Dibutyltin dichloride

H301: Toxic if swallowed [Danger Acute toxicity, oral]

H312: Harmful in contact with skin [Warning Acute toxicity, dermal]

H314: Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

H330: Fatal if inhaled [Danger Acute toxicity, inhalation]

H341: Suspected of causing genetic defects [Warning Germ cell mutagenicity]

H360FD: May damage fertility; May damage the unborn child [Danger Reproductive toxicity]

H372 **: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]

H400: Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410: Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

P203, P260, P264, P270, P271, P273, P280, P284, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P317, P318, P319, P320, P321, P330, P362+P364, P363, P391, P403+P233, P405, and P501 (click each P-code to see the statement)

H301 (99.2%): Toxic if swallowed [Danger Acute toxicity, oral]

H312 (100%): Harmful in contact with skin [Warning Acute toxicity, dermal]

H314 (100%): Causes severe skin burns and eye damage [Danger Skin corrosion/irritation]

H317 (41.4%): May cause an allergic skin reaction [Warning Sensitization, Skin]

H318 (49.6%): Causes serious eye damage [Danger Serious eye damage/eye irritation]

H330 (100%): Fatal if inhaled [Danger Acute toxicity, inhalation]

H341 (100%): Suspected of causing genetic defects [Warning Germ cell mutagenicity]

H360 (59%): May damage fertility or the unborn child [Danger Reproductive toxicity]

H360FD (41.4%): May damage fertility; May damage the unborn child [Danger Reproductive toxicity]

H370 (41.4%): Causes damage to organs [Danger Specific target organ toxicity, single exposure]

H372 (99.6%): Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]

H400 (100%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410 (100%): Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

P203, P260, P261, P264, P264+P265, P270, P271, P272, P273, P280, P284, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P308+P316, P316, P317, P318, P319, P320, P321, P330, P333+P317, P362+P364, P363, P391, P403+P233, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 256 reports by companies from 16 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website.

H318: Causes serious eye damage [Danger Serious eye damage/eye irritation]

H360: May damage fertility or the unborn child [Danger Reproductive toxicity]

H370: Causes damage to organs [Danger Specific target organ toxicity, single exposure]

H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]

P203, P260, P264, P264+P265, P270, P271, P273, P280, P284, P301+P316, P301+P330+P331, P302+P361+P354, P304+P340, P305+P354+P338, P308+P316, P316, P317, P318, P319, P320, P321, P330, P363, P391, P403+P233, P405, and P501 (click each P-code to see the statement)

H317: May cause an allergic skin reaction [Warning Sensitization, Skin]

P203, P260, P261, P264, P270, P271, P272, P273, P280, P284, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P317, P318, P319, P320, P321, P330, P333+P317, P362+P364, P363, P391, P403+P233, P405, and P501 (click each P-code to see the statement)

To fight fire, use water, foam, CO2, dry chemical.

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

If employees' clothing has had any possibility of being contaminated with ... dibutyltin dichloride, employees should change into uncontaminated clothing before leaving the work premises. ... Clothing contaminated with ... dibutyltin dichloride ... should be placed in closed containers for storage until it can be discarded or until provision is made for the removal of contaminant from the clothing. If the clothing is to be laundered or otherwise cleaned to remove the contaminant, the person performing the operation should be informed of contaminant's hazard properties. ... Non-impervious clothing which becomes contaminated with ... dibutyltin dichloride should be removed promptly & not reworn until the contaminant is removed ... .

Where exposure of an employee's body to dibutyltin dichloride or liquids containing dibutyltin dichloride may occur, facilities for quick drenching of the body should be provided within the immediate work area for emergency use. Skin that becomes contaminated with ... dibutyltin dichloride should be immediately flushed with large amounts of water to remove any contaminant. Workers subject to skin contact with solid ... dibutyltin dichloride should wash with soap or mild detergent & water any areas of the body that may have contacted any contaminant at the end of each work day. ... Eating & smoking should not be permitted in areas where ... dibutyltin dichloride ... /is/ handled, processed, or stored. Employees who handle ... dibutyltin dichloride ... should wash their hands thoroughly with soap or mild detergent & water before eating, smoking, or using toilet facilities.

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. All contaminated clothing should not be taken home at end of shift, but should remain at employee's place of work for cleaning.

Wherever possible, safer substitutes should be used in the place of alkyltin compounds. When it is necessary to make and use them ... /handling should be done in/ enclosed systems ... /equipped with/ exhaust ventilation. Engineering control should ensure that exposure limits are not exceeded. Personal protective equipment should be worn, & in appropriate circumstances respiratory protection should be used. Emergency showers should be installed ... to allow workers to wash immediately after splashes. /Organotin compounds/

For more Preventive Measures (Complete) data for DI-N-BUTYLTIN DICHLORIDE (13 total), please visit the HSDB record page.

