Tetrabutyltin

H301 (86.3%): Toxic if swallowed [Danger Acute toxicity, oral]

H302 (11.8%): Harmful if swallowed [Warning Acute toxicity, oral]

H312 (86.3%): Harmful in contact with skin [Warning Acute toxicity, dermal]

H315 (92.2%): Causes skin irritation [Warning Skin corrosion/irritation]

H319 (88.2%): Causes serious eye irritation [Warning Serious eye damage/eye irritation]

H372 (90.2%): Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]

H400 (90.2%): Very toxic to aquatic life [Warning Hazardous to the aquatic environment, acute hazard]

H410 (92.2%): Very toxic to aquatic life with long lasting effects [Warning Hazardous to the aquatic environment, long-term hazard]

P260, P264, P264+P265, P270, P273, P280, P301+P316, P301+P317, P302+P352, P305+P351+P338, P317, P319, P321, P330, P332+P317, P337+P317, P362+P364, P391, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 51 reports by companies from 9 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.

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

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]

P261, P272, P273, P280, P302+P352, P321, P333+P317, P362+P364, P391, and P501 (click each P-code to see the statement)

H320: Causes eye irritation [Warning Serious eye damage/eye irritation]

H336: May cause drowsiness or dizziness [Warning Specific target organ toxicity, single exposure; Narcotic effects]

H361: Suspected of damaging fertility or the unborn child [Warning Reproductive toxicity]

H373: May causes damage to organs through prolonged or repeated exposure [Warning Specific target organ toxicity, repeated exposure]

P203, P260, P261, P264+P265, P271, P273, P280, P304+P340, P305+P351+P338, P318, P319, P337+P317, P391, P403+P233, P405, and P501 (click each P-code to see the statement)

H315: Causes skin irritation [Warning Skin corrosion/irritation]

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

H361d: Suspected of damaging the unborn child [Warning Reproductive toxicity]

P203, P261, P264, P264+P265, P272, P280, P302+P352, P305+P354+P338, P317, P318, P321, P332+P317, P333+P317, P362+P364, P405, and P501 (click each P-code to see the statement)

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.

Clothing contaminated with ... tetrabutyltin ... 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 ... tetrabutyltin ... should be removed promptly & not reworn until the contaminant is removed. ...

Skin that becomes contaminated with ... tetrabutyltin ... should be promptly washed or showered with soap or mild detergent & water to remove any contaminant. ... Eating & smoking should not be permitted in areas where ... tetrabutyltin ... is handled, processed, or stored.

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.

0.02 [mg/m3], inhalable fraction[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/

Employees should be provided with & required to use impervious clothing, gloves, face shields (8 inch minimum), & other appropriate protective clothing necessary to prevent repeated or prolonged skin contact with ... solid or liquid tetrabutyltin. ... Employees should be provided with & required to use dust- & splash-proof safety goggles where ... liquid tetrabutyltin ... may contact the eyes.

Colorless or slightly yellow liquid; [Hawley] Colorless liquid; [MSDSonline]

Colorless or slightly yellow oily liquid

Distinct, characteristic odor

145 °C @ 10 mm Hg

Insol in water; sol in most organic solvents

1.054 g/cu cm at 20 °C

0.0048 [mmHg]

0.0048 mm Hg at 20 °C

When heated to decomposition it emits acrid smoke and fumes.

DECOMPOSES AT 265 °C

61.3 kJ/mol

Index of refraction: 1.4727 @ 20 °C

The most important reactions which tetraorganic tins undergo are heterolytic, i.e. electrophilic and nucleophilic, cleavage and the Kocheshkov redistribution. The tin-carbon bond in tetraorganic tins is easily cleaved by halogens, hydrogen halides, and mineral acids. /Tetraorganotins/

Metals -> Tin Compounds, Organic

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.

ACGIH Carcinogen - Not Classifiable.

LC50 (mice) = 142 mg/m3

LD50: 6000 mg/kg (Oral, Mouse) (L345)

LD50: 56 mg/kg (Intravenous, Mouse) (L345)

LD50 Mouse intravenous 56 mg/kg

LD50 SWISS WEBSTER ALBINO MOUSE ORAL 6000 MG/KG

Irritant dose Rabbit ocular 500 mg/24 hr; irritant effects: mild eye irritation

Mild eye irritation /in rabbits/.

