undefined 1
undefined 2
p-Hydroxyanisole
AKA “4-Methoxyphenol, Mequinol, 150-76-5, 4-Hydroxyanisole, p-Methoxyphenol, Phenol, 4-methoxy-, HYDROQUINONE MONOMETHYL ETHER, MEHQ, Leucobasal”
Antioxidant
Ingredient Facts
p-Hydroxyanisole
AKA: 4-Methoxyphenol, Mequinol, 150-76-5, 4-Hydroxyanisole, P-Methoxyphenol, Phenol, 4-methoxy-, HYDROQUINONE MONOMETHYL ETHER, MEHQ, Leucobasal
Antioxidant · Antioxidant · EWG: 8
Synthetic
Antioxidant
Not Clean
Mequinol is a phenol used in various applications. It is used as an inhibitor for acrylic monomers and acrylonitirles, as a stabilizer for chlorinated hydrocarbons and ethyl cellulose, as an ultraviolet inhibitor, as a chemical intermediate in the manufacture of antioxidants, pharmaceuticals, plasticizers, and dyestuffs. It is found as an active ingredient in topical drugs used for skin depigmentation indicated for the treatment of solar lentigines.
Solubility Soluble (NTP, 1992)
Formula
C7H8O2
Mol. Weight
124.14
CAS #
150-76-5
Form
Powder
State
Hydroquinone monomethyl ether appears as pink crystals or white waxy solid. (NTP, 1992)
See origin →
Functions
Antioxidant
Fights free radicals — the unstable molecules from UV, pollution, and stress that break down collagen and cause premature aging.
Reducing
Neutralizes Free Radicals
Traditional Use
A synthetic aromatic compound developed in the 20th century as a preservative and fragrance component. Used in cosmetics as an antioxidant and skin-conditioning agent in modern formulations.
Skin Types
●all-skin-types
Best For
General
Pregnancy & Breastfeeding Safe
No
EWG
8
CIR
Safe as used
Pregnancy
No
CIR Safety Findings
medical-approval
all-shades-safe
Concentration Guide
0.02%
0%0%
Reg. Limit
EU regulatory limit: 0.02%. For professional use only Avoid skin contact Read directions for use carefully Source: EU Cosmetics Regulation (EC) 1223/2009, Annex III (Restricted Substances), Entry 95.
Regulatory Status
USA✔ permitted
EU✔ permitted
JAPAN✔ permitted
CANADA✔ permitted
🧂Conflict of interest.
2-Amino-4-nitrophenol.
IARC monographs on the evaluation of carcinogenic risks to humans, 1993
→
2-Amino-5-nitrophenol.
IARC monographs on the evaluation of carcinogenic risks to humans, 1993
→
4-amino-2-nitrophenol.
IARC monographs on the evaluation of the carcinogenic risk of chemicals to man, 1978
→
Polyphenols: skin photoprotection and inhibition of photocarcinogenesis.
Afaq F, Katiyar SK
Mini reviews in medicinal chemistry, 2011
→
Polyphenols: skin photoprotection and inhibition of photocarcinogenesis.
Afaq F, Katiyar SK
Mini reviews in medicinal chemistry, 2011
→
Potential skin anti-aging effects of main phenolic compounds, tremulacin and tremuloidin from Salix chaenomeloides leaves on TNF-α-stimulated human de
Ahn SY, Kim KA, Lee S, Kim KH
Chemico-biological interactions, 2024
→
Efficacy of a topical polyphenol-based formulation in palmoplantar psoriasis: an observational study.
Amato S, Dattola A, Bennardo L, Tolone M, Nisticò SP
Dermatology reports, 2025
→
Efficacy of a topical polyphenol-based formulation in palmoplantar psoriasis: an observational study.
Amato S, Dattola A, Bennardo L, Tolone M, Nisticò SP
Dermatology reports, 2025
→
Final report on the safety assessment of amino nitrophenols as used in hair dyes.
