Hydroquinone CAS 123-31-9
Introduction：Basic information about Hydroquinone CAS 123-31-9, including its chemical name, molecular formula, synonyms, physicochemical properties, and safety information, etc.
Hydroquinone Basic information
| Product Name: | Hydroquinone |
| Synonyms: | Hydroquinone, 99.5%, 99.5%;HYDROXYQUINOL;HYDROCHINONE;HYDROQUINONE;AKOS BBS-00004220;hydroquinone--1,4-benzenediol;Idrochinone;Melanex |
| CAS: | 123-31-9 |
| MF: | C6H6O2 |
| MW: | 110.11 |
| EINECS: | 204-617-8 |
| Product Categories: | corrosion inhibitor;Aromatics;Redox Catalysts (Environmentally-friendly Oxidation);Environmentally-friendly Oxidation;Synthetic Organic Chemistry;Intermediates of Dyes and Pigments;PINDAC;Building Blocks;Chemical Synthesis;Nutrition Research;Organic Building Blocks;Oxygen Compounds;Phytochemicals by Plant (Food/Spice/Herb);Polyols;Vaccinium myrtillus (Bilberry);123-31-9 |
| Mol File: | 123-31-9.mol |
Hydroquinone Chemical Properties
| Melting point | 172-175 °C(lit.) |
| Boiling point | 285 °C(lit.) |
| density | 1.32 |
| bulk density | 600kg/m3 |
| vapor density | 3.81 (vs air) |
| vapor pressure | 1 mm Hg ( 132 °C) |
| refractive index | 1.6320 |
| Fp | 165 °C |
| storage temp. | Store below +30°C. |
| solubility | H2O: 50 mg/mL, clear |
| pka | 10.35(at 20℃) |
| form | Needle-Like Crystals or Crystalline Powder |
| color | White to off-white |
| Odor | odorless |
| biological source | synthetic |
| Water Solubility | 70 g/L (20 ºC) |
| Sensitive | Air & Light Sensitive |
| Merck | 14,4808 |
| BRN | 605970 |
| Henry's Law Constant | (x 10-9 atm?m3/mol):<2.07 at 20 °C (approximate - calculated from water solubility and vapor pressure) |
| Exposure limits | NIOSH REL: 15-min ceiling 2, IDLH 50; OSHA PEL: TWA 2;ACGIH TLV: TWA 2 (adopted). |
| Stability: | Stable. Combustible. Incompatible with strong oxidizing agents, strong bases, oxygen, ferric salts. Light and air-sensitive. Discolours in air. |
| Cosmetics Ingredients Functions | FRAGRANCE HAIR DYEING REDUCING ANTIOXIDANT BLEACHING |
| Cosmetic Ingredient Review (CIR) | Hydroquinone (123-31-9) |
| InChI | 1S/C6H6O2/c7-5-1-2-6(8)4-3-5/h1-4,7-8H |
| InChIKey | QIGBRXMKCJKVMJ-UHFFFAOYSA-N |
| SMILES | Oc1ccc(O)cc1 |
| LogP | 0.59 at 20℃ |
| CAS DataBase Reference | 123-31-9(CAS DataBase Reference) |
| NIST Chemistry Reference | Hydroquinone(123-31-9) |
| IARC | 3 (Vol. 15, Sup 7, 71) 1999 |
| EPA Substance Registry System | Hydroquinone (123-31-9) |
Safety Information
| Hazard Codes | Xn,N |
| Risk Statements | 22-40-41-43-50-68-R68-R50-R43-R41-R40-R22 |
| Safety Statements | 26-36/37/39-61-S61-S36/37/39-S26 |
| RIDADR | 2662 |
| OEL | Ceiling: 2 mg/m3 [15-minute] |
| WGK Germany | 3 |
| RTECS | MX3500000 |
| Autoignition Temperature | 930 °F |
| TSCA | TSCA listed |
| HazardClass | 9 |
| PackingGroup | III |
| HS Code | 29072210 |
| Storage Class | 11 - Combustible Solids |
| Hazard Classifications | Acute Tox. 4 Oral Aquatic Acute 1 Aquatic Chronic 1 Carc. 2 Eye Dam. 1 Muta. 2 Skin Sens. 1B |
| Hazardous Substances Data | 123-31-9(Hazardous Substances Data) |
| Toxicity | LD50 orally in rats: 320 mg/kg (Woodard) |
| IDLA | 50 mg/m3 |
| Description | Hydroquinone (HQ) is produced by the oxidation of aniline orphenol, by the reduction of quinone, or from a reaction ofacetylene and carbon monoxide. Hydroquinone occurs naturallyas a glucose ether, also known as arbutin, in the leaves ofmany plants and in fruits, as well as one of the agents used in thedefense mechanism of the bombardier beetle, family Carabidae. |
| Chemical Properties | white needle-like crystals or crystalline powder |
| Chemical Properties | Hydroquinone, a colorless, hexagonal prism, has been reported to be a good antimitoticand tumor-inhibiting agent. It is a reducing agent used in a photographic developer,which polymerizes in the presence of oxidizing agents. In the manufacturing industryit may occur include bacteriostatic agent, drug, fur processing, motor fuel, paint, organicchemicals, plastics, stone coating, and styrene monomers. |
