Didecylphthalat

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.

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.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 2.0X10+6(SRC), determined from a log Kow of 9.05(2) and a regression-derived equation(3), indicates that didecyl phthalate is expected to be immobile in soil(SRC). Volatilization of didecyl phthalate from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.8X10-5 atm-cu m/mole(SRC), using a fragment constant estimation method(4). However, adsorption to soil is expected to attenuate volatilization(SRC). Didecyl phthalate is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 7.9X10-9 mm Hg(SRC), determined from a fragment constant method(5). Using an inoculum obtained from soil and sewage sludge, didecyl phthalate, as a mixture with dioctyl and dihexyl phthalate, underwent greater than 99% primary biodegradation under aerobic conditions in 28 days(6).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 2.0X10+6(SRC), determined from a log Kow of 9.05(2) and a regression-derived equation(3), indicates that didecyl phthalate is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is expected(3) based upon an estimated Henry's Law constant of 2.8X10-5 atm-cu m/mole(SRC), developed using a fragment constant estimation method(4). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 3.0 and 28 days, respectively(SRC). However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column. The estimated volatilization half-life from a model pond is 600 years if adsorption is considered(5). According to a classification scheme(6), an estimated BCF of 3(SRC), from its log Kow(2) and a regression-derived equation(7), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Estimated hydrolysis half-lives of 7.7 years and 280 days at pHs 7 and 8, respectively, suggest that hydrolysis is not expected to be an important process(8). Didecyl phthalate, present at 1 ug/L, had a half-life of 1.4 days in a river die-away test(9). Didecyl phthalate underwent 1% biodegradation after 15 days using a settled domestic wastewater inoculum, and approximately 10% biodegradation in 15 days after the inoculum was acclimated to this compound(10).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), didecyl phthalate, which has an estimated vapor pressure of 7.9X10-9 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely in the particulate phase in the ambient atmosphere. Particulate-phase didecyl phthalate may be removed from the air by wet or dry deposition(SRC). Didecyl phthalate does contain chromophores that absorb at wavelengths >290 nm(3) and therefore may be susceptible to direct photolysis by sunlight(SRC).

/AQUATIC SPECIES/ The extensive database of acute and chronic aquatic toxicity data for 18 phthalate esters was reviewed and summarized for freshwater and saltwater aquatic microorganisms, algae, invertebrates, and fish. Phthalate esters have been tested with six species of microorganisms, including bacteria and protozoans. Fifteen algal species have been tested, including green and bluegreen algae in both freshwater and saltwater. Nineteen freshwater and saltwater invertebrate species inhabiting surface waters and sediments and 21 freshwater and saltwater fish inhabiting cold and warm water bodies have been tested. The results of most studies indicate that acute and chronic toxicity to microorganisms, algae, aquatic invertebrates, and fish are limited to the lower molecular weight phthalate esters (i.e., dimethyl-, diethyl-, diallyl-, dipropyl-, dibutyl-, diisobutyl-, and butylbenzylphthalate). In contrast, higher molecular weight phthalate esters are not acutely or chronically toxic to aquatic organisms. Although conflicting data on chronic effects for high molecular weight phthalate esters have been reported for daphnids, these inconsistencies are attributed to physical effects imposed on daphnids when exposed to test concentrations in excess of true water solubilities. Altogether, nearly 400 test results covering more than 60 species of microorganisms, algae, invertebrates, and fish are reported for both freshwater and saltwater aquatic species. While most investigators used several common species and standard protocols to assay conventional endpoints, many nontraditional species and toxicological endpoints were also used. This has created a toxicological database of both sufficient depth to compare many similar tests and sufficient breadth to encompass virtually al important types of aquatic habitats and classes of aquatic species.

The Koc of didecyl phthalate is estimated as 2.0X10+6(SRC), using a log Kow of 9.05(1) and a regression-derived equation(2). According to a classification scheme(3), this estimated Koc value suggests that didecyl phthalate is expected to be immobile in soil.

