Dibutyl phenyl phosphate

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.

Biological Exposure Indices (BEI) [ACGIH] - Acetylcholinesterase activity in red blood cells = 70% of individual's baseline; Butylcholinesterase activity in serum or plasma = 60% of individual's baseline; Sample at end of shift; [TLVs and BEIs]

SMALL SPILLS AND LEAKAGE: If you spill this chemical, 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 alcohol followed by washing with a strong 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: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.

0.3 [ppm]

8 hr Time Weighted Avg (TWA): 0.3 ppm, skin.

Excursion Limit Recommendation: Excursions in worker exposure levels may exceed 3 times the TLV-TWA for no more than a total of 30 minutes during a work day, and under no circumstances should they exceed 5 times the TLV-TWA, provided that the TLV-TWA is not exceeded.

Biological Exposure Index (BEI): Determinant: cholinesterase activity in red blood cells; Sampling Time: discretionary; BEI: 70% of individual's baseline. The determinant is nonspecific, since it is also observed after exposure to other chemicals. /Acetylcholinesterase inhibiting pesticides/

RECOMMENDED RESPIRATOR: Where the neat test chemical is weighed and diluted, wear a NIOSH-approved half face respirator equipped with an organic vapor/acid gas cartridge (specific for organic vapors, HCl, acid gas and SO2) with a dust/mist filter. (NTP, 1992)

Dibutyl phenyl phosphate was not detected (detection limit 1 ng/g) in adipose samples obtained at autopsy from up to eight male and eight female cadavers from each of six municipalities (Cornwall, London, St Catharines, Toronto, Welland, Windsor) in Ontario, Canada(1).

EC50; Species: Daphnia magna (Water Flea) age <24 hr; Conditions: freshwater, static, 20-23 °C, pH 7.0-8.5, hardness 120-250 mg/L CaCO3, alkalinity 120-250 mg/L CaCO3, dissolved oxygen 6.0-9.3 mg/L; Concentration: 450 ug/L for 24 hr; Effect: intoxication, immobilization /formulation/

EC50; Species: Daphnia magna (Water Flea) age <24 hr; Conditions: freshwater, flow through, 21-23 °C, pH 8.0-8.5, hardness 160-180 mg/L CaCO3, alkalinity 122-128 mg/L CaCO3, dissolved oxygen 7.5-8.0 mg/L; Concentration: 260 ug/L for 48 hr; Effect: intoxication, immobilization

EC50; Species: Daphnia magna (Water Flea) age <24 hr; Conditions: freshwater, static, 20-23 °C, pH 7.0-8.5, hardness 120-250 mg/L CaCO3, alkalinity 120-250 mg/L CaCO3, dissolved oxygen 6.0-9.3 mg/L; Concentration: 360 ug/L for 48 hr; Effect: intoxication, immobilization /formulation/

EC50; Species: Daphnia magna (Water Flea) age <24 hr; Conditions: freshwater, flow through, 21-23 °C, pH 8.0-8.5, hardness 160-180 mg/L CaCO3, alkalinity 122-128 mg/L CaCO3, dissolved oxygen 7.5-8.0 mg/L; Concentration: 230 ug/L for 7 days; Effect: intoxication, immobilization

For more Ecotoxicity Values (Complete) data for DIBUTYL PHENYL PHOSPHATE (6 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 930(SRC), determined from a structure estimation method(2), indicates that dibutyl phenyl phosphate is expected to have low mobility in soil(SRC). Volatilization of dibutyl phenyl phosphate from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 5.0X10-7 atm-cu m/mole(SRC), using a fragment constant estimation method(2). Dibutyl phenyl phosphate is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 1.4X10-5 mm Hg at 25 °C(SRC), determined from a fragment constant method(2). Biodegradation may be the dominant fate process of dibutyl phenyl phosphate in soil(SRC); a screening test exhibited an aerobic half-life of about 3.5 days or less in natural waters(3).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 930(SRC), determined from a structure estimation method(2), indicates that dibutyl phenyl phosphate is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 5.0X10-7 atm-cu m/mole(SRC), developed using a fragment constant estimation method(2). Dibutyl phenyl phosphate is not expected to undergo hydrolysis in the environment(SRC) due to estimated hydrolysis half-lives of 3.6 to 47 years at pH 9 to 5(2). According to a classification scheme(4), an estimated BCF of 46(SRC), from its log Kow of 4.27(5) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is moderate(SRC). Biodegradation is an important removal process in aerobic waters with a half-life of 3.5 days or less(6).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), dibutyl phenyl phosphate, which has an estimated vapor pressure of 1.4X10-5 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), will exist in both the vapor and particulate phases in the ambient atmosphere. Vapor-phase dibutyl phenyl phosphate 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 6.5 hours(SRC), calculated from its rate constant of 5.93X10-11 cu cm/molecule-sec at 25 °C(3). Particulate-phase dibutyl phenyl phosphate may be removed from the air by wet and dry deposition(SRC). Dibutyl phenyl phosphate does not contain chromophores that absorb at wavelengths >290 nm(4) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(SRC).