Studies were conducted using tetrabutyl tin and its iodine derivatives to determine the toxicity of these compounds to the gastrointestinal tract of male, mature white rabbits. The iodine derivatives tested included tributyl tin monoiodide and dibutyltin diiodide. The toxicity of these test compounds ranged from tributyl tin monoiodide being the most toxic and tetrabutyl tin the least, with dibutyltin diiodide being intermediate in toxicity, requiring 0.1, 0.15, and 5 cu cm, respectively, of each compound per kg body weight to be fatal. In producing anemia, the order of decreasing potency was dibutyltin diiodide, tributyl tin monoiodide, and tetrabutyl tin. The substitution of the butyl radical by iodine increased the toxicity of the tetrabutyl tin parent compound. After administration of the compounds was stopped, the anemic condition of the animals improved usually within 2 to 3 weeks, with only the worst cases taking 8 or 10 weeks to return to normal. Alsilin administered directly after the intake of these substances prevented their effects. /It was/ urged that these substances be handled with special care.

Five individual bioassay repellency or toxicity variables were estimated or determined for deer mice (Peromyscus maniculatus) and house mice (Mus musculus) under laboratory conditions. Approximate lethal doses or LD50 of 230 chemicals to deer mice were presented, as were food reduction values (3 day feeding test as a 2.0% treatment rate) for white seeds (Triticum aestivum) for 696 chemicals and Douglas fir seeds (Pseudotsuga menziesii) for 81 chemicals. A similar repellency evaluation using a 5 day test with white wheat seeds at a 2.0% treatment rate was conducted with house mice and the results for 347 chemicals were presented. These toxicity and repellency data should be useful to those disiring to predict the potential for acute toxicity in wild mammals following exposure to a wide variety of chemicals. A calculation of the daily chemical dose ingested in mg/kg/day during the wheat test on deer mice and its resultant effects on mortality were also presented for most of the 696 chemicals. This calculated value, when used along with the approximate lethal doses or LD50, should permit a rough estimate of the potential subacute toxicity of any tested chemical on wild mammals for which both types of data were available.

LC50 Pimephales promelas (fathead minnow) 45.2 ug/l/96 hr (confidence limit 41.6 - 49.2 mg/l), flow-through bioassay with measured concentrations, 25.3 °C, dissolved oxygen 6.8 mg/l, hardness 44.3 mg/l calcium carbonate, alkalinity 44.1 mg/l calcium carbonate, and pH 7.7.

EC50 Pimephales promelas (fathead minnow) 45.2 ug/l/96 hr (confidence limit 41.6 - 49.2 mg/l), flow-through bioassay with measured concentrations, 25.3 °C, dissolved oxygen 6.8 mg/l, hardness 44.3 mg/l calcium carbonate, alkalinity 44.1 mg/l calcium carbonate, and pH 7.7. Effect: loss of equilibrium.

Tetra-n-butyl tin's production and use as a rust inhibitor and chemical intermediate may result in its release to the environment through various waste streams. If released to air, a vapor pressure of 0.0048 mm Hg at 25 °C indicates tetra-n-butyl tin will exist solely as a vapor in the ambient atmosphere. Vapor-phase tetra-n-butyl tin 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 7 hrs. It may be susceptible to direct photolysis based upon the absorption of UV light >290 nm by tri-, di-, and monobutyltin compounds. If released to soil, tetra-n-butyl tin is expected to be immobile based upon an estimated Koc of 101,400. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 6 atm-cu m/mole. However, adsorption to soil is expected to attenuate volatilization. If released into water, tetra-n-butyl tin is expected to adsorb to suspended solids and sediment based upon the estimated Koc. Tetrabutyltin may be susceptible to biodegradation in water based upon possible biodegradability of other butyltin compounds such as tri-, di- and monobutyltin species. Volatilization from water surfaces is expected to be an important fate process based upon this compound's estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 5 hrs and 7 days, respectively. However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column. An estimated BCF of 100 suggests the potential for bioconcentration in aquatic organisms is moderate. Occupational exposure to tetra-n-butyl tin may occur through dermal contact with this compound at workplaces where tetra-n-butyl tin is produced or used. Monitoring data indicate that the general population may be exposed to tetra-n-butyl tin via ingestion of contaminated water, and dermal contact with consumer products containing tetra-n-butyl tin. (SRC)

Tetra-n-butyl tin's production and use as a rust inhibitor and chemical intermediate(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 101,400(SRC), determined from a structure estimation method(2), indicates that tetra-n-butyl tin is expected to be immobile in soil(SRC). Volatilization of tetra-n-butyl tin from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 6 atm-cu m/mole(SRC), using a fragment constant estimation method(3). However, adsorption may attenuate this process. Tetra-n-butyl tin is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 0.0048 mm Hg(4). Tetrabutyltin may be susceptible to biodegradation in soil based upon possible biodegradability of other butyltin compounds such as tri-, di- and monobutyltin species(5).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 101,400(SRC), determined from a structure estimation method(2), indicates that tetra-n-butyl tin 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 6 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 5 hrs and 7 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 2.5 yrs if adsorption is considered(5). According to a classification scheme(6), an estimated BCF of 100(SRC), from an estimated log Kow of 9.4(7) and a regression-derived equation(8), suggests the potential for bioconcentration in aquatic organisms is moderate(SRC). Tetrabutyltin may be susceptible to biodegradation in water based upon possible biodegradability of other butyltin compounds such as tri-, di- and monobutyltin species(9).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), tetra-n-butyl tin, which has a vapor pressure of 0.0048 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase tetra-n-butyl tin 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 hrs(SRC), calculated from its rate constant of 5.69X10-11 cu cm/molecule-sec at 25 °C(SRC) determined using a structure estimation method(3). It may be susceptible to direct photolysis based upon the absorption of UV light >290 nm by tri-, di-, and monobutyltin compounds(4), and should react with photochemically produced hydroxyl radicals.

