P-HYDROXYANISOLE (mequinol)

What official classifications and rules say for each group. A classification describes the hazard of the pure substance, not the risk of a product that contains it, which depends on the dose and the exposure.

Prohibition or serious classificationThe text prohibits the substance for this use, or ranks it among the most serious hazards (known or presumed carcinogenic, mutagenic or reprotoxic, identified endocrine disruptor).Worth watchingThe text sets a condition or flags a hazard worth knowing: allergen, suspected effect, condition for children, hazard to the aquatic environment.For informationOfficial information with no condition on a finished product: warning to read, irritation of the pure substance.

• Pregnancy and breastfeeding

  No classification harmonised by the European Union covers reproduction, the unborn child or breastfeeding for this substance. This does not mean it has been judged to have no effect during pregnancy.

• Babies and children

  The Cosmetics Regulation sets no age-related condition for this ingredient.

• Skin, eyes and allergies

  Worth watchingThe text sets a condition or flags a hazard worth knowing: allergen, suspected effect, condition for children, hazard to the aquatic environment.

  Worth watching Classified under the CLPEU regulation that classifies chemicals by their hazards (EC No 1272/2008). Regulation: eye irritation, category 2 (Eye Irrit. 2); skin sensitisation, category 1 (Skin Sens. 1).

• Environment

  No harmonised classification as hazardous to the aquatic environment, and it is not on ECHAEuropean Chemicals Agency.'s Candidate List as an endocrine disruptor for the environment.

• Read on the label

  For informationOfficial information with no condition on a finished product: warning to read, irritation of the pure substance.

  For information Annex III, entry 95, requires this to be printed on the pack: “For professional use only Avoid skin contact Read directions for use carefully”.

Allowed with restrictions

Product type

Artificial nail systems

Maximum concentration

0.02% (after mixing for use)

Other conditions

Professional use

Warning to print

For professional use only Avoid skin contact Read directions for use carefully

Entry

Annex III, No 95

Substance

Hydroquinone methylether / Mequinol

Glossary names

P-HYDROXYANISOLE

CAS

150-76-5

EC

205-769-8

Identity

CosIng identifier

41529

CAS (according to CosIng)

150-76-5

EC (according to CosIng)

205-769-8

Declared functions

Antioxidant, Reducing

Wikidata

Q2862455

PubChem

9015

ECHA InfoCard

100.005.246

InChIKey

NWVVVBRKAWDGAB-UHFFFAOYSA-N

mequinol; 4-methoxyphenol; hydroquinone monomethyl ether

Neither carcinogenic, mutagenic nor toxic for reproduction under the harmonised classification

Hazard classes

Acute toxicity, category 4 (Acute Tox. 4)
Eye irritation, category 2 (Eye Irrit. 2)
Skin sensitisation, category 1 (Skin Sens. 1)

Hazard statements

H302 H319 H317

• 12 December 2025: Nail gel, NailsUp, Germany (“Serious risk”) alert
  The product contains 2-hydroxyethyl methacrylate (HEMA) and p-hydroxyanisole (mequinol) which are prohibited in nail products for consumer use. HEMA causes serious eye irritation, skin irritation and may cause allergic skin reaction. Mequinol causes serious…
• 12 December 2025: Nail gel, Zolla, Germany (“Serious risk”) alert
  The product contains p-hydroxyanisole (mequinol) which is prohibited in nail products for consumer use. Mequinol causes serious eye irritation and may cause allergic skin reaction. The product does not comply with the Cosmetic Products Regulation.
• 12 December 2025: Nail gel, NailsUp, Germany (“Serious risk”) alert
  The product contains 2-hydroxyethyl methacrylate (HEMA) and p-hydroxyanisole (mequinol) which are prohibited in nail products for consumer use. HEMA causes serious eye irritation, skin irritation and may cause allergic skin reaction. Mequinol causes serious…

United Kingdom (Great Britain)

• Allowed with restrictions (Annex III)

Same entries as in the European Union. Their maximum concentrations are compared in the “Comparison between countries” table; other conditions (product types, warnings) may differ.

Switzerland

Regulation (EC) No 1223/2009 applies in Switzerland (Article 54 of the Ordinance on Foodstuffs and Utility Articles).

United States, federal rules

None of the integrated sections of the federal code (21 CFR 700.11 to 700.27 and 250.250) targets this name. The FDA does not publish a list of allowed ingredients.

South Korea

• Prohibited: 4-메톡시페놀(히드로퀴논모노메칠에텔 또는 p-히드록시아니솔)

  별표 1 (prohibited substances), entry 297, page 15.