Provenance

Reference data from EU CLP Annex VI and published regulations — verify against your supplier's SDS before use.

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Substance profile

3,5,5-trimethylcyclohex-2-enone

3,5,5-trimethylcyclohex-2-enone is a water-white liquid with a peppermint-like odor.

CAS 78-59-1 Warning

01 · Identification

What 3,5,5-trimethylcyclohex-2-enon… is

3,5,5-trimethylcyclohex-2-enone is a water-white liquid with a peppermint-like odor. It boils at 215 °C, melts at -8.1 °C, is soluble in water.

Under the GHS it carries the signal word Warning. It is classed as hazardous Air Pollutants (HAPs).

02 · Identifiers

3,5,5-trimethylcyclohex-2-enon… identifiers and molecular data

3,5,5-trimethylcyclohex-2-enon… CAS number and EC number

CAS number78-59-1
EC number201-126-0
Index number (CLP Annex VI)606-012-00-8

3,5,5-trimethylcyclohex-2-enon… molecular formula and molecular weight

Chemical class Hazardous Air Pollutants (HAPs)

Other names for 3,5,5-trimethylcyclohex-2-enon…

  • isophorone

03 · GHS classification

3,5,5-trimethylcyclohex-2-enon… hazard classification

Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.

3,5,5-trimethylcyclohex-2-enon… pictograms and signal word

Signal wordWarning

3,5,5-trimethylcyclohex-2-enon… hazard class and category

GHS hazard classes 3,5,5-trimethylcyclohex-2… falls into
Hazard class Category From code Pictogram
Acute toxicity - oral GHS chapter 3.1 Category 4 H302 GHS07
Acute toxicity - dermal GHS chapter 3.1 Category 4 H312 GHS07
Serious eye damage/eye irritation GHS chapter 3.3 Category 2A H319 GHS07
Carcinogenicity GHS chapter 3.6 Category 2 H351 GHS08
Specific target organ toxicity - single exposure GHS chapter 3.8 Category 3 H335 GHS07

3,5,5-trimethylcyclohex-2-enon… hazard statements (H-codes)

Hazard statements assigned to 3,5,5-trimethylcyclohex-2…
CodeHazard statement
H351 Suspected of causing cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
H312 Harmful in contact with skin.
H302 Harmful if swallowed.
H335 May cause respiratory irritation.
H319 Causes serious eye irritation.

This page lists only the codes assigned to 3,5,5-trimethylcyclohex-2…. The full reference lives on the hazard statements hub, the precautionary statements hub and the GHS pictograms hub.

Safety Data Sheet

Getting an SDS for 3,5,5-trimethylcyclohex-2…

A Safety Data Sheet is written for a product, not for a substance: the supplier of the grade you actually buy issues it, so two suppliers of 3,5,5-trimethylcyclohe… issue two different sheets. That is why there is no single authoritative SDS for a substance to download — what there is, is the job of collecting the sheets for the products you hold and keeping them current as suppliers revise them.

04 · Precautionary statements

3,5,5-trimethylcyclohex-2-enon… precautionary statements

CLP Annex VI assigns 14 precautionary statements to 3,5,5-trimethylcyclohex-2…. They are grouped the way a label groups them: what to do before handling, what to do when something has already happened, how to store it and how to dispose of it.

Reading the notation. is a blank the supplier fills in — not a truncated sentence.· [square brackets] mark a part printed only when it applies.

05 · Names in the regulation

3,5,5-trimethylcyclohex-2-enon… name in 23 EU languages

CLP Annex VI Part 3 is published in every language edition of the regulation, and the identification column is written out in each of them. Nothing below is translated by us: each line is the name as that edition prints it. Under Art. 18(2) the substance name from Annex VI is a lawful product identifier, so this is the wording to put on a label going to that market — and where the cell lists several designations, any one of them qualifies.

