Products Description
maleic-anhydride.html">material/hydroquinone.html">Hydroquinone (HQ) is commonly synthesized via oxidation of aniline or phenol, reduction of quinone, or reaction between acetylene and carbon monoxide. It exists naturally as arbutin, a glucoside present in many plant leaves and fruits. It also acts as a defensive chemical in bombardier beetles of the Carabidae family.
Chemical Properties
| Item | Specification |
| Melting point | 172-175 °C(lit.) |
| Boiling point | 285 °C(lit.) |
| bulk density | 600kg/m3 |
| density | 1.32 |
| 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 | (×10-9 atm·m3/mol): <2.07 at 20 °C (estimated 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 |
| InChIKey | QIGBRXMKCJKVMJ-UHFFFAOYSA-N |
| LogP | 0.59 at 20℃ |
| CAS DataBase Reference | acetic-acid-industrial-grade.html">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
| Item | Specification |
| Hazard Codes | Xn,N |
| Risk Statements | 22-40-41-43-50-68 |
| Safety Statements | 26-36/37/39-61 |
| OEL | Ceiling: 2 mg/m3 [15-minute] |
| RIDADR | 2662 |
| WGK Germany | 3 |
| RTECS | MX3500000 |
| Autoignition Temperature | 930 °F |
| TSCA | Yes |
| HazardClass | 9 |
| PackingGroup | III |
| HS Code | 29072210 |
| Hazardous Substances Data | 123-31-9(Hazardous Substances Data) |
| Toxicity | LD50 orally in rats: 320 mg/kg (Woodard) |
| IDLA | 50 mg/m3 |
Product Application
Hydroquinone is widely used as a skin-lightening ingredient in bleaching creams. It oxidizes rapidly and turns brown upon exposure to air. Although naturally occurring, the synthetic grade is predominantly used in cosmetics. Skin application may cause allergic reactions and increased photosensitivity. It is a potential carcinogen and linked to ochronosis, a skin discoloration condition. The U.S. FDA prohibits hydroquinone in over-the-counter cosmetics but permits 4% concentration in prescription products. It is banned in cosmetic products in several European countries and Australia.
Supply & Delivery
Fast delivery time
Inventory: 2-3 working days
New production: 7-10 working days
