Merck
CN
All Photos(1)

Documents

Safety Information

1324002

USP

Hydroquinone

United States Pharmacopeia (USP) Reference Standard

Sign Into View Organizational & Contract Pricing
All Photos(1)
Synonym(s):
1,4-Benzenediol, 1,4-Dihydroxybenzene, HQ
Linear Formula:
C6H4-1,4-(OH)2
CAS Number:
123-31-9
Molecular Weight:
110.11
Beilstein:
605970
MDL number:
MFCD00002339
PubChem Substance ID:
329750111
NACRES:
NA.24

grade

pharmaceutical primary standard

vapor density

3.81 (vs air)

vapor pressure

1 mmHg ( 132 °C)

API family

hydroquinone

autoignition temp.

930 °F

manufacturer/tradename

USP

bp

285 °C (lit.)

mp

172-175 °C (lit.)

application(s)

pharmaceutical (small molecule)

format

neat

SMILES string

Oc1ccc(O)cc1

InChI

1S/C6H6O2/c7-5-1-2-6(8)4-3-5/h1-4,7-8H

InChI key

QIGBRXMKCJKVMJ-UHFFFAOYSA-N

Looking for similar products? Visit Product Comparison Guide

Related Categories

General description

This product is provided as delivered and specified by the issuing Pharmacopoeia. All information provided in support of this product, including SDS and any product information leaflets have been developed and issued under the Authority of the issuing Pharmacopoeia.For further information and support please go to the website of the issuing Pharmacopoeia.

Application

Hydroquinone USP reference standard, intended for use in specified quality tests and assays as specified in the USP compendia.
Also, for use with USP monographs such as:
  • Hydroquinone Cream
  • Hydroquinone Topical Solution

Analysis Note

These products are for test and assay use only. They are not meant for administration to humans or animals and cannot be used to diagnose, treat, or cure diseases of any kind.  ​

Other Notes

Sales restrictions may apply.

related product

Product No.
Description
Pricing

Signal Word

Danger

Hazard Classifications

Acute Tox. 4 Oral - Aquatic Acute 1 - Aquatic Chronic 1 - Carc. 2 - Eye Dam. 1 - Muta. 2 - Skin Sens. 1B

Storage Class Code

11 - Combustible Solids

WGK

WGK 3

Flash Point(F)

329.0 °F - closed cup

Flash Point(C)

165 °C - closed cup

Regulatory Information

危险化学品

Certificates of Analysis (COA)

Search for Certificates of Analysis (COA) by entering the products Lot/Batch Number. Lot and Batch Numbers can be found on a product’s label following the words ‘Lot’ or ‘Batch’.

Already Own This Product?

Documents related to the products that you have purchased in the past have been gathered in the Document Library for your convenience.

Visit the Document Library

Difficulty Finding Your Product Or Lot/Batch Number?

Product numbers are combined with Pack Sizes/Quantity when displayed on the website (example: T1503-25G). Please make sure you enter ONLY the product number in the Product Number field (example: T1503).

Example:

T1503
Product Number
-
25G
Pack Size/Quantity

Additional examples:

705578-5MG-PW

PL860-CGA/SHF-1EA

MMYOMAG-74K-13

1000309185

enter as 1.000309185)

Having trouble? Feel free to contact Technical Service for assistance.

Lot and Batch Numbers can be found on a product's label following the words 'Lot' or 'Batch'.

Aldrich Products

  • For a lot number such as TO09019TO, enter it as 09019TO (without the first two letters 'TO').

  • For a lot number with a filling-code such as 05427ES-021, enter it as 05427ES (without the filling-code '-021').

  • For a lot number with a filling-code such as STBB0728K9, enter it as STBB0728 without the filling-code 'K9'.

Not Finding What You Are Looking For?

In some cases, a COA may not be available online. If your search was unable to find the COA you can request one.

Request COA

Jacob Levitt
Journal of the American Academy of Dermatology, 57(5), 854-872 (2007-05-01)
Recently, the US Food and Drug Administration proposed a ban on over-the-counter hydroquinone mainly on the basis of high absorption, reports of exogenous ochronosis in humans, and murine hepatic adenomas, renal adenomas, and leukemia with large doses over extended time
Mekhala Chandra et al.
Acta dermato-venereologica, 92(3), 232-235 (2011-10-18)
Post-inflammatory hyperpigmentation after acne can be as troublesome as the acne itself. Hydroquinone, a tyrosinase inhibitor, in a 4% cream can be used safely twice daily for up to 6 months to treat post-inflammatory hyperpigmentation. The efficacy of this treatment
Douglas McGregor
Critical reviews in toxicology, 37(10), 887-914 (2007-11-21)
The toxicology of hydroquinone has been reviewed on a number of previous occasions. This review targets its potential for carcinogenicity and possible modes of carcinogenic action. The evaluation made by IARC (1999) of its carcinogenic risk to humans was that
Changming Chen et al.
Plant physiology, 166(1), 370-383 (2014-07-23)
A seed's ability to properly germinate largely depends on its oxidative poise. The level of reactive oxygen species (ROS) in Arabidopsis (Arabidopsis thaliana) is controlled by a large gene network, which includes the gene coding for the hydrogen peroxide-scavenging enzyme
A P DeCaprio
Critical reviews in toxicology, 29(3), 283-330 (1999-06-24)
Hydroquinone (HQ) is a high-volume commodity chemical used as a reducing agent, antioxidant, polymerization inhibitor, and chemical intermediate. It is also used in over-the-counter (OTC) drugs as an ingredient in skin lighteners and is a natural ingredient in many plant-derived
View All Related Papers

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

Contact Technical Service