Language Name in CLP Annex VI Part 3
Bulgarian български 3,5,5-триметилциклохекс-2-енон изофорон
Spanish español 3,5,5-Trimetilciclohex-2-enona isoforona
Czech čeština 3,5,5-trimethylcyklohex-2-en-1-on isoforon
Danish dansk 3,5,5-trimethylcyclohex-2-enon isophoron
German Deutsch 3,5,5-Trimethylcyclohex-2-enon Isophoron3,5,5-Trimethylcyclohex-2-en-1-on
Estonian eesti 3,5,5-trimetüültsükloheks-2-enoon isoforoon
Greek ελληνικά 3,5,5-τριμεθυλοκυκλοεξ-2-ενόνη ισοφορόνη
English English 3,5,5-trimethylcyclohex-2-enone isophorone
French français 3,5,5-triméthylcyclohex-2-énone isophorone
Croatian hrvatski 3,5,5-trimetilcikloheks-2-enon izoforon
Italian italiano 3,5,5-trimetilcicloes-2-enone isoforone
Latvian latviešu 3,5,5-trimetilcikloheks-2-enons izoforons
Lithuanian lietuvių 3,5,5-trimetil-2-cikloheksen-1-onas izoforonas
Hungarian magyar 3,5,5-trimetilciklohex-2-enon izoforon
Maltese Malti 3,5,5-trimetilċikloeż-2-enon isoforon
Dutch Nederlands 3,5,5-trimethylcyclohex-2-enon isoforon
Polish polski 3,5,5-trimetylocykloheks-2-en-1-on izoforon
Portuguese português 3,5,5-trimetil-2-ciclo-hexen-1-ona isoforona
Romanian română 3,5,5-trimetilciclohexen-2-onă izoforonă
Slovak slovenčina 3,5,5-trimetylcyklohex-2-enón izoforón
Slovenian slovenščina 3,5,5-trimetilcikloheks-2-enon izoforon
Finnish suomi 3,5,5-trimetyylisykloheks-2-enoni isoforoni
Swedish svenska 3,5,5-trimetylcyklohex-2-enon isoforon

All 23 language editions of Annex VI carry this entry. Irish is the twenty-fourth official EU language and has no line here for a different reason: no consolidated CLP text has ever been published in Irish, so there is no Irish edition of Annex VI to quote a name from. Source: consolidated CLP, CELEX 02008R1272, language editions. © European Union, https://eur-lex.europa.eu — only the electronic Official Journal of the European Union is authentic.

06 · Label elements

3,5,5-trimethylcyclohex-2-enon… GHS label elements

Everything CLP Annex VI fixes for 3,5,5-trimethylcyclohex-2…, laid out the way it appears on a label. The greyed lines are the parts only the supplier can fill in.

GHS08 Health hazard pictogramGHS07 Exclamation mark pictogram

Warning

3,5,5-trimethylcyclohex-2-enon…

  • Suspected of causing cancer <state route of exposure if it is conclusively proven that no other routes of exposure cause the hazard>.
  • Harmful in contact with skin.
  • Harmful if swallowed.
  • May cause respiratory irritation.
  • Causes serious eye irritation.
  • Obtain special instructions before use.
  • Wash thoroughly after handling.
  • Do not eat, drink or smoke when using this product.
  • Wear protective gloves/protective clothing/eye protection/face protection/hearing protection/
  • IF SWALLOWED:
  • IF ON SKIN:
  • IF IN EYES:
  • IF exposed or concerned:
  • Call a POISON CENTER/doctor/ if you feel unwell.
  • Get medical advice/attention.
  • Rinse mouth.
  • If eye irritation persists:
  • Remove contact lenses, if present and easy to do. Continue rinsing.
  • Wash with plenty of water/

Supplier name, address and telephone number· Product identifier·Nominal quantity

Need this as an actual label? Open 3,5,5-trimethylcyclohex-2… in the GHS label constructor →

07 · Health hazards

3,5,5-trimethylcyclohex-2-enon… health hazards and exposure limits

3,5,5-trimethylcyclohex-2-enon… hazard summary

Isophorone is a clear liquid that smells like peppermint. It can be dissolved in water and evaporates somewhat faster than water. It is an industrial chemical used as a solvent in some printing inks, paints, lacquers, and adhesives. It is also used as an intermediate in the production of certain chemicals. Although isophorone is an industrial chemical, it also occurs naturally in cranberries.

Source: Agency for Toxic Substances and Disease Registry (ATSDR)

3,5,5-trimethylcyclohex-2-enon… carcinogenicity classification

IARC classification Group 2B — Possibly carcinogenic to humans
IARC monographs Volume 130: (2022) 1,1,1-Trichloroethane and Four Other Industrial Chemicals

Under the conditions of these 2-year gavage studies, there was some evidence of carcinogenicity of isophorone in male F344/N rats as shown by the occurrence of renal tubular cell adenomas and adenocarcinomas in animals given 250 or 500 mg/kg per day; carcinomas of the preputial gland were also observed at increased incidence in male rats given 500 mg/kg. There was no evidence of carcinogenicity in female F344/N rats given 250 or 500 mg/kg per day. For male B6C3F1 mice, there was equivocal evidence of carcinogenicity of isophorone as shown by an increased incidence of hepatocellular adenomas or carcinomas (combined) and of mesenchymal tumors in the integumentary system in animals given 500 mg/kg per day and by an increase in malignant lymphomas in animals given 250 mg/kg per day. There was no evidence of carcinogenicity of isophorone in female B6C3F1 mice given 250 or 500 mg/kg per day.