0.1 [mg/m3], inhalable fraction, as Sn[German Research Foundation (DFG)]

0.1 [mg/m3], as Sn

25.0 [mg/m3], as Sn

0.2 [mg/m3], as Sn

8 hr Time Weighted Avg (TWA): 0.1 mg/cu m; 15 min Short Term Exposure Limit (STEL): 0.2 mg/cu m, skin. /Tin, organic cmpd, as Sn/

A4; Not classifiable as a human carcinogen. /Tin, organic cmpd, as Sn/

Personnel protection: ... Wear appropriate chemical protective gloves, boots and goggles. ... /Organotin compounds, NOS/

Skin contact should be prevented by protective clothing. /Tin & inorganic tin cmpd/

Recommendations for respirator selection: Max. concn for use: 1 mg/cu m). Any chemical cartridge respirator with organic vapor cartridge(s) in combination with a dust and mist filter. Any supplied-air respirator. /Tin (organic cmpds, as Sn)/

Recommendations for respirator selection: Max. concn for use: 2.5 mg/cu m). Any supplied-air respirator operated in a continuous-flow mode. Any powered, air-purifying respirator with organic vapor cartridge(s) in combination with a dust and mist filter. /Tin (organic cmpds, as Sn)/

For more Personal Protective Equipment (PPE) (Complete) data for DI-N-BUTYLTIN DICHLORIDE (8 total), please visit the HSDB record page.

Other Solid; Liquid

White solid; mp = 43 deg C; [Hawley] White paste with an acrid odor; mp = 39-41 deg C; [MSDSonline]

White crystalline solid

Light tan or colorless solid or semisolid

135 °C @ 10 mm Hg

335 °F (open cup)

SOL IN ETHER, BENZENE, ALCOHOL

Insoluble in cold water; hydrolyzed in hot water.

1.36 @ 24 °C/D

10.5 (Air = 1)

2 mm Hg at 100 °C

log Kow=0.97

DECOMP BY HOT & COLD WATER, DECOMP AT 113.6 °C, 60 MM HG

... Emits highly toxic fumes of hydrochloric acid.

Index of refraction: 1.4991 @ 51 °C

Metals -> Tin Compounds, Organic

FCS -> FDA Inventory of Food Contact Substances Listed in 21 CFR

... Will react with water or steam to produce heat and toxic fumes; can react vigorously with oxidizing materials.

Organotin compounds produce neurotoxic and immunotoxic effects. Organotins may directly activate glial cells contributing to neuronal cell degeneration by local release of pro-inflammatory cytokines, tumor necrosis factor-_, and/or interleukins. They may also induce apoptosis by direct action on neuronal cells. Organotin compounds stimulate the neuronal release of and/or decrease of neuronal cell uptake of neurotransmitters in brain tissue, including aspartate, GABA, glutamate, norepinephrine, and serotonin. This may be either a contributing factor to or result of the neuronal cell loss. The immunotoxic effects of organotins are characterized by thymic atrophy caused by the suppression of proliferation of immature thymocytes and apoptosis of mature thymocytes. Organotin compounds are believed to exert these effects by suppressing DNA and protein synthesis, inducing the expression of genes involved in apoptosis (such as nur77), and disrupting the regulation of intracellular calcium levels, giving rise to the uncontrolled production of reactive oxygen species, release of cytochrome c to the cytosol, and the proteolytic and nucleolytic cascade of apoptosis. The suppression of proliferation of immature thymocytes further results in the suppression of T-cell-mediated immune responses. Organotins are also endocrine disruptors and are believed to contribute to obesity by inappropriate receptor activation, leading to adipocyte differentiation. Inorganic tin triggers eryptosis, contributing to tin-induced anemia. (L308, A182, A184)

A4; Not classifiable as a human carcinogen. /Tin, organic cmpd, as Sn/

No indication of carcinogenicity to humans (not listed by IARC).

Breathing or swallowing, or skin contact with organotins, can interfere with the way the brain and nervous system work, causing death in severe cases. Organic tin compounds may also damage the immune and reproductive system. (L307, L308)

Oral (L308) ; inhalation (L308) ; dermal (L308)

Inorganic or organic tin compounds placed on the skin or in the eyes can produce skin and eye irritation. (L308)

Neurotoxin - Other CNS neurotoxin

Occupational hepatotoxin - Secondary hepatotoxins: the potential for toxic effect in the occupational setting is based on cases of poisoning by human ingestion or animal experimentation.