Tetrabutyltin may be susceptible to biodegradation in water based upon possible biodegradability of other butyltin compounds such as tri-, di- and monobutyltin species(1), although no data concerning biodegradation of tetrabutyltin were located(SRC).

The rate constant for the vapor-phase reaction of tetra-n-butyl tin with photochemically-produced hydroxyl radicals has been estimated as 5.7X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 7 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Tetra-n-butyl tin is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups(2). It may be susceptible to direct photolysis based upon the absorption of UV light >290 nm by tri-, di-, and monobutyltin compounds(3), and should react with photochemically produced hydroxyl radicals(SRC). Tetra-n-butyltin may react with free radicals since the Sn-C bond is a good radical trap(2).

An estimated BCF of 100 was calculated for tetra-n-butyl tin(SRC), using an estimated log Kow of 9.4(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).

Using a structure estimation method based on molecular connectivity indices(1), the Koc for tetra-n-butyl tin can be estimated to be 101,400(SRC). According to a classification scheme(2), this estimated Koc value suggests that tetra-n-butyl tin is expected to be immobile in soil.

The Henry's Law constant for tetra-n-butyl tin is estimated as 6 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that tetra-n-butyl tin is expected to volatilize rapidly 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 5 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)(2) is estimated as 7 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 2.5 yrs if adsorption is considered(3). Tetra-n-butyl tin's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC); however, adsorption will attenuate this process. Tetra-n-butyl tin is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 4.8X10-3 mm Hg(4).

SURFACE WATER: Tetrabutyltin was detected and quantified in 2 of 214 samples of unfiltered subsurface water from 209 locations in Canada sampled between 1982-1985 at concentrations of 0.12 and 0.02 ppb Sn; tetrabutyltin also was detected, not quantified in another 1 of the samples (concn range from approx 3.3 parts/trillion Sn (limit of detection) to <0.01 ppb Sn (limit of quantitation))(1). Tetrabutyltin was not detected in samples from six sites in New York state and one in Michigan(1). Analysis for tetrabutyltin 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, 4 of 44 samples pos, 0.061 to 0.41 ppb, 0.192 ppb avg; subsurface, not detected in 48 samples; Baltimore Harbor, microlayer, 1 of 6 samples pos, 0.108 ppb; subsurface, 2 of 12 pos, 0.034 to 0.038 ppb; Chesapeake and Delaware Canal (a major shipping canal), microlayer, 1 of 6 samples pos, 0.526 ppb; subsurface, not detected in 12 samples; Potomac and Choptank Rivers, microlayer not detected in 11 samples; subsurface, not detected in 24 samples(2).

SEDIMENT: Tetrabutyltin was detected and quantified in 1 of 235 samples of the top 2 cm of sediment from bodies of surface water in Canada sampled between 1982-1985 at concentration of 0.02 ppm Sn (dry wt); tetrabutyltin also was detected, not quantified in another 1 of the samples (concn range from approx 3.3 ppb Sn (dry wt) (limit of detection) to <0.01 ppm Sn (dry wt) (limit of quantitation))(1).

Occupational exposure to tetra-n-butyl tin may occur through dermal contact with this compound at workplaces where tetra-n-butyl tin is produced or used. Monitoring data indicate that the general population may be exposed to tetra-n-butyl tin via ingestion of contaminated water and dermal contact with consumer products containing tetra-n-butyl tin. (SRC)

LC50 Pimephales promelas (fathead minnow) 45.2 ug/l/96 hr (confidence limit 41.6 - 49.2 mg/l), flow-through bioassay with measured concentrations, 25.3 °C, dissolved oxygen 6.8 mg/l, hardness 44.3 mg/l calcium carbonate, alkalinity 44.1 mg/l calcium carbonate, and pH 7.7.