Burnett CL, Bergfeld WF, Belsito DV, Klaassen CD, Marks JG Jr et al.
International journal of toxicology, 2009
→
Final report on the safety assessment of amino nitrophenols as used in hair dyes.
Burnett CL, Bergfeld WF, Belsito DV, Klaassen CD, Marks JG Jr et al.
International journal of toxicology, 2009
→
Final report on the safety assessment of amino nitrophenols as used in hair dyes.
Burnett CL, Bergfeld WF, Belsito DV, Klaassen CD, Marks JG Jr et al.
International journal of toxicology, 2009
→
Final Amended Report on the Safety Assessment of p-Methylaminophenol Sulfate and p-Methylaminophenol
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Final Report on the Safety Assessment of 2-Amino-6-Chloro-4-Nitrophenol and 2-Amino-6-Chloro-4-Nitrophenol Hydrochloride
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Final Report on the Safety Assessment of 2-Methyl-5-Hydroxyethylaminophenol
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Final Report on the Safety Assessment of 2,4-Diaminophenol and 2,4-Diaminophenol Dihydrochloride
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Final Report on the Safety Assessment of 4-Methoxy-m-Phenylenediamine, 4-Methoxy-m-Phenylenediamine Sulfate, and 4-Methoxy-m-Phenylenediamine-HCI
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Final Report on the Safety Assessment of 6-Amino-m-Cresol, 6-Amino-o-Cresol, 4-Amino-m-Cresol, 5-Amino-4-Chloro-o-Cresol, 5-Amino-6-Chloro-o-Cresol and 4-Chloro-2-Aminophenol
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Final Report on the Safety Assessment of Amino Nitrophenols Used in Hair Dyes
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Final Report on the Safety Assessment of p-Aminophenol, m-Aminophenol, and o-Aminophenol
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Final Report on the Safety Assessment of p-Hydroxyanisole
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Final Report on the Safety Assessment of p-Methylaminophenol Sulfate
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Final Report on the Safety Assessment of Zinc Phenolsulfonate
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Final Report: Amended Safety Assessment of 4-Chloro-2-Aminophenol as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Final Report: Amended Safety Assessment of p-Hydroxyanisole as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Final Report: Safety Assessment of Sodium Benzotriazolyl Butylphenol Sulfonate as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Final Report: Safety Assessment of Tetrabromophenol Blue as Used in Cosmetics
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Re-evaluation: p-Hydroxyanisole
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
Zinc Phenolsulfonate
Cosmetic Ingredient Review (CIR) Expert Panel
International Journal of Toxicology
→
2-Amino-6-Chloro-4-Nitrophenol
European Commission
EU Cosmetic Ingredient Database (CosIng)
→
2-Methyl-5-Hydroxyethylaminophenol
European Commission
EU Cosmetic Ingredient Database (CosIng)
→
3-Nitro-p-Hydroxyethylaminophenol
European Commission
EU Cosmetic Ingredient Database (CosIng)
→
4-Amino-3-Nitrophenol
European Commission
EU Cosmetic Ingredient Database (CosIng)
→
4-Hydroxypropylamino-3-Nitrophenol
European Commission
EU Cosmetic Ingredient Database (CosIng)
→
p-Hydroxyanisole
European Commission
EU Cosmetic Ingredient Database (CosIng)
→
Sodium Benzotriazolyl Butylphenol Sulfonate
European Commission
EU Cosmetic Ingredient Database (CosIng)
→
Zinc Phenolsulfonate
European Commission
EU Cosmetic Ingredient Database (CosIng)
→
2-Amino-5-Nitrophenol
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
→
2-Amino-6-Chloro-4-Nitrophenol
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
→
2-Methyl-5-Hydroxyethylaminophenol
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
→
3-Nitro-p-Hydroxyethylaminophenol
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
→
4-Amino-3-Nitrophenol
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
→
4-Hydroxypropylamino-3-Nitrophenol
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
→
p-Hydroxyanisole
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
→
Sodium Benzotriazolyl Butylphenol Sulfonate
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
→
Zinc Phenolsulfonate
Environmental Working Group (EWG)
EWG Skin Deep Cosmetics Database
→
2-Amno-6-Chloro-4-Nitrophenol.
