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Methylparaben

Athanor · official

C8H8O3 · 152.15 g/mol

IUPAC name: methyl 4-hydroxybenzoate

Also called paraben, methyl 4-hydroxybenzoate, E218, Nipagin

ReagentsRings
Open in Athanor
The structure of Methylparaben
Drawn from its SMILES with RDKit
Harmful or irritantWarningCauses skin irritation · Causes serious eye irritation · May cause respiratory irritation

Names and identifiers

IUPAC name
methyl 4-hydroxybenzoate
Synonyms
paraben, methyl 4-hydroxybenzoate, E218
+ 38 more

Nipagin, Methyl 4-hydroxybenzoate, Methyl paraben, Methyl p-hydroxybenzoate, Tegosept M, Moldex, Maseptol, Methyl parahydroxybenzoate, p-Hydroxybenzoic acid methyl ester, Preserval M, Preserval, Metaben, Methaben, Metoxyde, Paridol, Solbrol, Septos, Methyl parasept, 4-Hydroxybenzoic acid methyl ester, Methyl butex, Methyl chemosept, p-Methoxycarbonylphenol, p-Carbomethoxyphenol, Nipagin M, Benzoic acid, 4-hydroxy-, methyl ester, Methylben, Abiol, Solbrol M, Methyl-p-hydroxybenzoate, Aseptoform, Methyl p-oxybenzoate, 4-(Methoxycarbonyl)phenol, FEMA No. 2710, p-Hydroxybenzoic methyl ester, p-Oxybenzoesauremethylester, Methyl ester of p-hydroxybenzoic acid, Killitol, Benzoic acid, p-hydroxy-, methyl ester

Molecular formula
C8H8O3
Empirical formula
C8H8O3
Molecular weight
152.15 g/mol
Exact mass
152.04734
CAS number
99-76-3
PubChem CID
7456
Canonical SMILES
COC(=O)C1=CC=C(C=C1)O
Isomeric SMILES
COC(=O)C1=CC=C(C=C1)O
InChI
InChI=1S/C8H8O3/c1-11-8(10)6-2-4-7(9)5-3-6/h2-5,9H,1H3
InChIKey
LXCFILQKKLGQFO-UHFFFAOYSA-N
Molfile

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

Physical properties

Appearance
Colorless crystals or white crystalline powder[2]
2 values

From Hazardous Substances Data Bank (HSDB), the most authoritative source here.

ValueAs writtenSource
–Dry Powder; Other Solid; Liquid; Wet Solid; Other Solid[1] EPA Chemical Data Reporting (CDR)
–shownColorless crystals or white crystalline powder[2] Hazardous Substances Data Bank (HSDB)cites Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 10th ed. Volumes 1-3 New York, NY: John Wiley & Sons Inc., 1999., p. V3: 2013
Odor
Odorless or has faint characteristic odor[2]
Solubility in water
In water, 2.50 × 10³ mg/L at 25 °C[2]
2 values

From Hazardous Substances Data Bank (HSDB), the most authoritative source here.

ValueAs writtenSource
–shownIn water, 2.50X10+3 mg/L at 25 °C[2] Hazardous Substances Data Bank (HSDB)cites Yalkowsky, S.H., He, Yan, Jain, P. Handbook of Aqueous Solubility Data Second Edition. CRC Press, Boca Raton, FL 2010, p. 481
–For more Solubility (Complete) data for METHYLPARABEN (6 total), please visit the HSDB record page.[2] Hazardous Substances Data Bank (HSDB)
log P
log Kow = 1.96[2]

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
11
Rings
1
Aromatic rings
1
Fraction sp³ carbons (Fsp3)
0.12
H-bond donors
1
H-bond acceptors
3
Rotatable bonds
1 computed here · PubChem 2
TPSA (Ų)
46.5
Formal charge
0
XLogP3
2 PubChem
Complexity
136 PubChem
Stereocenters
None
Double-bond geometry
None specified
Point group
Cs of one 3D conformer with its hydrogens, by Athanor’s engine (as in the app)

Elemental analysis

  • C63.15%
  • H5.30%
  • O31.55%

Isotope pattern

100%152.0478.9%153.051154.053

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
1.18 Crippen (Wildman and Crippen 1999)
log S (water solubility)
-1.86 ESOL (Delaney 2004), log mol/L
Synthetic accessibility
1.39 SA score, 1 easy to 10 hard (Ertl and Schuffenhauer 2009)

Drug-likeness: Lipinski’s rule of five

  • Molecular weight ≤ 500: 152.15
  • log P ≤ 5 (Crippen): 1.18
  • H-bond donors ≤ 5: 1
  • H-bond acceptors ≤ 10: 3

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: 3,282 company reports to ECHA. Source [3].

  • Harmful or irritant
  • H315Causes skin irritation (53.8% of reports)
  • H319Causes serious eye irritation (53.7% of reports)
  • H335May cause respiratory irritation (50.5% of reports)

Precautionary statements: P261, P264, P264+P265, P271, P280, P302+P352, P304+P340, P305+P351+P338, P319, P321, P332+P317, P337+P317, P362+P364, P403+P233, P405, P501

View all classifications (3)
  • [3] European Chemicals Agency (ECHA)This chemical does not meet GHS hazard criteria for 31.5% (1035 of 3282) of reports.
  • [3] European Chemicals Agency (ECHA) · 3,282 reports · WarningH315, H319, H335
  • [2] Hazardous Substances Data Bank (HSDB)H402, H412

Storage

  • Keep container tightly closed in a dry and well-ventilated place.[2]

Incompatibilities

  • Incompatible materials: Strong oxidizing agents, strong bases[2]

Safety data sheets on the supplier’s page: Finetech Industry Limited, LGC Standards, Clearsynth.

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. [1]EPA Chemical Data Reporting (CDR) · Public domain (US EPA) · via PubChem · retrieved 2026-10-14
  2. [2]Hazardous Substances Data Bank (HSDB) · Public domain (US NLM) · via PubChem · retrieved 2026-10-14
  3. [3]European Chemicals Agency (ECHA) · ECHA legal notice: reuse with acknowledgement · via PubChem · retrieved 2026-10-14
  4. [4]NMRShiftDB · Linked only · via PubChem · retrieved 2026-10-14
  5. [5]Human Metabolome Database (HMDB) · Linked only · via PubChem · retrieved 2026-10-14
  6. [6]SpectraBase · Linked only · via PubChem · retrieved 2026-10-14
  7. [7]MassBank Europe · Linked only · via PubChem · retrieved 2026-10-14
  8. [8]MassBank of North America (MoNA) · CC BY 4.0 · via PubChem · retrieved 2026-10-14
  9. [9]NIST Mass Spectrometry Data Center · Linked only · via PubChem · retrieved 2026-10-14
  10. ·Calculated values: computed by Athanor with RDKit 2026.09 from the structure.
  11. ·Literature on PubChem

Data last updated 2026-10-14.