Dermatotoxin - Skin burns.

ACGIH Carcinogen - Not Classifiable.

ATSDR Final

LC50 (rat) >364 mg/m3/4h

LD50: 70 mg/kg (Oral, Mouse) (T14)

LD50: 180 mg/kg (Intravenous, Mouse) (T14)

LD50: 7.5 mg/kg (Intraperitoneal, Rat) (T21)

LD50 RAT INHALATION 73 MG/L/HR

LD50 White mouse oral 35 mg/kg

LD50 Rat male oral 100 mg/kg (oil solution)

LD50 Rat male intraperitoneal 7.5 mg/kg

For more Non-Human Toxicity Values (Complete) data for DI-N-BUTYLTIN DICHLORIDE (7 total), please visit the HSDB record page.

The effects of timing of a single intragastric application of dibutyltin dichloride, at a dosage of 30 mg/kg body wt, on N-nitrosobis(2-oxopropyl) amine induced pancreatic carcinomas have been studied in female Syrian golden hamsters. Dibutyltin dichloride, which has been shown to produce selected bile duct injury, was admin either 1 wk before or 1 wk after a single injection of N-nitrosobis(2-oxopropyl) amine (20 mg/kg body wt). The incidence of ductal adenocarcinomas strikingly decr in hamsters when dibutyltin dichloride was ingested after N-nitrosobis(2-oxopropyl) amine treatment, but remained unaffected when dibutyltin dichloride was given before carcinogen treatment. Two cases of sarcoma were observed in the group treated with dibutyltin dichloride before N-nitrosobis(2-oxopropyl) amine injection. The incidence of insulomas, which were considered as spontaneous tumors, was not influenced by dibutyltin dichloride. These results showed that intragastric application of dibutyltin dichloride after N-nitrosobis(2-oxopropyl) amine treatment significantly reduced the induction of pancreatic cancer.

The interaction of dibutyltin chloride and tributyltin chloride with human erythrocyte membrane proteins was assessed. Erythrocyte membrane was prepared from fresh Rh positive human blood, and known concentrations of membrane protein were incubated with 0 to 500 um dibutyltin or tributyltin at 37 °C for 15 min. The bound and free tin complexes were estimated using the dithiozone method, and the alkyltin complexes were analyzed by sodium dodecyl sulfate polycrylamide gel electrophoresis. Scatchard analysis of the binding data for dibutyltin fitted the results to two binding sites with affinities of 25,300 and 2060 per mole. Scatchard analysis of the binding of tributyltin to erythrocyte membrane indicated a single class of binding sites with an affinity of 6780 per mole. Polyacrylamide gel electrophoresis indicated tributyltin binding to be associated with a single band of proteins in the molecular weight region of 90,000 to 100,000. Dibutyltin binding was associated with this band and with lower molecular weight proteins. /It was/ concluded that the different binding patterns of dibutyltin and tributyltin with erythrocyte membrane protein represent different mechanisms for the biological effects of the tin compounds.

The in vivo effects of di-n-butyltin dichloride on the enzyme activity and lipid constituents of liver plasma membrane were studied in male albino rats. The rats were ip administered with 0.1 ml (10% v/v) ethanol either alone or containing di-n-butyltin dichloride (10 or 30 mg/kg/day) for 7 consecutive days. A significant inhibition of plasma membrane marker enzymes such as 5'-nucleotidase, gamma-glutamyltranspeptidase, alkaline phosphatase, magnesium(+2)-ATPase, sodium(+)/potasium(+)-ATPase and calcium(+2)-ATPase occurred in di-n-dibutyltin dichloride treated rats when compared with respective controls. Other important bioconstituents such as sialic acid and total phospholipid/cholesterol ratio were also significantly decreased in di-n-butyltin dichloride treated rats when compared with corresponding controls. These results suggest that interaction of di-n-dibutyltin dichloride with liver plasma membrane constituents might cause derangement of its structural and functional organization, thus leading to hepatotoxicity.

IN WORKERS HANDLING ... /DIBUTYLTIN CHLORIDE/, SKIN LESIONS, EVEN BURNS, HAVE BEEN FOUND. THE IRRITANT EFFECT APPEARED BETWEEN 1 & 8 HR AFTER CONTACT. HEALING WAS RAPID AFTER REMOVAL FROM EXPOSURE. THE EYES CAN ALSO BE AFFECTED ... BUT THE DAMAGE WAS NOT CHRONIC.

