Methyl-p-benzochinon

log Kow = 0.72

0.67

YELLOW PLATES OR NEEDLES

YELLOW LEAFLETS OR NEEDLES

Slightly soluble in water; soluble in ethanol and ether

Very sol in acetone, ethyl acetate, alcohol, ether, and benzene; soluble in hot water

Warning

H302 (98.2%): Harmful if swallowed [Warning Acute toxicity, oral]

P261, P264, P264+P265, P270, P271, P280, P301+P317, P302+P352, P304+P340, P305+P351+P338, P319, P321, P330, P332+P317, P337+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 55 reports by companies from 6 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Chemical: 2,5-Cyclohexadiene-1,4-dione, 2-methyl-

Methyl-p-benzoquinone: Does not have an individual approval but may be used under an appropriate group standard

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.

WHEN 0.1% SOLN /IN BENZENE/ WAS.../PAINTED ON SKIN/, 41 MICE SURVIVED MORE THAN 200 DAYS, & 6 DEVELOPED SKIN PAPILLOMAS, 2 DEVELOPED SKIN CARCINOMAS & 10 DEVELOPED LUNG ADENOCARCINOMAS... OF 46 SURVIVING CONTROLS TREATED WITH BENZENE, 1 DEVELOPED SKIN PAPILLOMA, & 2 DEVELOPED LUNG ADENOCARCINOMAS... /1,4-BENZOQUINONE/

TERRESTRIAL FATE: Estimated Koc values of 2(1,SRC) and 60(2,SRC), determined from a structure estimation method(1) and an experimental log Kow(3), respectively, indicate that 2-methyl-1,4-benzoquinone may have high to very high mobility in soil(SRC), according to a recommended classification scheme(4). Incomplete information is available regarding 2-methyl-1,4-benzoquinone's potential for biodegradation. 2-Methyl-1,4-benzoquinone, present in wastewater from 1-4 ng/g, was not detected following activated sludge treatment(5,6) suggesting that this compound can be aerobically biodegraded(SRC). Slow volatilization of 2-methyl-1,4-benzoquinone may occur from dry soil surfaces(SRC) based on an estimated vapor pressure of 3.4X10-2 mm Hg(7,SRC); however, it is not expected to be a major fate process from moist soil surfaces(SRC) given a Henry's Law constant of 1.9X10-9 atm-cu m/mole(8,SRC).

AQUATIC FATE: Estimated Koc values of 2(1,SRC) and 60(2,SRC), determined from a structure estimation method(1) and an experimental log Kow(3), respectively, suggest that 2-methyl-1,4-benzoquinone will not adsorb to suspended solids and sediment(SRC) in the water column(2). 2-Methyl-1,4-benzoquinone is not expected to volatilize from water surfaces based on an estimated Henry's Law constant of 1.9X10-9 atm-cu m/mole(SRC), developed using a fragment constant estimation method(5). According to a recommended classification scheme(6), an estimated BCF value of 2(2,SRC), from an experimental log Kow(3), suggests that 2-methyl-1,4-benzoquinone will not bioconcentrate in aquatic organisms(SRC). 2-Methyl-1,4-benzoquinone may not be readily biodegraded as initial wastewater concentrations of 1-4 ng/g were unchanged in final effluents following activated sludge treatment(7).

ATMOSPHERIC FATE: According to a suggested classification scheme(1), an estimated vapor pressure of 3.4X10-2 mm Hg at 25 °C(2,SRC) indicates that 2-methyl-1,4-benzoquinone will exist mainly in the vapor phase in the ambient atmosphere. Vapor-phase 2-methyl-1,4-benzoquinone is degraded in the atmosphere by reaction with photochemically produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be about 29.5 hours(3,SRC).

Using a structure estimation method based on molecular connectivity indices(1), the Koc for 2-methyl-1,4-benzoquinone can be estimated to be about 2(SRC). The Koc of 2-methyl-1,4-benzoquinone is estimated as approximately 60(SRC), using an experimental log Kow of 0.72(2) and a recommended regression-derived equation(3,SRC). According to a suggested classification scheme(4), these estimated Koc values suggest that 2-methyl-1,4-benzoquinone has high to very high mobility in soil(SRC).