| Physical properties | Colorless to pale brown, odorless, hexagonal crystals |
| Originator | Quinnone,Dermohr,US,1980 |
| Uses | reducing agent prevents polymerization of resin monomers lightens darkened skin, light sensitive |
| Uses | Use as photographic reducer and developer; as reagent in the determination of small quantities of phosphate; as antioxidant. Depigmentor |
| Uses | hydroquinone is a pigment-lightening agent used in bleaching creams. Hydroquinone combines with oxygen very rapidly and becomes brown when exposed to air. Although it occurs naturally, the synthetic version is the one commonly used in cosmetics. Application to the skin may cause allergic reaction and increase skin sun sensitivity. Hydroquinone is potentially carcinogenic and is associated with causing ochronosis, a discoloration of the skin. The u.S. FDA has banned hydroquinone from oTC cosmetic formulations, but allows 4 percent in prescription products. Its use in cosmetics is prohibited in some european countries and in Australia. |
| Uses | K channel agonist, antihypertensive |
| Uses | Photographic reducer and developer; antioxidant; stabilizing agent for some polymers; intermediate in the manufacturing of some dyes and pigments; in cosmetic formulations. |
| Definition | ChEBI: A benzenediol comprising benzene core carrying two hydroxy substituents para to each other. |
| Indications | Hydroquinone interferes with the production of thepigment melanin by epidermal melanocytes through atleast two mechanisms: it competitively inhibits tyrosinase,one of the principal enzymes responsible for convertingtyrosine to melanin, and it selectively damagesmelanocytes and melanosomes (the organelles withinwhich melanin is stored). |
| Production Methods | There are three current manufacturing processes for HQ:oxidative cleavage of diisopropylbenzene, oxidation of aniline,and hydroxylation of phenol. Diisopropylbenzene is air oxidized to the intermediatediisopropylbenzene bishydroperoxide. This hydroperoxideis purified by extraction and reacted further to formhydroquinone. The purified product is isolated by filtrationand packaged. The process can be almost entirely closed,continuous, computer-controlled, and monitored. HQcan also be prepared by oxidizing aniline to quinone inthe presence of manganese dioxide and sulfuric acid.p-Benzoquinone is then reduced to HQ using iron oxide.The resulting hydroquinone is crystallized and dried.The process occurs in a closed system. HQis also manufactured by hydroxylation of phenol usinghydrogen peroxide as a hydroxylation agent. The reaction iscatalyzed by strong mineral acids or ferrous or cobalt salts. |
| Manufacturing Process | Into a pressure reactor there was charged 100 ml of methanol and 1 g ofdiruthenium nonacarbonyl. The reactor was closed, cooled in solid carbondioxide/acetone, and evacuated. Acetylene, to the extent of 1 mol (26 g), wasmetered into the cold reactor. Carbon monoxide was then pressured into thisvessel at 835-980 atmospheres, during a period of 16.5 hours; while thereactor was maintained at 100°C to 150°C. The reactor was then cooled toroom temperature and opened. The reaction mixture was removed from the vessel and distilled at a pressure of 30-60 mm, and a bath temperature of 30°C to 50°C until the methanol hadall been removed. The extremely viscous tarry residue remaining in the stillpot was given a very crude distillation, the distillate boiling at 82°C to132°C/2 mm. In an attempt to purify this distillate by a more carefuldistillation, 5.3 g of a liquid distilling from 53°C to 150°C/5 mm was collected.At this point, much solid sublimate was noted not only in this distillate but inthe condenser of the still. 7 g of the solid sublimate was scraped out of thecondenser of the still. Recrystallization of the sublimate from ethyl acetatecontaining a small amount of petroleum ether gave beautiful crystals meltingat 175°C to 177°C (5 g). Infrared analysis confirmed that this compound washydroquinone (9% conversion). |