BLAST TRANSFORMATION OF HUMAN THYMOCYTES WAS INHIBITED AT CONCENTRATIONS AS LOW AS 0.02 UG/ML MEDIUM.

One instance of eye injury is reported in a worker who accidentally splashed the liquid in his face and eyes. Despite immediate washing with water, lacrimation and conjunctival hyperemia appeared within minutes and persisted for four days. At the end of a week the skin was still erythematous, but the eyes appeared normal.

DIBUTYLTIN CHLORIDE BY INHALATION FOR 1 HR OF RATS AT 1470 MG/CU M, ALTHOUGH PRODUCING HYPOACTIVITY, PTOSIS, & SALIVATION DURING 14 DAYS FOLLOWING, CAUSED NO DEATHS.

... INDICATIONS OF NONACCUMULATION WERE SEEN IN LONG-TERM (3 MO) ADMINISTRATION OF DIBUTYLTIN CHLORIDE TO RATS AT LEVELS OF 25, 50, & 100 PPM; NO LESIONS RESULTED FROM THIS REGIMEN OTHER THAN THOSE SEEN FROM SINGLE DOSES /HYPOACTIVITY, PTOSIS, SALIVATION/.

... STUDYING ... ACTION OF SEVERAL DISUBSTITUTED ORGANO TIN CMPD ON THYMUS & THYMUS DEPENDENT LYMPHOID TISSUE, FOUND ... DIBUTYL TIN DICHLORIDE (DBTC) MOST TOXIC OF ORGANOTIN CMPD TESTED, CAUSING MORTALITY IN 6 OF 20 WEANLING RATS AT DIETARY LEVEL OF 150 PPM & SEVERE LIVER & BILIARY CHANGES, AS WELL AS ABDOMINAL EDEMA ... .

... DIBUTYL TIN CHLORIDE, A DOSE OF 5 MG/KG BODY WEIGHT DISSOLVED IN TWEEN 80 CAUSED AN ATTACK ON BILE DUCTS WITHIN 1 HR OF /INTRAVENOUS/ INJECTION /TO RATS/.

For more Non-Human Toxicity Excerpts (Complete) data for DI-N-BUTYLTIN DICHLORIDE (28 total), please visit the HSDB record page.

Dibutyltin dichloride's production and use as an intermediate in the synthesis of other dibutyltin compounds may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 0.079 mm Hg at 25 °C indicates dibutyltin chloride will exist solely as a vapor in the ambient atmosphere. Vapor-phase dibutyltin chloride will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 14 hours. Dibutyltin dichloride is expected to dissociate forming the cation, dibutyltin, in the environment which will exist as or will be rapidly converted to dibutyltin oxides, hydroxides, carbonates, or hydrated cations. If released to soil, dibutyltin species are expected to adsorb to organic carbon and clay. Volatilization from moist soil surfaces is not expected to be an important fate process because the cation is not expected to volatilize. Dibutyltin dichloride may also biodegrade in soil and water since tributyltins are converted to dibutyltin and monobutyltin. If released into water, dibutyltin is expected to adsorb to suspended solids and sediment. Volatilization from water surfaces is not expected to be an important fate process because the cation is not expected to volatilize. A BCF of 12 suggests bioconcentration in aquatic organisms is low. Occupational exposure to dibutyltin dichloride may occur through dermal contact with this compound at workplaces where dibutyltin dichloride is produced or used. Monitoring data indicate that the general population may be exposed to dibutyltin dichloride (as dibutyltin) via ingestion of fish from surface waters contaminated with dibutyltin. (SRC)

Dibutyltin dichloride's production and use as an intermediate in the synthesis of other dibutyltin compounds(1) may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Dibutyltin dichloride is expected to dissociate in soil forming the cation, dibutyl tin, which will exist as or will be rapidly converted to dibutyltin oxides, hydroxides, carbonates, or hydrated cations(1). Dibutyltin species are expected to adsorb to organic carbon and clay(SRC). Volatilization from moist soil surfaces is not expected to be an important fate process because the cation is not expected to volatilize(SRC). Dibutyltin dichloride may also biodegrade in soil, since tributyltins are converted to dibutyltin and monobutyltin(2).

