Monobenzone

LUSTROUS LEAFLETS FROM WATER

WHITE CRYSTALLINE POWDER

SOLUBILITY IN BOILNG WATER ABOUT 1.0 G/100 ML; SOL IN ALC, ETHER, BENZENE

INSOL IN WATER

FREELY SOL IN ACETONE

Practically insoluble in petroleum hydrocarbons, very soluble in benzene and alkalies.

3.92e-02 g/L

FDA approved drugs -> Active ingredient

FDA approved drugs -> Active ingredient

122.5 °C

110 - 118 °C

Warning

H317: May cause an allergic skin reaction [Warning Sensitization, Skin]

P261, P264+P265, P272, P280, P302+P352, P305+P351+P338, P321, P333+P317, P337+P317, P362+P364, and P501 (click each P-code to see the statement)

Warning

H317 (100%): May cause an allergic skin reaction [Warning Sensitization, Skin]

P261, P264+P265, P272, P280, P302+P352, P305+P351+P338, P321, P333+P317, P337+P317, P362+P364, and P501 (click each P-code to see the statement)

A tumorigen and mild skin irritant; Intraperitoneal LD50 (rat) = 4500 mg/kg; [RTECS] Emergency treatment: symptomatic chemical dermal exposure; Reported skin sensitizer in the rubber industry; [HSDB] An eye irritant; May cause skin sensitization; [ESIS] A strong eye irritant; May cause skin sensitization; [Alfa Aesar MSDS]

Skin Sens. 1 (100%)

Eye irritation - category 2

Eye Irrit. 2

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

UNTOWARD EFFECTS, INCL MILD ERYTHEMA, DERMATITIS, & ECZEMATOUS REACTIONS, HAVE BEEN REPORTED. ... SYSTEMIC TOXICITY HAS NOT BEEN OBSERVED AFTER ITS LOCAL APPLICATION.

SUMMARY TOXICITY STATEMENT: ACUTE... LOW... LOW= CAUSES READILY REVERSIBLE TISSUE CHANGES WHICH DISAPPEAR AFTER EXPOSURE STOPS; CAUSES SOME DISCOMFORT.

... Many cases of dermatitis and leucoderma that were evidently caused by skin contact with rubber that contained hydroquinone monobenzyl ether as an antioxidant /have been reported/.

... No toxic changes were observed in guinea pigs ingesting this compound at the level of 160 mg/kg daily for 2 months for a total dose of 4.37 g. The only change noted was a depigmentation of the hair.

... No toxic changes were observed in mice that were injected ip with 600 mg/kg of hydroquinone monobenzyl ether daily for 3 weeks.

... A 5 percent concentration of hydroquinone monobenzyl ether in ethanol ... was nonsensitizing /to guinea pigs/.

D - Dermatologicals

QD - Dermatologicals

Monobenzone is the monobenzyl ether of hydroquinone. Monobenzone, applied topically to the skin, is used as a depigmenting agent inhibitting melanin produced by polymerization of oxidation products of tyrosine and dihydroxyphenyl compounds. Monobenzone works by permanently removing color from normal skin located around skin with vitiligo.

Monobenzone is a depigmenting agent whose mechanism of action is not fully understood. It is proposed that it increases the excretion of melanin from the melanocytes. This effect is erratic and may take one to four months to occur while existing melanin is lost with normal sloughing of the stratum corneum. Hyperpigmented skin appears to fade more rapidly than does normal skin, and exposure to sunlight reduces the depigmenting effect of the drug. Following skin depigmentation after topical application of monobenzone, the histological studies indicate similar results as that seen in vitiligo, where the epidermis is intact but with the absence of identifiable melanocytes.

...INTERFERES WITH BIOSYNTHESIS OF MELANIN. IT INHIBITS ENZYME TYROSINASE & THEREBY PREVENTS CONVERSION OF TYROSINE TO DIHYDROXYPHENYLALANINE, PRECURSOR OF MELANIN.

9L2KA76MG5

MONOBENZONE

Physiologic Effects [PE] - Depigmenting Activity

Established Pharmacologic Class [EPC] - Depigmenting Agent

Mechanisms of Action [MoA] - Melanin Synthesis Inhibitors

Monobenzone is a Depigmenting Agent. The mechanism of action of monobenzone is as a Melanin Synthesis Inhibitor. The physiologic effect of monobenzone is by means of Depigmenting Activity.

Used as a solvent and in perfumes, soap, plastics, and pharmaceuticals; [Hawley] Used as an antioxidant (rubber, paraffins, and polyvinyl chloride), stabilizer, polymerization inhibitor, intermediate, and depigmentor to treat hyperpigmentation of the skin; [HSDB]

ANTIOXIDANT FOR PARAFFINS AND POLYVINYL CHLORIDE, POLYPROPYLENE AND POLYPROPYLENE OXIDE; CHEM INT IN ORGANIC SYNTHESIS

Rubber antioxidant, stabilizer, polymerization inhibitor, chemical intermediate.

MEDICATION

MEDICATION (VET)

(1974) PROBABLY GREATER THAN 4.54X10+5 GRAMS

(1975) PROBABLY GREATER THAN 4.54X10+5 GRAMS

REACTION OF SODIUM PHENOXIDE WITH BENZYL CHLORIDE; REACTION OF HYDROQUINONE AND BENZYL BROMIDE IN ALCOHOLIC POTASSIUM HYDROXIDE

PREPD IN VARIOUS WAYS. ONE METHOD INVOLVES CONDENSING SODIUM P-NITROPHENOLATE WITH BENZYL CHLORIDE TO PRODUCE BENZYL P-NITROPHENYL ETHER FOLLOWED BY 1) REDUCTION OF NITRO TO AMINO, 2) DIAZOTIZATION OF AMINO, & 3) HYDROLYTIC DECOMP OF DIAZONIUM CMPD TO CORRESPONDING PHENOL.