| Brand name | Aida;Ambi- skin tone;Black and white;Creme des 3 fleur d'orient;Eldopaque forte;Eldoquin forte 4% cream;Epocler;Esoterica facial;Esoterica regular;Esoterica sensitive skin;Esoterica sunscreen;Melanex topical sollution;Melpaque hp;Melqui hp;Neostrata aha gel;Neostrata hq;Nuquin hp;Pigmanorm;Porcelana;Sinquin;Solaquin forte sun bleaching;Superfade age spot;Ultraquin plaine. |
| Therapeutic Function | Depigmentor |
| World Health Organization (WHO) | Hydroquinone was introduced in 1965 as a topical depigmentingagent for hyperpigmentation. At high concentrations hydroquinone is corrosiveand in most countries has been restricted to the level of approximately 2% andlimited to the period of less than 2 months. Additional consideration for restrictiveaction is that animal experiments have also demonstrated carcinogenic andmutagenic potential of hydroquinone. |
| Synthesis Reference(s) | Chemistry Letters, 14, p. 731, 1985 The Journal of Organic Chemistry, 50, p. 1722, 1985 Tetrahedron Letters, 22, p. 2337, 1981 DOI: 10.1016/S0040-4039(01)82900-2 |
| General Description | Light colored crystals or solutions. May irritate the skin, eyes and mucous membranes. Mildly toxic by ingestion or skin absorption. |
| Air & Water Reactions | Darkens on exposure to air and light. Miscible in water. Solutions become brown in air due to oxidation. Oxidation is very rapid in the presence of alkali. |
| Reactivity Profile | Hydroquinone is a slight explosion hazard when exposed to heat. Incompatible with strong oxidizing agents. Also incompatible with bases. Hydroquinone reacts with oxygen and sodium hydroxide. Reacts with ferric salts . Hot and/or concentrated NaOH can cause Hydroquinone to decompose exothermically at elevated temperature. (NFPA Pub. 491M, 1975, 385) |
| Hazard | Toxic by ingestion and inhalation, irritant.Questionable carcinogen. |
| Health Hazard | Exposures to hydroquinone in large quantities by accidental oral ingestion produce toxicityand poisoning. The symptoms of poisoning include, but are not limited to, blurred speech,tinnitus, tremors, sense of suffocation, vomiting, muscular twitching, headache, convul-sions, dyspnea and cyanosis from methemoglobinemia, coma, and collapse from respira-tory failure. Occupational workers should be allowed to work with protective clothing anddust masks with full-face or goggles to protect the eyes, and under proper management. |
| Health Hazard | Hydroquinone is very toxic; the probable oral lethal dose for humans is 50-500 mg/kg, or between 1 teaspoon and 1 ounce for a 150 lb. person. It is irritating but not corrosive. Fatal human doses have ranged from 5-12 grams, but 300-500 mg have been ingested daily for 3-5 months without ill effects. Death is apparently initiated by respiratory failure or anoxia. |
| Fire Hazard | Dust cloud may explode if ignited in an enclosed area. Hydroquinone can react with oxidizing materials and is rapidly oxidized in the presence of alkaline materials. Oxidizes in air. |
| Flammability and Explosibility | Non flammable |
| reaction suitability | reagent type: reductant |
| Contact allergens | Hydroquinone is used in photography developers (blackand white, X-ray, and microfilms), in plastics, in hairdyes as an antioxidant and hair colorant. Hydroquinoneis found in many skin bleaching creams. |
| Clinical Use | Hydroquinone is applied topically to treat disorderscharacterized by excessive melanin in the epidermis,such as melasma. In the United States, nonprescriptionskin-lightening products contain hydroquinone at concentrationsof 2% or less; higher concentrations areavailable by prescription. |