AQUATIC FATE: Dibutyltin dichloride is expected to dissociate in water forming the cation, dibutyltin(SRC). Cations generally adsorb to suspended solids and sediment more strongly than their neutral counterparts(SRC). Volatilization from water surfaces is not expected to be an important fate process because the cation is not expected to volatilize(SRC). According to a classification scheme(2), a BCF value of 12 for round crucian carp(3) suggests the potential for bioconcentration in aquatic organisms is low(SRC). Dibutyltin dichloride may also biodegrade in water, since tributyltins are converted to dibutyltin and monobutyltin(1). Tributyltin species in water were sequentially degraded to dibutyltin, monobutyltin, and finally to tin ions in water/sediment mixtures or water alone from Toronto Harbor, Canada(1). Small quantities of dimethyldibutyltin were occasionally detected in these experiments in water/sediment and water alone, but not in the sterile controls, which indicates the possibility of biomethylation of dibutyltin compounds(1).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), dibutyltin dichloride, which has an estimated vapor pressure of 0.079 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase dibutyltin dichloride 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 14 hours(SRC), calculated from its rate constant of 28X10-12 cu cm/molecule-sec at 25 °C(SRC) determined using a structure estimation method(3).

Tributyltin species, obtained by dissolution of tributyltin oxide in water, are sequentially degraded by microorganisms to dibutyltin, monobutyltin (similar to the monobutyltin obtained by dissolution of mono-n-butyltin trichloride), and finally to inorganic tin using water/sediment mixtures or water alone from Tornoto Harbor, Canada(1). Butyltin compounds may be susceptible to biomethylation based upon the possible biomethylation of dibutyltin and tributyltin compounds(1).

... BU-1-(14)C-LABELED DIBUTYLTIN DICHLORIDE WAS LINEARLY DEGRADED BY UV IRRADIATION.

Dibutyltin dichloride was converted into monobutyltin derivatives under certain sterile conditions.

The rate constant for the vapor-phase reaction of dibutyltin dichloride with photochemically-produced hydroxyl radicals has been estimated as 28X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 14 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Dibutyltin dichloride is expected to dissociate in water forming the cation, dibutyltin(SRC). Dibutyltin compounds in environmental waters probably either exist as, or will rapidly be converted to oxides, hydroxides, carbonates, or hydrated cations(2). Dibutyltin cation may react with water and behave like a simple protic acid due to the resulting formation of hydronium ion and either dibutyltin dihydroxide or other dibutyltin-hydroxide species at concn above approx 1X10-5 M, based upon the behavior of dimethyltin dication(3). In seawater, the chloride ion may compete effectively with hydroxide ions resulting in the presence of dibutyltin dichloride in the mixture of dibutyltin species(4). Dissociation and speciation of dibutyltin dichloride in the environment may affect its fate and transport processes(SRC). Dibutyltin compounds may react with sulfides present in sediment, leading to the formation of dibutyltin sulfide(2). The dibutyltin species obtained by dissolution of dibutyltin dichloride in water weakly absorb light at wavelengths >290 nm(5) and, therefore, dibutyltin compounds may be subject to direct photolysis in sunlit waters(SRC).

The observed BCF for dibutyltin dichloride in round crucian carp (Carassius carassius grandoculis) muscle, vertebra, liver, and kidney tissue were 12, 46, 135, and 61, respectively(2). In a tin bioconcentration study, the freshwater clam, Anodonta anatina, was exposed to dibutyltin dichloride for 7 months at a total concn of 15 ug tin equivalents/liter(2). Only total tin concn were determined(2). The average concn of tin in the gills, mantle plus mantle-edge, midgut gland, kidney, and remaining tissue fraction were as follows: 0.94, 0.13, 0.22, 0.60, 23.5, and 0.56 ug Sn/g wet wt, respectively(2). The max BCF for dibutyltin dichloride for the tissues are as follows (if all of the tin in the clams was in this form): 63, 8.6, 15, 40, 1,567, and 37, respectively(2). According to a classification scheme(2), a BCF value of 12 suggests bioconcentration in aquatic organisms is low(SRC).

Dibutyltin dichloride is expected to dissociate in water forming the cation, dibutyltin(SRC). Cations generally adsorb to organic carbon and clay(SRC). The adsorption of dibutyltin dichloride was studied under simulated estuarine conditions which included artificial seawater (salinity(S)), hydrous iron oxide (moderately particulate matter (PM)), and fulvic acid(1). The partition coefficients Kp (ug/kg)/ug/l) ranged from zero (no adsortion at pH 8.2 and with low S and high PM concn or high S and low PM concn) to 110,000 (at pH 6.2 and high S and low PM concn)(1). Based upon these results, dibutyltin dichloride is expected to exist mainly in the solution (aqueous) phase in estuarine waters and seawater(1). In a study of desorption from sediment, approximately 1% of the initial dibutyltin species was observed to desorb from the unshaken Toronto Harbor sediment/water mixtures in 10.6 months(2).

