Hydroquinone

EU 1223/2009 Annex III — SCCS opinion: Opinion on The Use of Benzoyl Peroxide (BPO)

EU 1223/2009 Annex III — SCCS opinion: Hydroquinone (HQ)

EU 1223/2009 Annex III — SCCS opinion: Hydroquinone methylether (MEHQ) in artificial nail systems

EU 1223/2009 Annex III — SCCS opinion: Opinion concerning Hydroquinone (1

EU 1223/2009 Annex III — SCCS opinion: 4-Dihydroxybenzene) as a Hair Dye Constituent

Analytical Methods The purity of Hydroquinone, derivatized and underivatized samples, has been determined using gas chromatography with a flame ionization detector (GUFID) JAm Co11 Toxicol, Vol. 13, No. 3, 1994 II  Distributed for Comment Only -- Do Not Cite or Quote H YDROQUINONE 169 (Eastman Kodak Company, 1988, 1989). The structure of Hydroquinone was confirmed by gas chromatography-mass spectrometry (GUMS), using electron impact ionization (EI). Rate of Hydroquinone Disappearance During Its Use in Hair Dyes Hydroquinone, which acts as a regulating agent allowing some control of the color-forming coupling reactions, is a “consumable” in the hair dyeing procedure, with its actual concentration decreasing as the color-forming reactions proceed (L’Oreal, 1990). To determine how much of the Hydroquinone is consumed, three commercial hair dye formulations were used to measure the rate of disappearance of Hydro- quinone during the hair dyeing procedure (L’Oreal, 1990). Two of the formula- tions contained 0.08% (w/w) and the third contained 0.15% (w/w) Hydroquinone. An oxidation cream containing 6% (w/w) hydrogen peroxide was used for oxida- tion of the mixtures. The test article was prepared by mixing 15 g of the cream oxidant with 15 g of the hair dye. It was then uniformly applied with a paintbrush to a 30 cm long (15 g) lock of natural hair. After 5, 10, 20, and 30 min, 2.5 g samples of the hair dye mixture were collected from the hair lock and assayed in a high-performance liquid chromatography (HPLC) system. (Results of the system calibration showed that it responded linearly with respect to concentration of Hydroquinone for the range 0.8-80 Fg/ml.) For each of the three formulations, the percentage of residual Hydroquinone was determined as a function of time. The amount of Hydroquinone that remained … [kırpıldı — bölüm toplam 214341 karakter]

Repeated Dose Toxicity Dermal – Non-Human Hydroquinone (2% in a topical cream) caused liver and kidney damage when administered to rabbits (n = 6) for 6 weeks.21 The test substance was administered daily to one or both ears of the rabbits or to the shaved abdomen; the rabbits were killed and necropsied. Findings in the liver included hydropic degeneration, bile duct hyperplasia, and glycogen depletion. Hydropic degeneration, hyaline casts, congestion, perivascular edema, and fibrosis were observed in the kidneys. For both the kidneys and livers, the effects were greater in the groups in which the test substance was administered to the ears. Dermal effects included hyperkeratosis, lymphocytic and eosinophilic infiltration, and congestion of dermal blood vessels. Dermal depigmentation was observed when hydroquinone (5% in propylene glycol/ethanol, 50:50) or p- hydroxyanisole (5% in propylene glycol/ethanol, 50:50) was dermally administered to multiple sites of the backs of Yucatan miniature pigs (n = 2) twice/day, 7 days/week for 90 days.22 Microscopic examination of biopsies from the test area showed decreased pigment and melanocytes. GENOTOXICITY In Vitro HYDROQUINONE Hydroquinone (0, 10, 20, 30, 40 µM) did not induce DNA damage to human L-02 liver cells but was genotoxic to the same cell line with silenced DNA polymerase eta (η) after 24 h of incubation.23 DNA damage was determined by means of the Comet assay, apoptosis and cell cycle distribution were determined using flow cytometry, the mRNA expression levels of Polη were determined by real-time PCR, the protein expression levels of Polη and γ-H2AX were determined by Western blot, and γ-H2AX foci were visualized by confocal laser scanning fluorescence microscopy after cells were exposed to … [kırpıldı — bölüm toplam 13041 karakter]

Definition and Structure Hydroquinone (CAS No, 123-31-9) is defined in the International Cosmetic Ingredient Dictionary and Handbook as the aromatic organic compound that conforms to the formula in Figure 1.9 It is currently reported to function in cosmetics as an antioxidant, fragrance ingredient, hair colorant, reducing agent, and skin bleaching agent. Hydroquinone is a common name for 1,4-dihydroxybenzene. Hydroquinone is a substituted phenol (Figure 1). This aromatic diol is a white to off-white crystalline material. As noted in the year 2010 report on this ingredient, hydroquinone is most commonly produced through hydroperoxidation of p-diisopropylbenzene, hydroxylation of phenol, or oxidation of aniline.3 OH HO Hydroquinone Figure 1. Hydroquinone. USE Cosmetic Hydroquinone, alone or in combination with p-hydroxyanisole, is used as a stabilizer that inhibits the polymerization in the liquid component of 2-component methacrylate artificial nail systems.10 The maximum concentration of hydroquinone alone, or in combination with p-hydroxyanisole, is reported to be 200 ppm (0.02%). After mixing 2 parts liquid to 1 part powder in preparation for use, the final concentration of hydroquinone, or hydroquinone and p-hydroxyanisole combined is approximately 133 ppm (0.0133%). When used as a nail adhesive, a brush is wetted in the liquid component which contains the stabilizer(s) and acrylate monomers. The wetted brush is then dipped into the powder which contains the initiator to produce an 'aspirin sized' bead. … [kırpıldı — bölüm toplam 7079 karakter]