Fiume MM
International journal of toxicology, 2017
→
Novel Bioactive Multifunctional Polyphenols: A Chemo-Enzymatic Approach.
Flourat AL, Thiébault E, Martinez A, Brunissen F, Dosso A et al.
Chemistry (Weinheim an der Bergstrasse, Germany), 2026
→
2-Amino-1,2-bis(4-methoxyphenol) ethanol and its salts
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
2-Amino-4-nitrophenol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
2-Amino-5-nitrophenol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
4-Amino-2-nitrophenol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
4-Benzyloxyphenol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
4-Ethoxyphenol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
4-Methoxy-m-phenylenediamine and its sulfate salts
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
4-Methoxy-m-phenylenediamine-HCl
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
4-tert-Butylphenol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
4,4'-Isopropylidenediphenol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
Dinitrophenol isomers
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
p-Hydroxyanisole
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
Phenol
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
Phenolphthalein
Health Canada
Health Canada Cosmetic Ingredient Hotlist
→
Occupational allergic contact dermatitis caused by epoxy diacrylate in ultraviolet-light-cured paint, and bisphenol A in dental composite resin.
Jolanki R, Kanerva L, Estlander T
Contact dermatitis, 1995
→
Effects of antioxidant polyphenols on TNF-alpha-related diseases.
Kawaguchi K, Matsumoto T, Kumazawa Y
Current topics in medicinal chemistry, 2011
→
Effects of antioxidant polyphenols on TNF-alpha-related diseases.
Kawaguchi K, Matsumoto T, Kumazawa Y
Current topics in medicinal chemistry, 2011
→
Effects of antioxidant polyphenols on TNF-alpha-related diseases.
Kawaguchi K, Matsumoto T, Kumazawa Y
Current topics in medicinal chemistry, 2011
→
Antioxidant effects of phenolic compounds in through the distillation of Lonicera japonica & Chenpi extract and anti-inflammation on skin keratinocyte
Kim HH, Jeong SH, Park MY, Bhosale PB, Abusaliya A et al.
Scientific reports, 2023
→
Antioxidant effects of phenolic compounds in through the distillation of Lonicera japonica & Chenpi extract and anti-inflammation on skin keratinocyte
Kim HH, Jeong SH, Park MY, Bhosale PB, Abusaliya A et al.
Scientific reports, 2023
→
Antioxidant effects of phenolic compounds in through the distillation of Lonicera japonica & Chenpi extract and anti-inflammation on skin keratinocyte
Kim HH, Jeong SH, Park MY, Bhosale PB, Abusaliya A et al.
Scientific reports, 2023
→
Antioxidant effects of phenolic compounds in through the distillation of Lonicera japonica & Chenpi extract and anti-inflammation on skin keratinocyte
Kim HH, Jeong SH, Park MY, Bhosale PB, Abusaliya A et al.
Scientific reports, 2023
→
Analytical Method Development and Dermal Absorption of 4-Amino-3-Nitrophenol (4A3NP), a Hair Dye Ingredient under the Oxidative or Non-Oxidative Condi
Kim HY, Kim YJ, Lee JD, Kim HR, Seo DW
Toxics, 2024
→
Molecular modeling and phenoloxidase inhibitory activity of arbutin and arbutin undecylenic acid ester.
Masyita A, Salim E, Asri RM, Nainu F, Hori A et al.
Biochemical and biophysical research communications, 2021
→
Sargassum horneri extract containing polyphenol alleviates DNCB-induced atopic dermatitis in NC/Nga mice through restoring skin barrier function.
Mihindukulasooriya SP, Dinh DTT, Herath KHINM, Kim HJ, Han EJ et al.