Dibutyltin dichloride's production and use as an intermediate in the synthesis of other dibutyltin compounds may result in its release to the environment through various waste streams. If released to air, an estimated vapor pressure of 0.079 mm Hg at 25 °C indicates dibutyltin chloride will exist solely as a vapor in the ambient atmosphere. Vapor-phase dibutyltin chloride will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 14 hours. Dibutyltin dichloride is expected to dissociate forming the cation, dibutyltin, in the environment which will exist as or will be rapidly converted to dibutyltin oxides, hydroxides, carbonates, or hydrated cations. If released to soil, dibutyltin species are expected to adsorb to organic carbon and clay. Volatilization from moist soil surfaces is not expected to be an important fate process because the cation is not expected to volatilize. Dibutyltin dichloride may also biodegrade in soil and water since tributyltins are converted to dibutyltin and monobutyltin. If released into water, dibutyltin is expected to adsorb to suspended solids and sediment. Volatilization from water surfaces is not expected to be an important fate process because the cation is not expected to volatilize. A BCF of 12 suggests bioconcentration in aquatic organisms is low. Occupational exposure to dibutyltin dichloride may occur through dermal contact with this compound at workplaces where dibutyltin dichloride is produced or used. Monitoring data indicate that the general population may be exposed to dibutyltin dichloride (as dibutyltin) via ingestion of fish from surface waters contaminated with dibutyltin. (SRC)

Dibutyltin dichloride's production and use as an intermediate in the synthesis of other dibutyltin compounds(1) may result in its release to the environment through various waste streams(SRC).

TERRESTRIAL FATE: Dibutyltin dichloride is expected to dissociate in soil forming the cation, dibutyl tin, which will exist as or will be rapidly converted to dibutyltin oxides, hydroxides, carbonates, or hydrated cations(1). Dibutyltin species are expected to adsorb to organic carbon and clay(SRC). Volatilization from moist soil surfaces is not expected to be an important fate process because the cation is not expected to volatilize(SRC). Dibutyltin dichloride may also biodegrade in soil, since tributyltins are converted to dibutyltin and monobutyltin(2).

AQUATIC FATE: Dibutyltin dichloride is expected to dissociate in water forming the cation, dibutyltin(SRC). Cations generally adsorb to suspended solids and sediment more strongly than their neutral counterparts(SRC). Volatilization from water surfaces is not expected to be an important fate process because the cation is not expected to volatilize(SRC). According to a classification scheme(2), a BCF value of 12 for round crucian carp(3) suggests the potential for bioconcentration in aquatic organisms is low(SRC). Dibutyltin dichloride may also biodegrade in water, since tributyltins are converted to dibutyltin and monobutyltin(1). Tributyltin species in water were sequentially degraded to dibutyltin, monobutyltin, and finally to tin ions in water/sediment mixtures or water alone from Toronto Harbor, Canada(1). Small quantities of dimethyldibutyltin were occasionally detected in these experiments in water/sediment and water alone, but not in the sterile controls, which indicates the possibility of biomethylation of dibutyltin compounds(1).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), dibutyltin dichloride, which has an estimated vapor pressure of 0.079 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase dibutyltin dichloride 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 14 hours(SRC), calculated from its rate constant of 28X10-12 cu cm/molecule-sec at 25 °C(SRC) determined using a structure estimation method(3).

Tributyltin species, obtained by dissolution of tributyltin oxide in water, are sequentially degraded by microorganisms to dibutyltin, monobutyltin (similar to the monobutyltin obtained by dissolution of mono-n-butyltin trichloride), and finally to inorganic tin using water/sediment mixtures or water alone from Tornoto Harbor, Canada(1). Butyltin compounds may be susceptible to biomethylation based upon the possible biomethylation of dibutyltin and tributyltin compounds(1).

... BU-1-(14)C-LABELED DIBUTYLTIN DICHLORIDE WAS LINEARLY DEGRADED BY UV IRRADIATION.

Dibutyltin dichloride was converted into monobutyltin derivatives under certain sterile conditions.