Repeated Dose Toxicity Dermal – Non-Human Hydroquinone (2% in a topical cream) caused liver and kidney damage when administered to rabbits (n=6) for 6 weeks.22 The test substance was administered daily to 1 or both ears (volume not specified) of the rabbits or to the shaved abdomen (2 g/cm2); the rabbits were killed and necropsied. Findings in the liver included hydropic degeneration, bile duct hyperplasia, and glycogen depletion. Hydropic degeneration, hyaline casts, congestion, perivascular edema, and fibrosis were observed in the kidneys. For both the kidneys and livers, the effects were greater in the groups in which the test substance was administered to the ears. Dermal effects included hyperkeratosis, lymphocytic and eosinophilic infiltration, and congestion of dermal blood vessels. Dermal depigmentation was observed when hydroquinone (5% in 25 µL propylene glycol/ethanol, 50:50) was dermally administered to multiple sites of the backs of Yucatan miniature pigs (n=2) twice/day, 7 days/week for 90 days.23 Microscopic examination of biopsies from the test area showed decreased pigment and melanocytes. Cytotoxicity Hydroquinone (0, 10, 20, 30, 40 µM) was not cytotoxic to human L-02 liver cells but was cytotoxic to the same cell line with silenced DNA polymerase eta (Polη) after 24 h of incubation.24 Cell survival was determined using the MTT assay. Hydroquinone (500, 750 µM) was cytotoxic, in a concentration-dependent manner, to F344 rat hepatocytes when incubated for 2 h.25 Hydroquinone was cytotoxic to human lymphocytes at 270 μM, but not at 180 μM, when incubated for 3, 24, or 48 h with metabolic activation and 3 h without metabolic activation.26 GENOTOXICITY In Vitro … [kırpıldı — bölüm toplam 19694 karakter]

Definition and Structure Hydroquinone (CAS No, 123-31-9) is defined in the International Cosmetic Ingredient Dictionary and Handbook as the aromatic organic compound that conforms to the formula in Figure 1.9 It is currently reported to function as an antioxidant, fragrance ingredient, hair colorant, reducing agent, and skin bleaching agent. Hydroquinone is a common name for 1,4-dihydroxybenzene. Hydroquinone is a substituted phenol (Figure 1). This aromatic diol is a white to off-white crystalline material. As noted in the year 2010 report on this ingredient, hydroquinone is most commonly produced through hydroperoxidation of p-diisopropylbenzene, hydroxylation of phenol, or oxidation of aniline.3 OH HO Hydroquinone Figure 1. Hydroquinone. USE Cosmetic Use in Nail Products Hydroquinone, alone or in combination with p-hydroxyanisole, is used as a stabilizer that inhibits the polymerization in the liquid component of two-component methacrylate artificial nail systems.10 The maximum concentration of hydroquinone alone, or in combination with p-hydroxyanisole, is reported to be 200 ppm (0.02%). After mixing 2 parts liquid to 1 part powder in preparation for use, the final concentration of hydroquinone, or hydroquinone and p-hydroxyanisole combined is approximately 133 ppm (0.0133%). When used as a nail adhesive, a brush is wetted in the liquid component which contains the stabilizer(s) and acrylate monomers. The wetted brush is then dipped into the powder which contains the initiator to produce an 'aspirin sized' bead. … [kırpıldı — bölüm toplam 6947 karakter]

IARC Group 3 - Not classifiable as to carcinogenicity. The available evidence is insufficient for a classification. This does NOT mean 'safe'; it means 'not enough data'. (Monograph volume: 15, Sup 7, 71). Caveat: IARC classifies HAZARD, not RISK - it says 'can cause cancer under some conditions', not 'causes cancer at cosmetic use levels'. Route and dose must be assessed separately. Data is a 01/2021 snapshot.

EPA ToxValDB skin/eye data — endpoint: Skin Sensitization, classification: Sh. Caveat: this is an aggregated record; dose, species and route of exposure must be considered together.

EPA ToxValDB skin/eye data — endpoint: Skin Sensitization, classification: Skin Sens. 1. Caveat: this is an aggregated record; dose, species and route of exposure must be considered together.

EPA ToxValDB skin/eye data — endpoint: Eye Irritation, classification: Eye Dam. 1. Caveat: this is an aggregated record; dose, species and route of exposure must be considered together.

EPA ToxValDB skin/eye data — endpoint: Eye Irritation, classification: Serious eye damage/eye irritation - Category 2. Caveat: this is an aggregated record; dose, species and route of exposure must be considered together.

EPA ToxValDB skin/eye data — endpoint: Skin Irritation, classification: Not classified. Caveat: this is an aggregated record; dose, species and route of exposure must be considered together.

EPA ToxCast ER model: NO estrogen receptor activity found (AUC agonist=0, antagonist=0). Tested in 18 in vitro assays. Caveat: this is an in vitro screening model with no dose or exposure context; it does NOT mean an effect occurs in humans at cosmetic use levels.