도데칸메틸펜타실로센

Suitable extinguishing media: For small (incipient) fires, use media such as "alcohol" foam, dry chemical as far as possible. Use very large quantities (flooding) of water applied ineffective. Cool all affected containers with flooding quantities of water. Advice for firefighters: Wear self-contained breathing apparatus for firefighting if necessary. Further information: Use water spray to cool unopened containers.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Remove all sources of ignition. Evacuate personnel to safe areas. Beware of vapors accumulating to form explosive concentrations. Vapors can accumulate in low areas. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Methods and materials for containment and cleaning up: Contain spillage, and then collect with an electrically protected vacuum cleaner or by wet-brushing and place in container for disposal according to local regulations. Keep in suitable, closed containers for disposal.

SRP: 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 air, soil or water; effects on animal, aquatic and plant life; and conformance with environmental and public health regulations. If it is possible or reasonable use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination.

Product: This combustible material may be burned in a chemical incinerator equipped with an afterburner and scrubber. Offer surplus and non-recyclable solutions to a licensed disposal company. Contaminated packaging: Dispose of as unused product.

Gloves must be inspected prior to use. Use proper glove removal technique (without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands.

Avoid contact with skin and eyes. Avoid inhalation of vapor or mist. Keep away from sources of ignition. No smoking. Take measures to prevent the build up of electrostatic charge.

ACCIDENTAL RELEASE MEASURES: Personal precautions, protective equipment and emergency procedures: Use personal protective equipment. Avoid breathing vapors, mist or gas. Ensure adequate ventilation. Remove all sources of ignition. Evacuate personnel to safe areas. Beware of vapors accumulating to form explosive concentrations. Vapors can accumulate in low areas. Environmental precautions: Prevent further leakage or spillage if safe to do so. Do not let product enter drains.

Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday.

Skin protection: Handle with gloves.

Body Protection: Impervious clothing. The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace.

Respiratory protection: Where risk assessment shows air-purifying respirators are appropriate use a full-face respirator with multipurpose combination (US) or type ABEK (EN 14387) respirator cartridges as a backup to engineering controls. If the respirator is the sole means of protection, use a full-face supplied air respirator. Use respirators and components tested and approved under appropriate government standards such as NIOSH (US) or CEN (EU).

Eye/face protection: Safety glasses with side-shields conforming to EN 166. Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU).

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 1.1X10+6(SRC), determined from a structure estimation method(2), indicates that dodecamethylpentasiloxane is expected to be immobile in soil(SRC). Volatilization of dodecamethylpentasiloxane from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 320 atm-cu m/mole(SRC), based upon its vapor pressure, 4.5X10-2 mm Hg(3), and water solubility, 7.0X10-5 mg/L(4). However, adsorption to soil is expected to attenuate volatilization(SRC). Dodecamethylpentasiloxane is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(3). Biodegradation data in soil were not available(SRC, 2018).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 1.1X10+6(SRC), determined from a structure estimation method(2), indicates that dodecamethylpentasiloxane 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 320 atm-cu m/mole(SRC), derived from its vapor pressure, 4.50X10-2 mm Hg(4), and water solubility, 7.04X10-5 mg/L(5). Using this Henry's Law constant and an estimation method(3), volatilization half-lives for a model river and model lake are 6 hrs and 8 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 29 yrs if adsorption is considered(7). According to a classification scheme(6), an estimated BCF of 880(SRC), from its log Kow of 9.41(8) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is high(SRC). Biodegradation data in water were not available(SRC, 2018).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), dodecamethylpentasiloxane, which has an extrapolated vapor pressure of 4.50X10-2 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase dodecamethylpentasiloxane 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 9 days(SRC), calculated from its rate constant of 1.8X10-12 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(3). Dodecamethylpentasiloxane 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: Dodecamethylpentasiloxane is used as a basis for silicone oils or fluids designed to withstand extremes of temperature. It is also used as a foam suppressant in petroleum lubricating oil. HUMAN STUDIES: There are no data available. ANIMAL STUDIES: No signs of dermal irritation, erythema and edema were seen at any scoring interval throughout the study on any animal. No toxic effects were observed when the test material was applied to the skin of rats for 24 hours at 2000 mg/kg bw. In a 28-day study no biologically significant, treatment-related effects were reported in rats given dodecamethylpentasiloxane by oral gavage at 25, 250 or 1000 mg/kg bw/day. It was negative in genotoxicity study with and without activation in Chinese hamster V79 cells. Gene mutation (Bacterial reverse mutation assay / Ames test) assay was negative with and without activation in Salmonella typhimurium strains TA98, TA100, TA1535 and TA1537 and Escherichia coli WP2 uvr A. Mutagenicity test to mammalian cells was negative with and without activation in L5178Y cells. ECOTOXICITY STUDIES: A 21-day EC50 of >47 ng/L and NOEC of >/=47 ng/L have been determined for the effects of the test substance on adult mortality, reproduction and growth of Daphnia magna. A 96-hour LC50 value of >75 ng/L has been determined for effects on mortality of Oncorhynchus mykiss.

/AQUATIC SPECIES/ A 21-day EC50 of >47 ng/L and NOEC of >/=47 ng/L have been determined for the effects of the test substance on adult mortality, reproduction and growth of Daphnia magna. The data have been obtained in flow-through tests and are expressed relative to mean measured concentrations of the substance.

/AQUATIC SPECIES/ A 96-hour LC50 value of >75 ng/L has been determined for effects on mortality of Oncorhynchus mykiss based on mean measured concentrations of the substance in a flow-through test. There are no short-term toxicity data for aquatic invertebrates and algae.