Histology and histopathology, 2022
→
Microwave-Assisted Extraction of Phenolic Compounds and Antioxidants for Cosmetic Applications Using Polyol-Based Technology.
Myat Win S, Saelee M, Myo H, Khat-Udomkiri N
Journal of visualized experiments : JoVE, 2024
→
Microwave-Assisted Extraction of Phenolic Compounds and Antioxidants for Cosmetic Applications Using Polyol-Based Technology.
Myat Win S, Saelee M, Myo H, Khat-Udomkiri N
Journal of visualized experiments : JoVE, 2024
→
Allergic contact dermatitis due to nonylphenol ethoxylate (nonoxynol-6).
Nethercott JR, Lawrence MJ
Contact dermatitis, 1984
→
Lingonberry (Vaccinium vitis-idaea L.) Fruit Phenolic Bio...
Pirjo Pärnänen, Sari Niikko, Hanna Lähteenmäki, Ismo T Räisänen, Taina Tervahartiala, Timo Sorsa + 1 more
Microorganisms, 2024
→
Phenolic Composition and Biological Properties of Wild and Commercial Dog Rose Fruits and Leaves.
Polumackanycz M, Kaszuba M, Konopacka A, Marzec-Wróblewska U, Wesolowski M et al.
Molecules (Basel, Switzerland), 2020
→
Antioxidant capacity, phenolic content, and profiling of phenolic compounds in the seeds, skin, and pulp of Vitis rotundifolia (Muscadine Grapes) As d
Sandhu AK, Gu L
Journal of agricultural and food chemistry, 2010
→
Phenolic-enriched maple syrup extract protects human keratinocytes against hydrogen peroxide and methylglyoxal induced cytotoxicity.
Sheng J, Liu C, Petrovas S, Wan Y, Chen HD et al.
Dermatologic therapy, 2020
→
Allergy to 3-nitro-p-hydroxyethylaminophenol and 4-amino-3-nitrophenol in a hair dye.
Søsted H, Menné T
Contact dermatitis, 2005
→
Protective Role of Phenolic Compounds from Whole Cardamom (Elettaria cardamomum (L.) Maton) against LPS-Induced Inflammation in Colon and Macrophage C
Sreedharan S, Nair V, Cisneros-Zevallos L
Nutrients, 2023
→
Antioxidant screening and phenolic content of ethanol extracts of selected Baja California Peninsula macroalgae.
Tenorio-Rodriguez PA, Murillo-Álvarez JI, Campa-Cordova ÁI, Angulo C
Journal of food science and technology, 2017
→
Zinc Phenolsulfonate.
Tucker R, Bergfeld WF, Belsito DV, Cohen DE, Klaassen CD et al.
International journal of toxicology, 2024
→
Severe contact urticarial syndrome due to oxidative hair dye containing para-aminophenol and sodium-methyl-oleoyl-taurate.
Uehara S, Inomata N, Suzuki A, Matsuura M, Aihara M
The Journal of dermatology, 2014
→
Extraction of Polyphenols and Vitamins Using Biodegradable ATPS Based on Ethyl Lactate.
Velho P, Marques L, Macedo EA
Molecules (Basel, Switzerland), 2022
→
Profiling and quantification of phenolic compounds in Camellia seed oils: Natural tea polyphenols in vegetable oil.
Wang X, Zeng Q, Del Mar Contreras M, Wang L
Food research international (Ottawa, Ont.), 2017
→
Profiling and quantification of phenolic compounds in Camellia seed oils: Natural tea polyphenols in vegetable oil.
Wang X, Zeng Q, Del Mar Contreras M, Wang L
Food research international (Ottawa, Ont.), 2017
→
Formulation of Propolis Phenolic Acids Containing Microemulsions and Their Biopharmaceutical Characterization.
Žilius M, Ramanauskienė K, Juškaitė V, Briedis V
Evidence-based complementary and alternative medicine : eCAM, 2016
→
Verified Jun 2026 · 🧪 = conflict
Data: PubChem · CosIng · EWG · CIR