Source: US National Toxicology Program · TR-291: Toxicology and Carcinogenesis Studies of Isophorone (CASRN 78-59-1) in F344/N Rats and B6C3F1 Mice (Gavage Studies) (1986 )

Cancer Classification: Group C Possible Human Carcinogen

Source: Hazardous Substances Data Bank (HSDB)

CLASSIFICATION: C; possible human carcinogen. BASIS FOR CLASSIFICATION: Based on no data in humans; limited evidence of carcinogenicity of one tumor type in one sex of one animal species as shown by an increase of preputial gland carcinomas in male rats. The apparent renal tubular cell tumor in the male rat is associated with alpha-2u-globulin, considered to be of questionable relevance to humans. HUMAN CARCINOGENICITY DATA: None. ANIMAL CARCINOGENICITY DATA: Limited.

Source: Hazardous Substances Data Bank (HSDB)

An IARC group and a CLP classification answer different questions. IARC judges whether the evidence for cancer in humans is strong enough; CLP Annex VI is the legally binding EU classification. A substance can carry one and not the other.

3,5,5-trimethylcyclohex-2-enon… occupational exposure limits

US occupational exposure limits reported for 3,5,5-trimethylcyclohex-2…. PEL is enforceable (OSHA), REL is a recommendation (NIOSH), IDLH is the concentration at which escape becomes impossible without injury.
Limit Value Source
PEL 25.0 [ppm] Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
PEL 25 ppm (140 mg/m³) Occupational Safety and Health Administration (OSHA)
PEL TWA 25 ppm (140 mg/m3) See Appendix G The National Institute for Occupational Safety and Health (NIOSH)
REL 4 ppm (23 mg/m³) Occupational Safety and Health Administration (OSHA)
REL TWA 4 ppm (23 mg/m3) The National Institute for Occupational Safety and Health (NIOSH)
IDLH 200 ppm (NIOSH, 2024) CAMEO Chemicals
IDLH 200.0 [ppm] Haz-Map, Information on Hazardous Chemicals and Occupational Diseases
IDLH 200 ppm Hazardous Substances Data Bank (HSDB)

These are United States values. The European Union sets its own indicative and binding limits, and the figure that applies at a given workplace is the one in the local regulation — not the one shown here.

08 · Physical and chemical properties

3,5,5-trimethylcyclohex-2-enon… properties

Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.

3,5,5-trimethylcyclohex-2-enon… boiling point

Property Value Conditions Source
Boiling point 215.32 °C (419.6 °F) HSDB
215 °C (419 °F) NIOSH
215.22 °C (419.4 °F) at 760 mmHg CAMEO

3,5,5-trimethylcyclohex-2-enon… melting point

Property Value Conditions Source
Melting point -8.1 °C (17.4 °F) HSDB
-8.33 °C (17 °F) NIOSH
-7.78 °C (18 °F) CAMEO

3,5,5-trimethylcyclohex-2-enon… density

Property Value Conditions Source
Density 0.92 g/cm³ NIOSH
0.9255 g/cm³ at 20 °C HSDB
0.9227 g/cm³ at 20 °C HSDB

3,5,5-trimethylcyclohex-2-enon… solubility

Property Value Conditions Source
Solubility Soluble in ether, acetone, alcohol HSDB
Has high solvent power for vinyl resins, cellulose esters, ether, and many substances soluble with difficulty in other solvents. HSDB
In water, 12,000 mg/l @ 25 °C. at 25 °C HSDB

3,5,5-trimethylcyclohex-2-enon… vapor pressure

Property Value Conditions Source
Vapor pressure 0.3 mmHg NIOSH
0.2 mmHg at 20 °C CAMEO
0.438 mmHg at 25 °C HSDB

3,5,5-trimethylcyclohex-2-enon… flash point

Property Value Conditions Source
Flash point 84.44 °C (184 °F) HSDB

3,5,5-trimethylcyclohex-2-enon… autoignition temperature

Property Value Conditions Source
Autoignition temperature 460 °C (860 °F) HSDB
462.22 °C (864 °F) CAMEO

3,5,5-trimethylcyclohex-2-enon… lower explosive limit (LEL)

Property Value Conditions Source
Lower explosive limit (LEL) 0.8 % by volume HSDB

3,5,5-trimethylcyclohex-2-enon… upper explosive limit (UEL)

Property Value Conditions Source
Upper explosive limit (UEL) 3.8 % by volume HSDB

3,5,5-trimethylcyclohex-2-enon… vapor density

Property Value Conditions Source
Vapor density 4.77 (air = 1) HSDB
4.8 (air = 1) ICSC

3,5,5-trimethylcyclohex-2-enon… odor threshold

Property Value Conditions Source
Odor threshold Odor detection in air= 2.00 ppm. Purity not specified. HSDB
Odor recognition in air= 5.40 ppm. Purity not specified. HSDB
1 mg/cu m (odor low); 50 mg/cu m (odor high) HSDB

Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.

