Definition
Morpholine is an organic heteromonocyclic compound whose six-membered ring contains four carbon atoms and one nitrogen atom and one oxygen atom that lies opposite to each other; the parent compound of the morpholine family. It is a saturated organic heteromonocyclic parent and a member of morpholines. It is a conjugate base of a morpholinium.
Source: PubChem
US FDA substance register · UNII 8B2ZCK305O · registered name Morpholine · single chemical substance
Cosmetic roles
Safety & regulatory references
- Banned
- Argentina · ASEAN · Brazil · Canada · China · European Union · South Korea · United Kingdom
Source: ASEAN Cosmetic Directive · EU Cosmetics Regulation · Health Canada Cosmetic Ingredient Hotlist · MFDS (Korea) cosmetic regulatory information · UK cosmetics regulations (OPSS)
Not classified under Korea’s toxic-substance GHS list · existing chemical substance
EU Cosmetics Regulation, Annex II (prohibited substances), entry 344
Health Canada Cosmetic Ingredient Hotlist · prohibited in cosmetics
Restriction II/344
Source: EU CosIng ingredient list
Reviewed by CIR: Final Report on the Safety Assessment of Morpholine
CIR reviewed this ingredient and flagged its status as: CIR insufficient data ingredients - use not supported (insufficient data or use not supported — CIR's own classification, not a full safety-as-used conclusion).
More data — names, identifiers, properties, test records, literature
Official labels & definitions
JCIA labelling name モルホリン: 本品は、次の化学式で表される複素環式化合物である。
Source: JCIA labelling names (Japan)
Names & identifiers
- CAS No.chemical registry number
- 110-91-8
- EC No.EU chemical inventory number
- 203-815-1
- DTXSIDUS EPA chemical ID
- DTXSID2025688
- DTXCIDUS EPA compound ID
- DTXCID305688
- IUPAC
- Morpholine
- Molecular formula
- C4H9NO
- Molecular weight
- 87.122 g/mol
Measured properties
- Colour
- colourless
- pH
- 11
- Melting/freezing point
- -4.8 ℃
- Initial boiling point and range
- 128 ℃
- Flash point
- 32 ℃(1 013.25 hPa)
- Evaporation rate
- 1
- Upper/lower flammability or explosive limits
- 11.2 / 1.4 %
- Vapour pressure
- 10.1 ㎜Hg (25℃)
- Water solubility
- 1.00X10+6 ㎎/ℓ
- Vapour density
- 3
- Relative density
- 1.007 (20℃)
- n-Octanol/water partition coefficient (Kow)
- -0.86
- Auto-ignition temperature
- 310 ℃
- Viscosity
- 2.23 (20℃)
- Molecular weight
- 87.12
Values measured on the substance itself. The KOSHA data are a reference for writing and reviewing safety data sheets, not a specification for a commercial raw material.
Source: KOSHA safety data sheets (Korea)
What products actually use it for
What the 47 products reported to the US EPA with this ingredient use it for. Products outside cosmetics are included, so the top few rows are its main uses.
- Chelating agent19
- pH regulating agent14
- Corrosion inhibitor5
- Solvent3
- Processing aids not otherwise specified3
- Intermediate2
- Brightener1
Source: US EPA CompTox dashboard
Irritation and sensitisation studies
8 skin studies and 5 eye studies are on record.
The study conclusions largely agree (100%). These tests are on the raw material itself; irritation at the amount in a finished product is a different question.
See all 13 studies
- Category 8.2A (Category 1A)
Skin Irritation · Read Across - Corrosive
skin irritation: in vivo · Screening · OECD Guideline 404 (Acute Dermal Irritation / Corrosion) according to - Category 1
Skin Irritation · Screening - Classification not possible
Skin Sensitization · Screening - Severe Irritation
skin irritation: in vivo · Screening · OECD Guideline 404 (Acute Dermal Irritation / Corrosion) according to - Skin Corr. 1B
Skin Irritation · Authoritative - Skin Corr. 1B
Skin Irritation · Screening - Skin corrosion/irritation - Category 1
Skin Irritation · Screening - Category 8.3A (Category 1)
Eye Irritation · Read Across - Category 1
Eye Irritation · Screening - Corrosive or Irritation Persists for > 21 days
eye irritation: in vivo · Screening · OECD Guideline 405 (Acute Eye Irritation / Corrosion) according to - Corrosive or Irritation Persists for > 21 days
eye irritation: in vivo · Screening · OECD Guideline 405 (Acute Eye Irritation / Corrosion) equivalent or similar to - Eye Dam. 1
Eye Irritation · Screening
Source: US EPA CompTox dashboard
Related literature
- Network-based exploration of 4-(phenylsulfonyl)morpholine molecules for metastatic triple-negative breast cancer suppression · 2026
- Exploring Antiproliferative Potential, In Silico Docking, and Molecular Dynamics of Pyrimidine-Morpholine Hybrid Molecules · 2025
- Synthesis of 4‐Azaindole‐morpholine‐1,3,4‐oxadiazole Conjugates as Epidermal Growth Factor Receptor Inhibitors · 2022
- Study of mutagenic effects with predicted carcinogenicity of 4-((5-decylthio)-4-methyl-4-H-1,2,4-triazole-3-yl)methyl)morpholine for further research in order to create a new drug with antifungal activity · 2022
- INFLUENCE OF MORPHOLINE ON CHANGES IN KIDNEY TISSUE AND WHITE BLOOD CELLS OF NMRI MALE ALBINO MICE · 2014
Linked databases 25
- ASEAN Cosmetic Directive
- Australian Industrial Chemicals Inventory (AICIS)
- ChEBI
- ChEMBL
- EU CosIng ingredient list 2
- EU Cosmetics Regulation
- EU prohibited substances (Annex II)
- Health Canada Cosmetic Ingredient Hotlist
- IARC carcinogen classification
- JCIA labelling names (Japan)
- Korea toxic substances GHS register (NIER)
- KOSHA safety data sheets (Korea)
- MFDS (Korea) cosmetic regulatory information 2 3
- NIST Chemistry WebBook
- PubChem
- Tlooto literature search 2 3 4 5
- UK cosmetics regulations (OPSS)
- UniChem cross-reference IDs
- US Cosmetic Ingredient Review (CIR) 2 3
- US EPA CompTox dashboard 2
- US EPA DSSTox chemical database
- US FDA substance registration (GSRS)
- US FDA Unique Ingredient Identifier (UNII)
- Wikidata
- Wikipedia · English · Japanese · Chinese