Using a structure estimation method based on molecular connectivity indices(1), the Koc of dodecamethylpentasiloxane can be estimated to be 1.13X10+6(SRC). An estimated log Koc of 5.54 (Koc 3.5X10+5) has also been reported(2). According to a classification scheme(3), these estimated Koc values suggest that dodecamethylpentasiloxane is expected to be immobile in soil(SRC).

URBAN/SUBURBAN: Dodecamethylpentasiloxane was detected at a mean concentration of 1.9 ng/cu cm (range of 0.7-4.8 ng/cu m) in 70 ambient air samples over Toronto, Ontario, Canada, analyzed from March 30 to October 13, 2010(1).

RURAL/REMOTE: Dodecamethylpentasiloxane was present at a mean concentration of 0.013 ng/cu m (range of <0.003-0.033 ng/cu m) in air samples from Aspvreten, Sweden, southwest of Stokholm. Sampling was conducted from Nov 4 to Dec 14, 2011; detection limit = 8.9 pg/cu m(1). A median concentration of 0.043 ng/cu m over 90 days (March 31-July 1, 2009) was reported for samples from Malin Head, Ireland; instrument detection limit = 0.00049 ng/cu m(2).

SOURCE DOMINATED: Dodecamethylpentasiloxane was detected not quantified in biogas generated from two domestic waste disposal sites in Augsburb and Munich Germany. It was present at <0.05 mg/cu m in biogas generated by 2 sewage treatment plants in Munich Germany(1).

Volatile dimethylsiloxanes are a family of synthetic organosilicon-compounds, which have received rising attention because of their widespread use and occurrence in the environment. In the present work, an analytical method based on ultrasound-assisted solid-liquid extraction (USAE) followed by gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) has been optimized and applied to assess the presence of eight volatile dimethyl siloxanes (VMS) (hexamethylcyclotrisiloxane (D3), octamethylcyclotetra-siloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), octamethyltrisiloxane (MDM), decamethyltetrasiloxane (MD2M) and dodecamethylpentasiloxane (MD3M) and tetradecamethylhexasiloxane (MD4M)) in fish. The optimized method presented limits of quantification between 0.1 and 1.3 pg/g for linear volatile dimethylsiloxanes (lVMS) and between 13 and 39 pg/g for cyclic volatile dimethylsiloxanes (cVMS) and intraday relative standard deviation (between 1.9 and 7.0%). Recovery yields were between 71 and 92%. 40 fish samples collected in different markets in Barcelona, (Spain), and 16 samples of fish directly collected at the Xuquer River were analysed. cVMS were detected in almost all the river fish samples at concentrations between pg/g and ng/g, with a significant correlation between the fat content and VMS concentrations in fish. In addition, significant higher concentrations were found in market samples, suggesting sources of contamination from their manipulation and storage in indoor environments. Multivariate analyses were applied to the results and the siloxane profiles and analyte correlations are discussed.

Dodecamethylpentasiloxane's production and use as a basis for silicone oils or fluids designed to withstand extremes of temperature and as a foam suppressant in petroleum lubricating oil(1) may result in its release to the environment through various waste streams(SRC).

An estimated BCF of 880 was calculated in fish for dodecamethylpentasiloxane(SRC), using a log Kow of 9.41(1) and a regression-derived equation(2). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is high(SRC).

The Henry's Law constant for dodecamethylpentasiloxane is estimated as 3.2X10+2 atm-cu m/mole(SRC) derived from its vapor pressure, 4.50X10-2 mm Hg(1), and water solubility, 7.04X10-5 mg/L(2). This Henry's Law constant indicates that dodecamethylpentasiloxane is expected to volatilize rapidly from water surfaces(3). 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)(3) is estimated as 6 hours(SRC). The volatilization half-life from a model lake (1 m deep, flowing 0.05 m/sec, wind velocity of 0.5 m/sec)(3) is estimated as 8 days(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 29 yrs if adsorption is considered(4). Dodecamethylpentasiloxane's estimated Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC). Dodecamethylpentasiloxane is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure(1).

/LABORATORY ANIMALS: Acute Exposure/ No signs of dermal irritation, erythema and edema were seen at any scoring interval throughout the study on any animal. There were also no notable lesions or any additional dermal findings noted during experimental phase /Animal species not stated/.

/LABORATORY ANIMALS: Acute Exposure/ In a GLP study conducted according to OECD Test Guideline 402, no toxic effects were observed when the test material was applied to the skin of rats for 24 hours at 2000 mg/kg bw. The LD50 value was determined to be greater than 2000 mg/kg bw. There were no mortalities, all animals appeared normal throughout the study, no significant macroscopic findings were noted.

/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ In a 28-day study performed according to OECD Test Guideline 407 (DCC, 2010), no biologically significant, treatment-related effects were reported in rats given dodecamethylpentasiloxane (L5) by oral gavage at 25, 250 or 1000 mg/kg bw/day. A NOAEL of >/=1000 mg/kg bw/day was derived.

/GENOTOXICITY/ Cytogenicity study - negative with and without activation in Chinese hamster V79 cells (OECD 473)

For more Non-Human Toxicity Excerpts (Complete) data for Dodecamethylpentasiloxane (6 total), please visit the HSDB record page.

Section 8(a) of TSCA requires manufacturers of this chemical substance to report preliminary assessment information concerned with production, exposure, and use to EPA as cited in the preamble in 51 FR 41329. Effective date: 10/12/93; Reporting date: 2/28/94.

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. Dodecamethylpentasiloxane is included on this list. Effective date: 10/12/93; Sunset date: 6/30/98.