4-Methylanisole

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.

TERRESTRIAL FATE: Based on a recommended classification scheme(1), an estimated Koc value of 670(SRC), determined from an experimental log Kow(2) and a recommended regression-derived equation(3), indicates that 1-methoxy-4-methylbenzene will have low mobility in soil(SRC). Volatilization of 1-methoxy-4-methylbenzene may be important from moist soil surfaces(SRC) given an estimated Henry's Law constant of 4.7X10-3 atm-cu m/mole(4,SRC), and from dry soil surfaces(SRC) based on an estimated vapor pressure of 1.14 mm Hg(5,SRC). Insufficient data are available to determine the rate or importance of biodegradation of 1-methoxy-4-methylbenzene in soil(SRC).

AQUATIC FATE: Based on a recommended classification scheme(1), an estimated Koc value of 670(SRC), determined from an experimental log Kow(2) and a recommended regression-derived equation(3), indicates that 1-methoxy-4-methylbenzene may adsorb to suspended solids and sediment(SRC) in water. 1-Methoxy-4-methylbenzene may volatilize from water surfaces based on an estimated Henry's Law constant of 4.7X10-3 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). Estimated half-lives for a model river and model lake are 3.4 hours and 4.4 days, respectively(3,SRC). An estimated BCF value of 62(3,SRC), from an experimental log Kow(2), suggests that 1-methoxy-4-methylbenzene will only bioconcentrate moderately in aquatic organisms(SRC) according to a recommended classification scheme(5). Insufficient data are available to determine the rate or importance of biodegradation of 1-methoxy-4-methylbenzene in water(SRC).

ATMOSPHERIC FATE: According to a suggested classification scheme(1), an estimated vapor pressure of 1.1 mm Hg at 25 °C(2,SRC) indicates that 1-methoxy-4-methylbenzene will exist in the vapor phase in the ambient atmosphere. Vapor-phase 1-methoxy-4-methylbenzene 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 14 hours(3,SRC).

1-Methoxy-4-methylbenzene has been detected at trace amounts (limit of detection = 0.1 ppb) in a product water sample from a coal gasification site in Hanna, WY(1). 1-Methoxy-4-methylbenzene was qualitatively detected in advanced waste treatment water in Pomona, CA on 9/25/74(2).

The Koc of 1-methoxy-4-methylbenzene is estimated as approximately 670(SRC), using an experimental log Kow of 2.66(1) and a regression-derived equation(2,SRC). According to a recommended classification scheme(3), this estimated Koc value suggests that 1-methoxy-4-methylbenzene has low mobility in soil(SRC).

1-Methoxy-4-methylbenzene's production and use as an synthetic flavor(1), perfume ingredient(2), and as a starting material for the preparation of p-anisaldehyde(3) may result in its release to the environment through various waste streams(SRC).

An estimated BCF value of 62 was calculated for 1-methoxy-4-methylbenzene(SRC), using an experimental log Kow of 2.66(1) and a recommended regression-derived equation(2). According to a recommended classification scheme(3), this BCF value suggests that 1-methoxy-4-methylbenzene will bioconcentrate moderately in aquatic organisms(SRC).

The Henry's Law constant for 1-methoxy-4-methylbenzene is estimated as 4.7X10-3 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This value indicates that 1-methoxy-4-methylbenzene will volatilize from water surfaces(2,SRC). Based on this Henry's Law constant, the volatilization half-life from a model river (1 m deep, flowing 1 m/sec, wind velocity of 3 m/sec) is estimated as approximately 3.4 hours(2,SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec) is estimated as approximately 4.4 days(2,SRC). 1-Methoxy-4-methylbenzene's vapor pressure, 1.1 mm Hg(3,SRC) and Henry's Law constant(1,SRC) indicate that volatilization from dry and moist soil may occur(SRC).

ACUTE DERMAL LD50 IN RABBITS WAS REPORTED AS GREATER THAN 5 G/KG. ...APPLIED FULL STRENGTH ON INTACT OR ABRADED RABBIT SKIN WAS MODERATELY IRRITATING.

4-Methoxytoluene was given by gavage to 4 groups of 20 rats at dosage levels of 0, 40, 120 or 240 mg/kg body wt/day for 4 wk. There was a statistically significant decr in serum creatinine and urea in the intermediate and high dose group for both sexes. Among males, a statistically significant decr in the packed cell volume was observed in the high and intermediate dose group. A no observed effect level of 40 mg/kg body wt/day was determined.

p-Methylanisole is a food additive permitted for direct addition to food for human consumption as a synthetic flavoring substance and adjuvant in accordance with the following conditions: 1) the quantity added to food does not exceed the amount reasonably required to accomplish its intended physical, nutritive, or other technical effect in food, and 2) when intended for use in or on food it is of appropriate food grade and is prepared and handled as a food ingredient.