| Side effects | The incidence of adverse effects with hydroquinoneincreases in proportion to its concentration. A relativelycommon side effect is local irritation, which may actuallyexacerbate the discoloration of the skin beingtreated. Allergic contact dermatitis occurs less commonly.A rare but more serious complication is exogenousochronosis, in which a yellow-brown pigment depositedin the dermis results in blue-black pigmentationof the skin that may be permanent. |
| Potential Exposure | Tumorigen,Mutagen; Reproductive Effector; Human Data; PrimaryImritant. Hydroquinone is a reducing agent and is used as anindustrial chemical, chemical intermediate, pharmaceutical,and veterinary drug; as a photographic developer; and as anantioxidant or stabilizer for certain materials, which polymer-ize in the presence of oxidizing agents. Many of its derivativesare used as bacteriostatic agents, and others, particularly 2,5- bis(ethyleneimino) hydroquinone, have been reported to begood antibiotic and tumor-inhibiting agents. |
| First aid | If this chemical gets into the eyes, remove anycontact lenses at once and irrigate immediately for at least15 min, occasionally lifting upper and lower lids. Seek med-ical attention immediately. If this chemical contacts theskin, remove contaminated clothing and wash immediatelywith soap and water. Seek medical attention immediately. Ifthis chemical has been inhaled, remove from ex posure,begin rescue breathing (using universal precautions, includ-ing resuscitation mask) if breathing has stopped and CPR ifheart action has stopped. Transfer promptly to a medicalfacility. When this chemical has been swallowed, get medi-cal attention. Give large quantities of water and inducevomiting. Do not make an unconscious person vomit. |
| Carcinogenicity | No case reports of cancer associatedwith HQ exposure have been published. |
| Source | Hydroquinone occurs naturally in strawberry tree leaves, pears, blackberries, Chinesealpenrose, bilberries, blackberries, hyacinth flowers, anise, cowberries, and lingonberries (Duke,1992). |
| Environmental fate | Biological. In activated sludge, 7.5% mineralized to carbon dioxide after 5 d (Freitag et al.,1985). Under methanogenic conditions, inocula from a municipal sewage treatment plant digesterdegraded hydroquinone to phenol prior to being mineralized to carbon dioxide and methane(Young and Rivera, 1985). In various pure cultures, hydroquinone degraded to the followingintermediates: benzoquinone, 2-hydroxy-1,4-benzoquinone, and β-ketoadipic acid. Hydroquinonealso degraded in activated sludge but no products were identified (Harbison and Belly, 1982).Heukelekian and Rand (1955) reported a 5-d BOD value of 0.74 g/g which is 39.2% of theThOD value of 1.89 g/g. In activated sludge inoculum, following a 20-d adaptation period, 90.0%COD removal was achieved. The average rate of biodegradation was 54.2 mg COD/g?h (Pitter,1976). Photolytic. A carbon dioxide yield of 53.7% was achieved when hydroquinone adsorbed onsilica gel was irradiated with light (λ >290 nm) for 17 h (Freitag et al., 1985).Chemical/Physical. Ozonolysis products reported are p-quinone and dibasic acids (Verschueren,1983). Moussavi (1979) studied the autoxidation of hydroquinone in slightly alkaline (pH 7 to 9)aqueous solutions at room temperature. The oxidation of hydroquinone by oxygen followedfirst-order kinetics that yielded hydrogen peroxide and p-quinone as products. At pH values of 7.0,8.0, and 9.0, the calculated half-lives of this reaction were 111, 41, and 0.84 h, respectively(Moussavi, 1979). Chlorine dioxide reacted with hydroquinone in an aqueous solution forming p-benzoquinone (Wajon et al., 1982). Kanno et al. (1982) studied the aqueous reaction of hydroquinone and other substituted aromatic hydrocarbons (aniline, toluidine, 1- and 2-naphthylamine, phenol, cresol,pyrocatechol, resorcinol, and 1-naphthol) with hypochlorous acid in the presence of ammoniumion. They reported that the aromatic ring was not chlorinated as expected but was cleaved bychloramine forming cyanogen chloride. As the pH was lowered, the amount of cyanogen chlorideformed increased (Kanno et al., 1982). At influent concentrations of 1.0, 0.1, 0.01, and 0.001 mg/L, the GAC adsorption capacitieswere 160, 90, 51, and 29 mg/g, respectively (Dobbs and Cohen, 1980). |