IDENTIFICATION AND USE: Dibutyl phenyl phosphate is a clear slightly yellow liquid. It is used in fire-resistant aircraft hydraulic fluids. HUMAN EXPOSURE AND TOXICITY: It produced marked pain in the eyes following contact; however, such contact has not been reported to cause damage to the eyes. Skin irritation has been described after prolonged skin contact. Exposure to aerosols or vapors produced nose and throat irritation accompanied by coughing and wheezing. ANIMAL STUDIES: It was not irritating to the eye in rabbits, but produced skin irritation upon repeated skin contact in the same species. It caused significant reduction of plasma cholinesterase activity in rabbits and in rats after prolonged exposure. The chemical did not cause organophosphorus compound-induced delayed neurotoxicity (OPIDN) in the adult hen. No teratogenic or fetotoxic effects were observed in the offspring of rats administered dibutyl phenyl phosphate by gavage. No mutagenic activity was seen when dibutyl phenyl phosphate was evaluated in the following systems: microbial assays with five Salmonella strains and one strain of Saccharomyces yeast, in vitro induction of L5178Y TK mouse lymphoma cells, and a hepatocyte primary culture/DNA repair assay. It was not mutagenic in Chinese hamster ovary (CHO) cells.

The following link will take the user to the National Toxicology Program (NTP) Test Agent Search Results page, which tabulates all of the "Standard Toxicology & Carcinogenesis Studies", "Developmental Studies", and "Genetic Toxicity Studies" performed with this chemical. Clicking on the "Testing Status" link will take the user to the status (i.e., in review, in progress, in preparation, on test, completed, etc.) and results of all the studies that the NTP has done on this chemical.[Available from, as of September 2, 2014: http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=ntpsearch.searchresults&searchterm=2528-36-1]

Using a structure estimation method based on molecular connectivity indices(1), the Koc of dibutyl phenyl phosphate can be estimated to be 930(SRC). According to a classification scheme(2), this estimated Koc value suggests that dibutyl phenyl phosphate is expected to have low mobility in soil.

/SIGNS AND SYMPTOMS/ Formulations of dibutyl phenyl phosphate have been reported to produce marked pain in the eyes following contact; however, such contact has not been reported to cause damage to the eyes. Irritation in the form of drying and cracking of exposed skin has been caused by repeated or prolonged skin contact. Exposure to aerosolized dibutyl phenyl phosphate formulations or to vapors of the dibutyl phenyl phosphate formulations at high temperatures has been reported to produce nose and throat irritation accompanied by coughing and wheezing. Dibutyl phenyl phosphate is not considered to be a primary irritant or a sensitizing agent based on patch testing of 50 human volunteers.

AEROBIC: Dibutyl phenyl phosphate, present at 19.7 ppm, reached 61.5 and 84.4% of theoretical CO2 evolution in a CO2-Evolution screening study using acclimated seed (14 day acclimation period) over an incubation period of 7 and 28 days, respectively. In similar experiments, dibutyl phenyl phosphate at initial concentration of 20.6 ppm, reached 11.1, 75.6, and 84.5% of theoretical CO2 evolution in incubation periods of 7, 28, and 48 days, respectively. Dibutyl phenyl phosphate biodegraded 52 and 95% at an addition rate of 13 and 3 mg/L-24 hrs, respectively, in semicontinuous activated sludge (SCAS) tests run at 4 and 21 weeks, respectively. At an initial concentration of 1 ppm, dibutyl phenyl phosphate had a half-life of about 3.5 days in a river die-away test(1).

An estimated BCF of 46 was calculated in fish for dibutyl phenyl phosphate(SRC), using a log Kow of 4.27(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is moderate(SRC).

The Henry's Law constant for dibutyl phenyl phosphate is estimated as 5.0X10-7 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that dibutyl phenyl phosphate is expected to be essentially nonvolatile from water and moist soil surfaces(2). Dibutyl phenyl phosphate is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 1.4X10-5 mm Hg(SRC), determined from a fragment constant method(1).

Pursuant to section 8(d) of TSCA, EPA promulgated a model Health and Safety Data Reporting Rule. The section 8(d) model rule requires manufacturers, importers, and processors of listed chemical substances and mixtures to submit to EPA copies and lists of unpublished health and safety studies. Phosphoric acid, dibutyl phenyl ester is included on this list. Effective date: 10/04/82; Sunset date: 10/04/92.