limited data suggest indene is biodegradable. Indene may be susceptible to some direct photolysis in sunlight(5); however, this is not expected to be an important removal process(SRC). Indene is not expected to hydrolyze in the aquatic environments(SRC). Volatilization from water is fast with estimated half-lives of 3.7 hrs and 4.4 days from a model river and model lake, respectively(1,SRC).
ATMOSPHERIC FATE: Based upon a measured vapor pressure of 1.1 mm Hg at 25 °C(1), indene is expected to exist almost entirely in the vapor phase in the ambient atmosphere(2,SRC). Vapor-phase indene will degrade rapidly in the ambient atmosphere by reaction with photochemically produced hydroxyl radicals with an estimated half-life of about 6.2 hours(3,SRC).
Food Survey ValuesIndene was qualitatively identified as a volatile component of roasted filberts(1).
Adverse EffectsOccupational hepatotoxin - Secondary hepatotoxins: the potential for toxic effect in the occupational setting is based on cases of poisoning by human ingestion or animal experimentation.
Exposure Routesinhalation, ingestion, skin and/or eye contact
Signs and SymptomsIn Animals: irritation eyes, skin, mucous membrane; dermatitis, skin sensitization; chemical pneumonitis (aspiration liquid); liver, kidney, spleen injury
Effluent Concentrations
Indene was qualitatively identified in effluents from a POTW facility in Sauget, Illinois(1). On October 24, 1974, indene was qualitatively found in advanced waste treatment concentrates from Lake Tahoe, CA(2). During August and September of 1979, indene was found at a concn range of 0.08-0.4 ug/cu-m in the Allegheny Mountain Tunnel in Pennsylvania(3). Indene was identified at a concn range of 10.3-137.6 ng/L in paper-mill effluents being discharged into the Rainy River(4). Indene was identified in a plume of contaminated water moving through sand away from creosote waste disposal lagoons(5). Indene was found at a concn of 1.28 in an air sample taken near an oil fire(6).
Indene was found in a groundwater sample prior to coal gasification (0.03 ppm), process water during gasification (272 and 72 ppm), and aqueous condensate from low-BTU coal gasification (363 ppm)(1). Indene was found at a concn of 15 ng/L in a canal to a harbor of a freshwater lake before any boat traffic was observed; after 1,293 boats passed through the canal, the concn of indene was 74 ng/L(2). Indene has been detected in wastewater effluents from the timber products industry at a concn of 8,252 ng/ul extract(3).
Soil Adsorption/MobilityBased on a measured log Kow of 2.92(2) and a regression derived equation(1), the Koc for indene can be estimated to be about 540(SRC). According to a suggested classification scheme(3), this Koc value suggests low mobility in soil.
Natural Pollution SourcesIndene is found in high-temperature coal tar at an average concn of 1 percent(1). It can be released to the environment in emissions from biomass combustion(2).
Atmospheric Concentrations
In 1977, indene was qualitatively identified in the air of six industrial cities of the former USSR(1). Indene was qualitatively found in the air of three South African cities during the summer of 1975-winter of 1976(2). Indene was qualitatively identified in air taken at Homebush Bay, Australia on June 3, 1975(3). Indene was qualitatively identified in Paris air on October 24, 1972(4).
Human Toxicity Excerpts
BY ANALOGY BETWEEN CHEMICAL STRUCTURE & TOXICOLOGICAL EFFECTS OF RELATED MONOAROMATIC HYDROCARBONS, INHALATION OF INDENE VAPORS CAN BE EXPECTED TO CAUSE IRRITATION OF MUCOUS MEMBRANES.
THERE ARE ... SENSITIZING ACTIONS OF COUMARONE & INDENE, USED IN COPOLYMERIZATION WHEN MAKING COUMARONE-INDENE RESINS. USE OF THESE RESINS CONTAMINATED WITH TRACES OF MONOMERS CAN CAUSE ALLERGIC DERMATITIS.