The rate constant for the vapor-phase reaction of dibutyltin dichloride with photochemically-produced hydroxyl radicals has been estimated as 28X10-12 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 14 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Dibutyltin dichloride is expected to dissociate in water forming the cation, dibutyltin(SRC). Dibutyltin compounds in environmental waters probably either exist as, or will rapidly be converted to oxides, hydroxides, carbonates, or hydrated cations(2). Dibutyltin cation may react with water and behave like a simple protic acid due to the resulting formation of hydronium ion and either dibutyltin dihydroxide or other dibutyltin-hydroxide species at concn above approx 1X10-5 M, based upon the behavior of dimethyltin dication(3). In seawater, the chloride ion may compete effectively with hydroxide ions resulting in the presence of dibutyltin dichloride in the mixture of dibutyltin species(4). Dissociation and speciation of dibutyltin dichloride in the environment may affect its fate and transport processes(SRC). Dibutyltin compounds may react with sulfides present in sediment, leading to the formation of dibutyltin sulfide(2). The dibutyltin species obtained by dissolution of dibutyltin dichloride in water weakly absorb light at wavelengths >290 nm(5) and, therefore, dibutyltin compounds may be subject to direct photolysis in sunlit waters(SRC).

The observed BCF for dibutyltin dichloride in round crucian carp (Carassius carassius grandoculis) muscle, vertebra, liver, and kidney tissue were 12, 46, 135, and 61, respectively(2). In a tin bioconcentration study, the freshwater clam, Anodonta anatina, was exposed to dibutyltin dichloride for 7 months at a total concn of 15 ug tin equivalents/liter(2). Only total tin concn were determined(2). The average concn of tin in the gills, mantle plus mantle-edge, midgut gland, kidney, and remaining tissue fraction were as follows: 0.94, 0.13, 0.22, 0.60, 23.5, and 0.56 ug Sn/g wet wt, respectively(2). The max BCF for dibutyltin dichloride for the tissues are as follows (if all of the tin in the clams was in this form): 63, 8.6, 15, 40, 1,567, and 37, respectively(2). According to a classification scheme(2), a BCF value of 12 suggests bioconcentration in aquatic organisms is low(SRC).

Dibutyltin dichloride is expected to dissociate in water forming the cation, dibutyltin(SRC). Cations generally adsorb to organic carbon and clay(SRC). The adsorption of dibutyltin dichloride was studied under simulated estuarine conditions which included artificial seawater (salinity(S)), hydrous iron oxide (moderately particulate matter (PM)), and fulvic acid(1). The partition coefficients Kp (ug/kg)/ug/l) ranged from zero (no adsortion at pH 8.2 and with low S and high PM concn or high S and low PM concn) to 110,000 (at pH 6.2 and high S and low PM concn)(1). Based upon these results, dibutyltin dichloride is expected to exist mainly in the solution (aqueous) phase in estuarine waters and seawater(1). In a study of desorption from sediment, approximately 1% of the initial dibutyltin species was observed to desorb from the unshaken Toronto Harbor sediment/water mixtures in 10.6 months(2).

Dibutyltin dichloride is expected to dissociate in water forming the cation, dibutyltin(SRC). Volatilization from moist soil and water surfaces is not expected to be an important fate process because the cation is not expected to volatilize(SRC). Dibutyltin dichloride is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 0.079 mm Hg(SRC), determined from a fragment constant method(1).

SURFACE WATER: The only monitoring data located were for dibutyltin (Bu2Sn++) without regard for the identity of the accompanying anion(s) and concn is often reported in tin equivalents(1). Dibutyltin was detected and quantified in 27 of 214 samples of unfiltered subsurface water from 209 locations in Canada sampled between 1982- 1985 at concentrations ranging from 0.01 to 1.36 ppb tin (average concn of pos, quantified samples = 0.12 ppb tin); dibutyltin also was detected, not quantified in another 21 of the samples (concn range from approx 3.3 parts/trillion tin (limit of detection) to <0.01 ppb tin (limit of quantitation))(1). Dibutyltin was detected at one of six sites in New York state at 0.01 ppb tin, but was not detected in one sample from the Detroit River, MI(1).

SURFACE WATER: The only monitoring data located were for dibutyltin (Bu2Sn++) without regard for the identity of the accompanying anion(s)(1). Dibutyltin was detected and quantified in 8 of 30 samples of unfiltered subsurface water from Ontario, Canada, lakes and rivers at concn ranging from 0.01 (detection limit) to 7.30 ppb (Bu2Sn++) (avg concn of pos samples, 0.099 ppb)(1). Dibutyltin was detected in surface microlayer water samples (top 60 um of water column) from mainly the same locations in 12 of 28 samples at concn ranging from 0.71 to 2600 ppb (Bu2Sn++) (avg concn of pos samples, 763 ppb); dibutyltin and tributyltin were concn by a factor of up to 1X10+4 in the surface microlayer relative to subsurface water(1).

