Dodecamethylpentasiloxane

384.841

384.84

205-492-2

0QDQ2VQ5YJ

DTXSID1044803

Colorless liquid|Liquid

2934999090

36.9

4.72

Liquid

0.876 g/cm³

-80 °C

232 °C

187 °F

n 20/D 1.392(lit.)

3.90e-04 g/l

Keep container tightly closed in a dry and well-ventilated place. Containers which are opened must be carefully resealed and kept upright to prevent leakage. Storage class (TRGS 510): 10: Combustible liquids.

<1 mm Hg ( 20 °C)

Henry's Law constant = 3.24X10+2 atm-cu m/mol at 25 °C (est)

Stable. Inert to most chemical reagents and rubber|Hydroxyl radical reaction rate constant = 1.80X10-12 cu cm/molec-sec at 25 °C (est)

50.3 kJ/mol

NA 1993 / PGIII

3

R36/37/38

26-36

SB0970000

Xi

Stable under recommended storage conditions.

P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501

H315

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.

|Warning|H315 (100%): Causes skin irritation [Warning Skin corrosion/irritation]|P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, and P501|Aggregated GHS information provided by 238 companies from 2 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.|H227: Combustible liquid [Warning Flammable liquids]|P210, P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P370+P378, P403+P233, P403+P235, P405, and P501

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).

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.

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.

Dodecamethylpentasiloxane was detected, not quantified in pre-aeration wastewater sampled from a Singapore wastewater treatment plant(1).

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).

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.

LD50 Rat dermal >2000 mg/kg bw

/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.

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).

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).

Dodecamethylpentasiloxane is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions(1). Dodecamethylpentasiloxane does not contain chromophores that absorb at wavelengths >290 nm(1) and, therefore, is not expected to be susceptible to direct photolysis by sunlight(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).

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).

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).

According to the 2016 TSCA Inventory Update Reporting data, 3 reporting facilities estimate the number of persons reasonably likely to be exposed during the manufacturing, processing, or use of dodecamethylpentasiloxane in the United States may be as low as 10 workers and as high as 50 workers per plant; the data may be greatly underestimated due to confidential business information (CBI) or unknown values(1).|Occupational exposure to dodecamethylpentasiloxane may occur through inhalation and dermal contact with this compound at workplaces where dodecamethylpentasiloxane is produced or used. Limited monitoring data indicate that the general population may be exposed to dodecamethylpentasiloxane via inhalation of ambient air and dermal contact with a limited number of personal care products containing this compound. (SRC)|BACKGROUND: Low molecular weight siloxanes are used in industrial processes and consumer products, and their vapors have been detected in the atmospheres of the Space Shuttle and International Space Station. Therefore, the National Aeronautics and Space Administration (NASA) developed spacecraft maximum allowable concentrations (SMACs) for siloxane vapors to protect astronaut health. Since publication of these original SMACs, new studies and new risk assessment approaches have been published that warrant re-examination of the SMACs. OBJECTIVE: To reevaluate SMACs published for octamethyltrisiloxane (L3) for exposures ranging from 1 hour to 180 days, to develop a 1000-day SMAC, and to expand the applicability of those values to the family of linear siloxanes. METHODS: A literature review was conducted to identify studies conducted since the SMACs for L3 were set in 1994. The updated data were reviewed to determine the sensitive toxicity endpoints, and current risk assessment approaches and methods for dosimetric adjustments were evaluated. RESULTS: Recent data were used to update the original 1-hour, 24-hour, 30-day, and 180-day SMACs for L3, and a 1000-day SMAC was developed to protect crewmembers during future exploration beyond Earth orbit. Group SMACs for the linear siloxane family, including hexamethyldisiloxane (L2), L3, decamethyltetrasiloxane (L4), and dodecamethylpentasiloxane (L5), were set for exposures of 1-hour to 1000 days. CONCLUSION: New SMACs, based on acute pulmonary and neurotoxicity at high doses only achievable with L2 and potential liver effects following longer-term exposures to L2 and L3, were established to protect crewmembers from the adverse effects of exposure to linear siloxanes.