Safety data
- F
- 8
- OEB
- A
- OEL
- TWA: 10 ppm (45 mg/m3)
- PPE
- Eyeshields, Faceshields, Gloves, type ABEK (EN14387) respirator filter
- wgk
- 1
- tsca
- TSCA listed
- rtecs
- NK8225000
- ridadr
- UN 3295 3/PG 3
- hs_code
- 2902 90 00
- risk_code
- 10-65-36/37/38-20
- Signal word
- Danger
- Symbol(GHS)
- GHS02,GHS08
- hazard_code
- Xn
- safety_code
- 23-24/25-62-37/39-26
- hazard_class
- 3
- Storage Class
- 3 - Flammable liquids
- packing_group
- III
- Hazard statements
- H226-H304
- Limited Quantities
- 5.0 L (1.3 gallons) (liquid)
- Excepted Quantities
- Max Inner Pack (30g or 30ml) and Max Outer Pack (1Kg or 1L)
- REACH Registrations
- Active
- Hazard Classifications
- Asp. Tox. 1Flam. Liq. 3
- Precautionary statements
- P210-P233-P240-P241-P301+P310-P331
- Hazardous Substances Data
- 95-13-6(Hazardous Substances Data)
Chemistry & industry
Pharmacology
Metabolism/Metabolites
YIELDS CIS-1,2-DIHYDROXYINDANE & TRANS-1,2-DIHYDROXYINDANE IN RABBITS. /FROM TABLE/
RAT-LIVER MICROSOMES SUPPLEMENTED WITH NADPH CONVERTED INDENE INTO TRANS-INDANE-1,2-DIOL ...
THE OXIDATION OF INDENE TO TRANS-1,2-DIHYDROXYINDANE IN LIVER PREPN IN VITRO WAS DEMONSTRATED. THE REACTION WAS MEDIATED BY LIVER MICROSOMES OF RATS & RABBITS IN THE PRESENCE OF NADPH-GENERATING SYSTEMS.
Uses & manufacturing
Uses
Used to prepare coumarone-indene resins; [ACGIH]
Plastic Composites Manufacturing [Category: Industry]
Used as a comonomer in coumarone and petroleum-derived aromatic hydrocarbon resins. Technical pure indene is used for the production of indan and its derivatives. Esters of indene-1-carboxylic acid, which are effective as acaricides, can be synthesized from indene for use in, eg, collars
It is composed of a benzene ring fused with a cyclopentene ring.
U.S. Production2023: 500,000 - <1,000,000 lb
Industry UsesMonomers
Methods of Manufacturing
... FROM ACETYLENE OVER ACTIVATED CHARCOAL @ 625 °C ... MFR FROM TETRAHYDRONAPHTHALENE BY PASSING OVER SIO2-AL2O3 CATALYST @ 670 °C
Pyrolysis residual oils from olefin production contain varying amounts of indene, which can be separated by extractive distillation with N-methyl-2- pyrrolidone or by crystallization. Indene is recovered industrially from dephenolated and debased tar light oil by rectifying distillation followed by crystallization. When the phenol extraction is omitted a highly concentrated indene fraction can also be obtained by azeotropic distillation of an indene- phenol fraction with water, whereby the phenol is separated as a bottom product.
Use ClassificationFragrance Ingredients
General Manufacturing Information
Petrochemical Manufacturing
1H-Indene: ACTIVE
Applications
DescriptionIndene (also called 1H-Indene, C9H8) is a flammable polycyclic hydrocarbon. It is a colorless and aromatic smelling liquid. It is used in the synthesis of new C60 derivative (indene-C60 Bisadduct) and to prepare polyindene by the controlled cationic polymerization initiated with cumyl methyl ether/TiCl4 in CH2Cl2. Polyindene is further used to synthesize polyolefins. Indene is also used in the synthesis of istatins, in the production of indene/cumarone thermoplastic resins, and in the production of hydrocarbon resins. These industrial resins, also called indene-coumarone resins, are mainly consumed by the paints & coatings, rubber, and construction industries. It should be stored in a cool place. The container should be kept tightly closed in a dry and well-ventilated place. Containers which areopened must be carefully resealed and kept upright to prevent leakage. Indene is incompatible with strong oxidizing agents. Recommended storage temperature is 2 - 8°C. Indene is sensitive to light.
UsesPreparation of coumarone-indene resins, intermediate.
UsesPreparation of coumarone-indene resins
Uses1H-Indene is a building block that has been used in the synthesis of isatins. It was used in the synthesis of new C60 derivative, indene-C60 bisadduct. It was used in preparing polyindene by the controlled cationic polymerization initiated with cumyl methyl ether/TiCl4 in CH2Cl2.
General DescriptionA colorless liquid derived from coal tar. Fp: -2°C; bp:182°C. Density 0.997 g cm-3. Insoluble in water but soluble in organic solvents.
Upstream & downstream products
Upstream raw materials
Downstream products
Additional notes
Definitionindene: A colourless flammable hydrocarbon,C9H8; r.d. 0.996; m.p.–1.8°C; b.p. 182.6°C. Indene is anaromatic hydrocarbon with a five-memberedring fused to a benzenering. It is present in coal tar and isused as a solvent and raw materialfor making other organic compounds.
Related reactions
215 records
Linked notes
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