/OTHER TOXICITY INFORMATION/ To compare changes in platelets stored in the new di-n-decyl phthalate (DnDP)-plasticized polyvinyl chloride (PVC) bag with those in a di-(2-ethylhexyl)phthalate (DEHP)-plasticized PVC bag, a single-donor apheresis platelet concentrates (PCs), 133 +/- 11 x 10(7) platelets per mL (n=7), were stored with 94 +/- 3 mL of plasma in a new 1-liter bag with a surface area of 44 +/- 7.1 sq cm per 10(10) platelets. Oxygen and carbon dioxide gas diffusion properties of PVC-DnDP films were respectively, 1.6 and 2 times those of standard PVC-di-(2-ethylhexyl)phthalate films. The amounts of DnDP leaked into the plasma of PCs were low at 0.58 +/- 0.06 mg per bag after 5-day storage, which is about 1/80 the amount of di-(2-ethylhexyl)phthalate leaked. The pH of PCs in PVC-DnDP bags amounted to 6.99 +/- 0.03 after 5-day storage, with glycolysis accelerated somewhat in the new bags. However, the platelet oxygen consumption was no different from that in the PVC-di-(2-ethylhexyl)phthalate bags. Platelet aggregation and response to hypotonic shock were significantly better in the new bags at the end of storage. Shape changes of platelets into spherical forms with dendrites were more frequently observed in PVC-DnDP bags than in PVC-di-(2-ethylhexyl)phthalate bags. The study indicated that platelets stored in the new DnDP-plasticized PVC bags have retained aggregation and response to hypotonic shock more than platelets in the PVC-di-(2-ethylhexyl)phthalate bags, but spherical forms and anaerobic metabolism increased in the new bags.

AEROBIC: Didecyl phthalate underwent 1% biodegradation after 15 days using a settled domestic wastewater inoculum, and approximately 10% biodegradation in 15 days after the inoculum was acclimated to this compound(1). Didecyl phthalate as a mixture with dihexyl and dioctyl phthalate was shown to rapidly biodegrade under aerobic conditions in an activated sludge die-away test(2). Using an inoculum obtained from soil and sewage sludge, didecyl phthalate, as a mixture with dioctyl and dihexyl phthalate, underwent greater than 99% primary biodegradation under aerobic conditions in 28 days(3). Didecyl phthalate, present at 1 ug/L, had a half-life of 1.4 days in a river die-away test(4).

ANAEROBIC: Didecyl phthalate biodegradation was not observed after 35-100 days at a starting concn of 20 ug/L(1).

An estimated BCF of 3 was calculated in fish for didecyl phthalate(SRC), using an estimated log Kow of 9.05(1) and a regression-derived equation(2). According to a classification scheme(3), this BCF suggests the potential for bioconcentration in aquatic organisms is low(SRC).

The Henry's Law constant for didecyl phthalate is estimated as 2.8X10-5 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that didecyl phthalate is expected to volatilize from water surfaces(2). 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)(2) is estimated as 3.0 days(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(2) is estimated as 28 days(SRC). However, adsorption to soil is expected to attenuate volatilization(SRC). The volatilization half-life from a model pond is about 600 years when adsorption is considered(3). Didecyl phthalate's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Didecyl phthalate is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 7.9X10-9 mm Hg(SRC), determined from a fragment constant method(4).

/LABORATORY ANIMALS: Acute Exposure/ Didecyl phthalate rated 1 on rabbit eyes. ... Substances ... have been rated numerically on a scale of 1 to 10 according to the degree of injury observed after 24 hr, paying particular attention to the condition of the cornea. The most severe injuries have been rated 10.

/LABORATORY ANIMALS: Acute Exposure/ In investigation of lethal dose for rats, it has been found that single oral dose of 63 mL/kg body weight is not fatal ... .

/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ /Toxicological properties closely resemble those of dinonyl phthalate/ no sign of toxicity was found in chickens ... given doses of 1 mL/kg body weight ... on 5 consecutive days. Daily doses of 2 mL/kg given to cats for 12 wk did not give rise to any physiological or biological disorder ... .

/GENOTOXICITY/ The ability of phthalic acid, phthalic acid anhydride, and various phthalate esters to enhance the mutagenicity of many amino acid pyrolysates was observed with the Ames test (Salmonella typhimurium TA98), but not the SOS Chromotest. Phthalate enhancement of the mutagenicity of 4-nitroquinoline-1-oxide, 2-nitrofluorene, and benzo[a]pyrene was not observed with either test. The mutagenicity-enhancing ability may be related to the induction of enzymes such as P450IIB, that metabolize amino acid pyrolysates. By quantitative structure activity relationship (QSAR) analysis, a good correlation was observed between the mutagenicity-enhancing activity of phthalates and their octanol-water partition coefficients.

/OTHER TOXICITY INFORMATION/ ... Didecylphthalate ... caused an increase in the amount of hepatic cytochrome P-450 when administered intragastrically to rats. No statistically significant increase could be detected in the catalytic activities dependent on cytochrome P-450 (benzo(a)pyrene hydroxylation, ethoxycoumarin deethylation). ...

The rate constant for the vapor-phase reaction of didecyl phthalate with photochemically-produced hydroxyl radicals has been estimated as 2.6X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 15 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). A base-catalyzed second-order hydrolysis rate constant of 0.029 L/mole-sec(SRC) was estimated using a structure estimation method(2); this corresponds to half-lives of 7.7 years and 280 days at pH values of 7 and 8, respectively(2). Didecyl phthalate does contain chromophores that absorb at wavelengths >290 nm(3) and therefore may be susceptible to direct photolysis by sunlight(SRC).