SURFACE WATER: The only monitoring data located were for dibutyltin (Bu2Sn++) without regard for the identity of the accompanying anion(s) and concn is often reported in tin equivalents(1). Dibutyltin was detected and quantified in samples of unfiltered subsurface water from 5 of 6 sites in Toronto Harbor, Ontario at concn ranging from 0.01 to 0.10 ppb tin (avg concn was 0.04 ppb tin), and it was detected, not quantified, in the other site in the harbor; dibutyltin was detected, not quantified, in water from 1 of 2 sites outside the harbor(1).

SURFACE WATER: The only monitoring data located were for dibutyltin (Bu2Sn++) without regard for the identity of the accompanying anion(s)(1). Analysis for dibutyltin in samples of unfiltered surface microlayer and subsurface water from Maryland waters of Chesapeake Bay sampled approx monthly between July 1985 to June 1986, gave the following results: four marinas, microlayer, 32 of 44 samples pos, 0.033 to 1.156 ppb, 0.25 ppb avg; subsurface 36 of 48 samples pos, 0.010 to 0.298 ppb, 0.080 ppb avg; Baltimore Harbor, microlayer, 3 of 6 samples pos, 0.017 to 0.035 ppb, 0.026 ppb avg; subsurface, 5 of 12 pos, 0.016 to 0.035 ppb, 0.026 ppb avg; Chesapeake and Delaware Canal (a major shipping canal), microlayer, 3 of 6 samples pos, 0.022 to 1.1 ppb, 0.40 ppb avg; subsurface, 3 of 12 pos, 0.012 to 0.016 ppb; Potomac and Choptank Rivers, microlayer, 1 of 11 pos, 0.029 ppb; subsurface, 3 of 24 pos, 0.020 to 0.022 ppb(1).

SURFACE WATER: The only monitoring data located were for dibutyltin (Bu2Sn++) without regard for the identity of the accompanying anion(s)(1). Dibutyltin was detected in unfiltered surface and bottom water from San Diego Harbor in 28 of 32 samples taken in 1983 through 1985 from 5 stations at concn ranging from 0.01 to 0.46 ppb (0.12 avg concn)(1).

SEDIMENT: The only monitoring data located were for dibutyltin (Bu2Sn++) without regard for the identity of the accompanying anion(s) and concn was reported in tin equivalents(1). Dibutyltin was detected and quantified in 61 of 235 samples of the top 2 cm of sediment from bodies of surface water in Canada sampled between 1982-1985 at concentrations ranging from 0.01 to 8.51 ppm tin (dry wt) (average concn of pos, quantified samples = 0.49 ppm tin (dry wt); dibutyltin also was detected, not quantified in another 27 of the samples (concn range from approx >3.3 ppb tin (dry wt) (limit of detection) to <0.01 ppm tin (dry wt) (limit of quantitation))(1). Dibutyltin was not detected in sediment from one site in Michigan and six sites in New York state(1).

SEDIMENT: The only monitoring data located were for dibutyltin (Bu2Sn++) without regard for the identity of the accompanying anion(s) and concn is often reported in tin equivalents(1). Dibutyltin was detected and quantified in samples of sediment from 5 of 6 sites in Toronto Harbor, Ontario at concn ranging from 0.01 to 0.26 ppm tin (wet wt) (avg concn was 0.09 ppm tin (wet wt)); dibutyltin was not detected in sediment from the other site within and 2 sites outside the harbor(1).

The only monitoring data located were for dibutyltin (Bu2Sn++) without regard for the identity of the accompanying anion(s) and concn was reported in Sn equivalents(1). Dibutyltin was detected and quantified in 1 of 14 samples of whole fish collected from Canadian surface waters during 1982 and 1984 at the following concn (specie; location): 0.05 ppm Sn (wet wt), herring (C. harengus pallasi; Vancouver Harbor); dibutyltin also was detected, not quantified in another 4 of the samples (concn <0.01 ppm Sn (wet wt) (limit of quantitation))(1).

Occupational exposure to dibutyltin dichloride may occur through dermal contact with this compound at workplaces where dibutyltin dichloride is produced or used. Monitoring data indicate that the general population may be exposed to dibutyltin dichloride (as dibutyltin) via ingestion of fish from surface waters contaminated with dibutyltin. (SRC)

SRP: At the time of review, criteria for land treatment or burial (sanitary landfill) disposal practices are subject to significant revision. Prior to implementing land disposal of waste residue (including waste sludge), consult with environmental regulatory agencies for guidance on acceptable disposal practices.

UN 3146; Organotin cmpd, solid, not otherwise specified

UN 2788; Organotin cmpd, liquid, not otherwise specified

IMO 6.1; Organotin cmpd, liquid or solid, not otherwise specified