09 · Fire and explosion

3,5,5-trimethylcyclohex-2… fire and explosion behaviour

These are descriptions rather than measured values, so they are kept out of the table above and quoted here with the source that reported them.

3,5,5-trimethylcyclohex-2-enon… fire potential

Flammable & explosive when exposed to heat or flame.

Source: Hazardous Substances Data Bank (HSDB)

10 · Handling and storage

3,5,5-trimethylcyclohex-2-enon… storage and handling

3,5,5-trimethylcyclohex-2-enon… peroxide formation

D: Other compounds that may form peroxides

Source: Lab and Research Safety, University of Minnesota

3,5,5-trimethylcyclohex-2-enon… safe storage

Separated from strong oxidants, strong bases and amines.

Source: ILO-WHO International Chemical Safety Cards (ICSCs)

3,5,5-trimethylcyclohex-2-enon… storage conditions

store in a cool, dry, well-ventilated location. Outside or detached storage is preferred. Separate from oxidizing materials.

Source: Hazardous Substances Data Bank (HSDB)

3,5,5-trimethylcyclohex-2-enon… incompatible materials

Incompatible with strong oxidizers

Source: Hazardous Substances Data Bank (HSDB)

3,5,5-trimethylcyclohex-2-enon… reactivity

Ketones, such as ISOPHORONE, are reactive with many acids and bases liberating heat and flammable gases (e.g., H2). The amount of heat may be sufficient to start a fire in the unreacted portion of the ketone. Ketones react with reducing agents such as hydrides, alkali metals, and nitrides to produce flammable gas (H2) and heat. Ketones are incompatible with isocyanates, aldehydes, cyanides, peroxides, and anhydrides. They react violently with aldehydes, HNO3, HNO3 + H2O2, and HClO4. Forms explosive peroxides

Source: CAMEO Chemicals

Planning storage for a mix of chemicals? Check 3,5,5-trimethylcyclohex-2… in the storage compatibility matrix →

11 · Questions

3,5,5-trimethylcyclohex-2-enon… — frequently asked questions

What is the CAS number of 3,5,5-trimethylcyclohex-2-enon…?

The CAS number of 3,5,5-trimethylcyclohex-2-enon… is 78-59-1. Its EC number is 201-126-0.

What does a 3,5,5-trimethylcyclohex-2-enon… label have to show?

Under CLP Annex VI the label for 3,5,5-trimethylcyclohex-2-enon… carries the pictograms Health hazard and Exclamation mark and the signal word is Warning.

Is 3,5,5-trimethylcyclohex-2-enon… flammable?

CLP Annex VI assigns 3,5,5-trimethylcyclohex-2-enon… no flammability hazard class. That is not a statement that it cannot burn: the harmonised list only records the hazards that were assessed for it. The flash point reported for it is 84.44 °C (184 °F) (HSDB).

Is 3,5,5-trimethylcyclohex-2-enon… a carcinogen?

CLP Annex VI assigns 3,5,5-trimethylcyclohex-2-enon… H351 — suspected of causing cancer. That is category 2: the evidence points that way but is not conclusive. IARC places it in Group 2B: possibly carcinogenic to humans.

What is the exposure limit for 3,5,5-trimethylcyclohex-2-enon…?

The US occupational exposure limit reported for 3,5,5-trimethylcyclohex-2-enon… is 25.0 [ppm] (Haz-Map, Information on Hazardous Chemicals and Occupational Diseases). Limits differ by country: the EU sets its own indicative and binding values, and the figure that applies at a given workplace is the one in the local regulation.

What is the boiling point of 3,5,5-trimethylcyclohex-2-enon…?

The boiling point reported for 3,5,5-trimethylcyclohex-2-enon… is 215.32 °C (419.6 °F) (HSDB).

What is the melting point of 3,5,5-trimethylcyclohex-2-enon…?

The melting point reported for 3,5,5-trimethylcyclohex-2-enon… is -8.1 °C (17.4 °F) (HSDB).

How should 3,5,5-trimethylcyclohex-2-enon… be stored?

store in a cool, dry, well-ventilated location. Outside or detached storage is preferred. Separate from oxidizing materials. (Hazardous Substances Data Bank (HSDB))

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