ULCERATION OF CORNEA HAS RESULTED FROM ONE BRIEF EXPOSURE TO HIGH CONCN OF VAPOR OF QUINONE, AS WELL AS FROM REPEATED EXPOSURES TO MODERATELY HIGH CONCN. ...RECOVERY OCCURRED PROMPTLY & SPONTANEOUSLY... /1,4-BENZOQUINONE/

CAN CAUSE DERMATITIS WITH DISCOLORATION, ERYTHEMA, FORMATION OF PAPULES & VESICLES. IN SEVERE CASES THERE CAN BE NECROTIC CHANGES IN SKIN. VAPORS ACTING ON EYE CAN CAUSE SERIOUS DISTURBANCES, INCL CONJUNCTIVITIS & EVEN CORNEAL ULCERATION. DISCOLORATION OF CONJUNCTIVA & CORNEA HAVE BEEN REPORTED. /1,4-BENZOQUINONE/

...@ 0.5 PPM VAPORS ARE IRRITATING TO EYES, & @ 3.0 PPM THEY ARE VERY IRRITATING. /1,4-BENZOQUINONE/

Chronic neurotoxic effects include vision disturbances. /From table; Quinones/

The presence of 2-methyl-1,4-benzoquinone in wastewater from a petroleum oil refinery(1) and in retort water from an oil-shale operation(2), suggests that this compound may be released in various waste streams during the extraction and refining of oil(SRC).

An estimated BCF value of 2 was calculated for 2-methyl-1,4-benzoquinone(SRC) using an experimental log Kow of 0.72(1) and a recommended regression-derived equation(2,SRC). According to a suggested classification scheme(3), this BCF value suggests that bioconcentration of 2-methyl-1,4-benzoquinone in aquatic organisms will not be an important fate process(SRC).

The Henry's Law constant for 2-methyl-1,4-benzoquinone is estimated as 1.9X10-9 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This value indicates that 2-methyl-1,4-benzoquinone essentially will not volatilize from water surfaces(2,SRC). 2-Methyl-1,4-benzoquinone's low Henry's Law constant(1,SRC) suggests that volatilization from moist soil surfaces will not occur(SRC). However, this compound's estimated vapor pressure, 3.4X10-2 mm Hg(3,SRC), indicates that volatilization from dry soil surfaces may occur slowly(SRC).

...25 MICE...EXPOSED /BY INHALATION/ TO 5 MG PARA-QUINONE IN 130-L CHAMBER FOR 1 HR, 6 TIMES/WK; 25 MICE WERE UNTREATED... IN 11 TREATED MICE THAT SURVIVED... 100 DAYS, 2 LUNG ADENOCARCINOMAS WERE OBSERVED. AMONG 12 CONTROLS THAT DIED AFTER MORE THAN 100 DAYS, 2 LUNG ADENOMAS WERE OBSERVED. /1,4-BENZOQUINONE/

...24 RATS (15 WISTAR...& 9 HYBRIDS), WEIGHING ABOUT 200 G EACH, WERE INJECTED SC WITH 0.5 ML SOLN OF P-QUINONE IN PROPYLENE GLYCOL @ WEEKLY INTERVALS. CONCN...1ST 53 DAYS WAS 1%...0.2% FROM DAYS 54-173...0.4% AFTER 173 DAYS. 17 RATS SURVIVED...394 DAYS...TOTAL OF 32 INJECTIONS... INJECTION-SITE FIBROSARCOMAS...IN 2 RATS. /1,4-BENZOQUINONE/

ASPHYXIA APPEARS TO PLAY IMPORTANT ROLE IN TERMINAL PICTURE...BECAUSE OF PULMONARY DAMAGE RESULTING FROM EXCRETION OF QUINONE INTO ALVEOLI & BECAUSE OF CERTAIN NOT TOO WELL-DEFINED EFFECTS OF QUINONE UPON HEMOGLOBIN. URINE OF SEVERELY POISONED ANIMALS MAY CONTAIN PROTEIN, BLOOD, CASTS... /1,4-BENZOQUINONE/

ABSORPTION OF LARGE DOSES OF QUINONE FROM GASTROENTERIC TRACT OR FROM SC TISSUES OF ANIMALS INDUCED LOCAL CHANGES, CRYING, CLONIC CONVULSIONS, RESPIRATORY DIFFICULTIES, DROP OF BLOOD PRESSURE, & DEATH BY PARALYSIS OF MEDULLARY CENTERS. /1,4-BENZOQUINONE/

For more Non-Human Toxicity Excerpts (Complete) data for 2-METHYL-1,4-BENZOQUINONE (9 total), please visit the HSDB record page.

The rate constant for the vapor-phase reaction of 2-methyl-1,4-benzoquinone with photochemically produced hydroxyl radicals has been estimated as 1.3X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of approximately 29.5 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1,SRC).

YIELDS METHYLBENZOSEMIQUINONE IN ESCHERICHIA. YIELDS METHYLQUINOL IN PIG; IN PEA; AND IN DESULFOVIBRIO. /FROM TABLE/

Quinones (ie, 6,12-dione) have been shown to undergo oxidation-reduction cycles involving quinone, hydroquinone, and molecular oxygen, resulting in the formation of oxygen radicals and semiquinone radicals. /Quinones/