Dibenzyl ether

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

SMALL SPILLS AND LEAKAGE: If you spill this chemical, FIRST REMOVE ALL SOURCES OF IGNITION. Then, use absorbent paper to pick up all liquid spill material. Your contaminated clothing and absorbent paper should be sealed in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with 60-70% ethanol followed by washing with a soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.

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.

IT WOULD NOT APPEAR THAT DIBENZYL ETHER HAS CAUSED POISONING IN THE FACTORY BUT ITS VOLATILITY...IS RELATIVELY HIGH, & USUAL PROTECTIVE MEASURES MUST BE TAKEN...PROVISION OF GOOD VENTILATION IS MOST IMPORTANT.

SRP: Local exhaust ventilation should be applied wherever there is an incidence of point source emissions or dispersion of regulated contaminants in the work area. Ventilation control of the contaminant as close to its point of generation is both the most economical and safest method to minimize personnel exposure to airborne contaminants.

TERRESTRIAL FATE: Based on a recommended classification scheme(1), an estimated Koc value of 1500(SRC), determined from an experimental log Kow(2) and a recommended regression-derived equation(3), indicates that dibenzyl ether will have slight mobility in soil(SRC). Volatilization of dibenzyl ether is not expected to occur from moist soils, based on an estimated Henry's Law constant of 8.3X10-8 atm-cu m/mol(4) or from dry soils based on an experimental vapor pressure of 1.03X10-3 mm Hg(5). According to a MITI biodegradation test, biodegradation of dibenzyl ether is not expected to be an important fate process in soil(6). However, another study with seawater and river water indicated biodegradation may be rapid(7).

AQUATIC FATE: An estimated Koc value of 1500(SRC), determined from an experimental log Kow(1) and a recommended regression-derived equation(2), indicates that dibenzyl ether would adsorb to suspended solids and sediment(2,SRC) in the water. Dibenzyl ether will be essentially non-volatile from water surfaces based on an estimated Henry's Law constant of 8.3X10-8 atm-cu m/mole(SRC), developed using a fragment constant estimation method(3). Experimental BCF values of 171-429 and 187-345(5) suggest that bioconcentrate of dibenzyl ether will be high aquatic organisms(SRC) according to a classification scheme(4). According to a MITI biodegradation test, biodegradation of dibenzyl ether is not expected to be an important fate process in water(5). However, another study with seawater and river water indicated biodegradation may be rapid(6).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), dibenzyl ether, which has an experimental vapor pressure of 1.03X10-3 mm Hg at 25 °C(2) will exist as a vapor in the ambient atmosphere. Vapor-phase dibenzyl ether 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 18 hours(3,SRC).

The Koc of dibenzyl ether is estimated as approximately 1500(SRC), using an experimental log Kow of 3.31(1) and a regression-derived equation(2,SRC). According to a recommended classification scheme(3), this estimated Koc value suggests that dibenzyl ether has slight mobility in soil(SRC).

Dibenzyl ether's production and use as a synthetic flavoring ingredient(1), a plasticizer for synthetic rubber(2), a plasticizer for nitrocellulose(3) and a solvent in perfumery(3) may result in its release to the environment through various waste streams(SRC).

A two-week biodegradation study using 30 mg/l sludge and a dibenzyl ether concentration of 100 mg/l gave a theoretical BOD of 0%(1). The estimated half-life for dibenzyl ether in Rhine river water (Netherlands) is 0.4 days(2) but this was based upon monitoring data and may include processes other than biodegradation. Biodegradation of dibenzyl ether in river and sea water was 27 and 40%, respectively, after a 3-day cultivation period(3).

An estimated BCF value of 190 was calculated for dibenzyl ether(SRC), using an experimental log Kow of 3.31(1) and a recommended regression-derived equation(2). An 8-week bioconcentration study using carp and dibenzyl ether concentrations of 0.2 mg/l and 0.02 mg/l gave bioconcentration factors of 171-429 and 187-345, respectively(4). According to a classification scheme(3), these experimental BCF values suggest that bioconcentration in aquatic organisms is high(SRC).

The Henry's Law constant for dibenzyl ether is estimated as 8.3X10-8 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This value indicates that dibenzyl ether will be essentially nonvolatile from water surfaces(2,SRC). Dibenzyl ether's vapor pressure, 1.03X10-3 mm Hg(3) and Henry's Law constant(1,SRC) indicate that volatilization from dry and moist soil may not occur(SRC).

The rate constant for the vapor-phase reaction of dibenzyl ether with photochemically produced hydroxyl radicals has been estimated as 2.1X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1,SRC). This corresponds to an atmospheric half-life of about 18 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1,SRC).

DRINKING WATER: Dibenzyl ether was qualitatively identified in Japanese tap water(1).

SURFACE WATER: Dibenzyl ether was identified in the Niagara River watershed at 70 ppm in the 102nd Street Bay area and in Bloody Run Creek water at a level of 0.1-1 ppb(1). Dibenzyl ether was also qualitatively identified in the Niagara River(2). Dibenzyl ether was detected in the River Rhine at three different locations in the Netherlands: Lobith, 0.3 ug/l; Maassluis, 0.01 and 0.1 ug/l; and at Gorinchem, 0.03 ug/l(3).

Dibenzyl ether 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.