Dibutylhydrogenphosphat

Excerpt from ERG Guide 153 [Substances - Toxic and/or Corrosive (Combustible)]:

Use powder, AFFF, foam, carbon dioxide.

Fresh air, rest.

Remove contaminated clothes. Rinse and then wash skin with water and soap.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth. Do NOT induce vomiting. Give one or two glasses of water to drink. Refer for medical attention .

Excerpt from NIOSH Pocket Guide for Dibutyl phosphate:

(General first aid procedures)

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure 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, aquatic, and plant life; and conformance with environmental and public health regulations.

Personal protection: filter respirator for organic gases and vapours adapted to the airborne concentration of the substance. Collect leaking and spilled liquid in sealable containers as far as possible. Cautiously neutralize spilled liquid. Then wash away with plenty of water.

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

The worker should immediately wash the skin when it becomes contaminated.

Work clothing that becomes wet or significantly contaminated should be removed and replaced.

SRP: Contaminated protective clothing should be segregated in such a manner so that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. Quality assurance to ascertain the completeness of the cleaning procedures should be implemented before the decontaminated protective clothing is returned for reuse by the workers. Contaminated clothing should not be taken home at end of shift, but should remain at employee's place of work for cleaning.

LC50 Daphnia magna (Water flea) 210 mg/L/24 hr

LC50 Oryzias latipes /(Japanese rice fish)/ 110 mg/L/72 hr

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 490(SRC), determined from a water solubility of 1.72X10+4 mg/L(2) and a regression-derived equation(3), indicates that dibutyl phosphate is expected to have moderate mobility in soil(SRC). The pKa of dibutyl phosphate is 0.88(4), indicating that this compound will primarily exist in anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts(5). Volatilization of dibutyl phosphate from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 4.3X10-9 atm-cu m/mole(SRC), using a fragment constant estimation method(6). Dibutyl phosphate is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 3.8X10-5 mm Hg(SRC), determined from a fragment constant method(7).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 490(SRC), determined from a water solubility of 1.72X10+4 mg/L(2) and a regression-derived equation(3), indicates that dibutyl 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 4.3X10-9 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). The estimated pKa of dibutyl phosphate is 0.88(5), indicating that this compound will primarily exist as an anion in the environment and anions generally do not adsorb more strongly to organic carbon than their neutral counterparts(6). The sorption of organophosphorus compounds in soil depends on both organic matter and clay content of soil and the sorption increases as the pH of soil decreases(7), therefore, adsorption to suspended solids and sediments is expected to be pH dependent. According to a classification scheme(8), an estimated BCF of 66(SRC), from a measured water solubility(2) and a regression-derived equation(9), suggests the potential for bioconcentration in aquatic organisms is moderate(SRC). Dibutyl phosphate, present at 4.4 mg/L, reached 12% of its theoretical oxygen demand in 28 days using a municipal sludge inoculum in a closed bottle test(10).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), dibutyl phosphate, which has an estimated vapor pressure of 3.8X10-5 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 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 7.3 hours(SRC), calculated from its rate constant of 5.3X10-11 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Particulate-phase dibutyl phosphate may be removed from the air by wet or dry deposition(SRC). Dibutyl phosphate does not contain chromophores that absorb at wavelengths >290 nm and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

The substance can be absorbed into the body by inhalation of its aerosol.

inhalation, ingestion, skin and/or eye contact

Cough. Headache. Sore throat.

Redness. Pain.

Redness. Pain.

Abdominal pain. Burning sensation. Sore throat.

irritation eyes, skin, respiratory system; headache

The Koc of dibutyl phosphate is estimated as 490(SRC), using a water solubility of 1.72X10+4 mg/L(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that dibutyl phosphate is expected to have moderate mobility in soil. The estimated pKa of dibutyl phosphate is 0.88(4), indicating that this compound will primarily exist in anion form in the environment and anions generally do not adsorb more strongly to organic carbon and clay than their neutral counterparts(5). The sorption of organophosphorus compounds in soil depends on both organic matter and clay content of soil and the sorption increases as the pH of soil decreases(6).

/SIGNS AND SYMPTOMS/ Some workers exposed to dibutyl phosphate have complained of respiratory tract irritation and headache.

/SIGNS AND SYMPTOMS/ Dibutyl phosphate may cause irritation of the eyes, nose, throat, and lungs. It may also cause headaches. Repeated or prolonged exposure to dibutyl phosphate may cause irritation of the skin.

An estimated BCF of 66 was calculated for dibutyl phosphate(SRC), using a water solubility of 1.72X10+4 mg/L(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), provided the compound is not metabolized by the organism(SRC).

The Henry's Law constant for dibutyl phosphate is estimated as 4.3X10-9 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that dibutyl phosphate is expected to be essentially nonvolatile from water surfaces(2). Dibutyl phosphate's Henry's Law constant indicates that volatilization from moist soil surfaces is not expected(SRC). Dibutyl phosphate is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 3.8X10-5 mm Hg(SRC), determined from a fragment constant method(3).

Section 8(a) of TSCA requires manufacturers of this chemical substance to report preliminary assessment information concerned with production, use, and exposure to EPA as cited in the preamble in 51 FR 41329.

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 acid is included on this list.