/SRP:/ Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR if necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Poisons A and B/|/SRP:/ Basic treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Watch for signs of respiratory insufficiency and assist ventilations if needed. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 mL/kg up to 200 mL of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . Cover skin burns with dry sterile dressings after decontamination ... . /Poisons A and B/|/SRP:/ Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Consider administering a beta agonist such as albuterol for severe bronchospasm ... . Monitor cardiac rhythm and treat arrhythmias as necessary ... . Start IV administration of D5W TKO /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's (LR) if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... . Treat seizures with diazepam (Valium) or lorazepam (Ativan) ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Poisons A and B/

All other basic inorganic chemical manufacturing|Pentasiloxane, 1,1,1,3,3,5,5,7,7,9,9,9-dodecamethyl-: ACTIVE|Silicone fluids are used as damping fluids, dielectric fluids, polishes, cosmetic and personal care additives, textile finishes, hydraulic fluids, paint additives, photocopy fuser oils, and heat-transfer oils. /Silicone fluids/

We have developed a sensitive method for the detection, characterization, and quantitation of low molecular weight silicones using gas chromatography coupled with atomic emission detection (GC/AED) and gas chromatography/ mass spectrometry (GC/MS). Using this approach, we have detected 12 distinct silicon-containing peaks in PDMS-V poly(dimethylsiloxane) oil by GC/AED, and we have used GC/MS analysis to identify some of the abundant peaks by MS spectral matching. Polydimethylpolysiloxanes contain 37.8% silicon; therefore, the amount of poly(dimethylsiloxane) in each peak can be calculated from its silicon content. The first three GC peaks from PDMS-V were identified as dodecamethylpentasiloxane, tetradecamethylhexasiloxane, and hexadecamethylheptasiloxane using Wiley Mass Spectral Library match (> 90%). Peaks 4-12 could not be matched unequivocally with the spectral library but showed ionic fragments characteristic of PDMS (73, 147, 221, 281, 295, and 369 amu). The detection limit for silicones using GC/AED and GC/MS systems was found to be 80 and 10 pg/uL, respectively. Studies were conducted using mouse liver homogenates spiked with varying amounts of PDMS-V, and the recovery was found to be greater than 90% over a wide range of PDMS-V concentrations. This method appears to work equally well for both linear and cyclic poly(dimethylsiloxane)s. Thus, the methodology described here has the potential to allow the measurement of less than 1 microgram of silicone/g of biological tissue. The overall goal of this research is to establish and validate a methodology by which the unequivocal identification and quantitation of poly(dimethylsiloxane)s can be accomplished.

We have developed a sensitive method for the detection, characterization, and quantitation of low molecular weight silicones using gas chromatography coupled with atomic emission detection (GC/AED) and gas chromatography/ mass spectrometry (GC/MS). Using this approach, we have detected 12 distinct silicon-containing peaks in PDMS-V poly(dimethylsiloxane) oil by GC/AED, and we have used GC/MS analysis to identify some of the abundant peaks by MS spectral matching. Polydimethylpolysiloxanes contain 37.8% silicon; therefore, the amount of poly(dimethylsiloxane) in each peak can be calculated from its silicon content. The first three GC peaks from PDMS-V were identified as dodecamethylpentasiloxane, tetradecamethylhexasiloxane, and hexadecamethylheptasiloxane using Wiley Mass Spectral Library match (> 90%). Peaks 4-12 could not be matched unequivocally with the spectral library but showed ionic fragments characteristic of PDMS (73, 147, 221, 281, 295, and 369 amu). The detection limit for silicones using GC/AED and GC/MS systems was found to be 80 and 10 pg/microL, respectively. Studies were conducted using mouse liver homogenates spiked with varying amounts of PDMS-V, and the recovery was found to be greater than 90% over a wide range of PDMS-V concentrations. This method appears to work equally well for both linear and cyclic poly(dimethylsiloxane)s. Thus, the methodology described here has the potential to allow the measurement of less than 1 microgram of silicone/g of biological tissue. The overall goal of this research is to establish and validate a methodology by which the unequivocal identification and quantitation of poly(dimethylsiloxane)s can be accomplished.