| storage | (1) Color Code-- Yellow Stripe (strong reducingagent): Reactivity Hazard; Store separately inan area iso-lated from flammables, combustibles, or other yellow-codedmaterials. (2) Color Code- _Blue: Health Hazard/Poison:Store in a secure poison location. Prior to working with thischemical you should be trained on its proper handling andstorage. Hydroquinone must be stored to avoid contact withsodium hydroxide since violent reactions occur. Store intightly closed containers in a cool, well-ventilated areaaway from oxidizing materials. Where possible, automati-cally pump liquid from drums or other storage containers toprocess containers. |
| Shipping | This compound requires aa shipping label of“POISONOUS/TOXIC MATERIALS.”It falls in HazardClass 6.1 and Packing Group II. |
| Purification Methods | Crystallise quinol from acetone, *benzene, EtOH, EtOH/*benzene, water or acetonitrile (25g in 30mL), preferably under nitrogen. Dry it under vacuum. [Wolfenden et al. J Am Chem Soc 109 463 1987, Beilstein 6 H 836, 6 IV 5712.] |
| Toxicity evaluation | Benzene, phenol, and hydroquinone are metabolized in vivo tobenzoquinone and excreted as the mercapturate, N-acetyl-S-(2,5-dihydroxyphenyl)-L-cysteine. Hydroquinone is a reducingcosubstrate for peroxidase enzymes, and the resultant semiquinoneand p-benzoquinone may bind to DNA. |
| Incompatibilities | Hydroquinone is a reducing agent. Dustforms an explosive mixture with air. May explode on con-tact with oxygen. Incompatible with strong oxidizers, caus-tics; reacts violently with sodium hydroxide. May beoxidized to quinone at room temperatures in the presence ofmoi sture. |
| Toxics Screening Level | The initial threshold screening level (ITSL) for hydroquinone (CAS # 123-31-9) is140 μg/m 3 based on an annual averaging time. The initial risk screening level (IRSL) is0.058 μg/m 3 with an annual averaging time, and the secondary risk screening level(SRSL) is 0.58 μg/m 3 with an annual averaging time. |
Hydroquinone Preparation Products And Raw materials
| Raw materials | Sulfuric acid-->Iron-->Aniline-->ZINC-->Manganese dioxide-->Activated carbon-->Sodium metabisulfite-->Catechol-->Oxalic acid-->1,4-Benzoquinone-->Manganese-->Bisphenol A-->Aniline sulfate-->Methanol-->Acetylene |
| Preparation Products | 1,4-Dimethoxybenzene-->Quizalofop-p-ethyl-->2-CHLOROPYRIMIDINE-4-CARBONITRILE-->Chloral hydrate-->methyl(±)cis，trans-2，2-dimethyl-3-(2-methyl-1-propenyl cyclopropane carboxylate)-->X-PHOS-->Ethyl chrysanthemumate-->4-Acetoxystyrene-->7-HYDROXYISOFLAVONE-->Butylated hydroxyanisole-->2,5-Dimethoxyaniline-->Fluazifop-P-butyl-->2-[N-(2-Cyanoethyl)-4-[(2,6-dichloro-4-nitrophenyl)azo]anilino]ethyl acetate-->Allyl hexanoate-->4-CHLORO-8-(TRIFLUOROMETHYL)QUINOLINE-->(1,1-DIMETHYL-PROP-2-YNYL)-HYDRAZINE-->1-(2,5-Dimethoxyphenyl)-2-oximino-1-propanone-->1,2,4-Trimethoxybenzene-->1,2-NAPHTHALIC ANHYDRIDE-->N-NONYL ACRYLATE-->2,5-Di-tert-butylhydroquinone-->2-Hydroxyethyl methacrylate-->ethyl 3,3-dimethylpent-4-en-1-oate-->Pirenoxine-->Hydroxypropyl acrylate-->Chloro(1,5-cyclooctadiene)iridium(I) dimer-->4-Phenoxyphenol-->tert-Butylhydroquinone-->Fast Blue BB-->2,5-Dimethoxy-4-chloroaniline-->3-SULFOLENE-->Fluazifop-butyl-->2-AMINO-1-(2,5-DIMETHOXYPHENYL)-1-PROPANONE-->3-METHYL-2,5-DIHYDROTHIOPHENE-1,1-DIOXIDE-->2,3-DIMETHYL-1,3-BUTADIENE-->enbucrilate-->ammonium manganous sulfate-->1,4-Diacetoxybenzene-->2,5-Dihydroxybenzoic acid-->4-[(6-Chloro-1,3-benzoxazol-2-yl)oxy]phenol |