EC50 Pimephales promelas (fathead minnow) 45.2 ug/l/96 hr (confidence limit 41.6 - 49.2 mg/l), flow-through bioassay with measured concentrations, 25.3 °C, dissolved oxygen 6.8 mg/l, hardness 44.3 mg/l calcium carbonate, alkalinity 44.1 mg/l calcium carbonate, and pH 7.7. Effect: loss of equilibrium.

Tetra-n-butyl tin's production and use as a rust inhibitor and chemical intermediate may result in its release to the environment through various waste streams. If released to air, a vapor pressure of 0.0048 mm Hg at 25 °C indicates tetra-n-butyl tin will exist solely as a vapor in the ambient atmosphere. Vapor-phase tetra-n-butyl tin 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 7 hrs. It may be susceptible to direct photolysis based upon the absorption of UV light >290 nm by tri-, di-, and monobutyltin compounds. If released to soil, tetra-n-butyl tin is expected to be immobile based upon an estimated Koc of 101,400. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 6 atm-cu m/mole. However, adsorption to soil is expected to attenuate volatilization. If released into water, tetra-n-butyl tin is expected to adsorb to suspended solids and sediment based upon the estimated Koc. Tetrabutyltin may be susceptible to biodegradation in water based upon possible biodegradability of other butyltin compounds such as tri-, di- and monobutyltin species. Volatilization from water surfaces is expected to be an important fate process based upon this compound's estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 5 hrs and 7 days, respectively. However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column. An estimated BCF of 100 suggests the potential for bioconcentration in aquatic organisms is moderate. Occupational exposure to tetra-n-butyl tin may occur through dermal contact with this compound at workplaces where tetra-n-butyl tin is produced or used. Monitoring data indicate that the general population may be exposed to tetra-n-butyl tin via ingestion of contaminated water, and dermal contact with consumer products containing tetra-n-butyl tin. (SRC)

Tetra-n-butyl tin's production and use as a rust inhibitor and chemical intermediate(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 101,400(SRC), determined from a structure estimation method(2), indicates that tetra-n-butyl tin is expected to be immobile in soil(SRC). Volatilization of tetra-n-butyl tin from moist soil surfaces is expected to be an important fate process(SRC) given an estimated Henry's Law constant of 6 atm-cu m/mole(SRC), using a fragment constant estimation method(3). However, adsorption may attenuate this process. Tetra-n-butyl tin is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 0.0048 mm Hg(4). Tetrabutyltin may be susceptible to biodegradation in soil based upon possible biodegradability of other butyltin compounds such as tri-, di- and monobutyltin species(5).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 101,400(SRC), determined from a structure estimation method(2), indicates that tetra-n-butyl tin 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 6 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 5 hrs and 7 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 2.5 yrs if adsorption is considered(5). According to a classification scheme(6), an estimated BCF of 100(SRC), from an estimated log Kow of 9.4(7) and a regression-derived equation(8), suggests the potential for bioconcentration in aquatic organisms is moderate(SRC). Tetrabutyltin may be susceptible to biodegradation in water based upon possible biodegradability of other butyltin compounds such as tri-, di- and monobutyltin species(9).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), tetra-n-butyl tin, which has a vapor pressure of 0.0048 mm Hg at 25 °C(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase tetra-n-butyl tin 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 hrs(SRC), calculated from its rate constant of 5.69X10-11 cu cm/molecule-sec at 25 °C(SRC) determined using a structure estimation method(3). It may be susceptible to direct photolysis based upon the absorption of UV light >290 nm by tri-, di-, and monobutyltin compounds(4), and should react with photochemically produced hydroxyl radicals.

Tetrabutyltin may be susceptible to biodegradation in water based upon possible biodegradability of other butyltin compounds such as tri-, di- and monobutyltin species(1), although no data concerning biodegradation of tetrabutyltin were located(SRC).

The rate constant for the vapor-phase reaction of tetra-n-butyl tin with photochemically-produced hydroxyl radicals has been estimated as 5.7X10-11 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 7 hours at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). Tetra-n-butyl tin is not expected to undergo hydrolysis in the environment due to the lack of hydrolyzable functional groups(2). It may be susceptible to direct photolysis based upon the absorption of UV light >290 nm by tri-, di-, and monobutyltin compounds(3), and should react with photochemically produced hydroxyl radicals(SRC). Tetra-n-butyltin may react with free radicals since the Sn-C bond is a good radical trap(2).

An estimated BCF of 100 was calculated for tetra-n-butyl tin(SRC), using an estimated log Kow of 9.4(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).

Using a structure estimation method based on molecular connectivity indices(1), the Koc for tetra-n-butyl tin can be estimated to be 101,400(SRC). According to a classification scheme(2), this estimated Koc value suggests that tetra-n-butyl tin is expected to be immobile in soil.

The Henry's Law constant for tetra-n-butyl tin is estimated as 6 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that tetra-n-butyl tin is expected to volatilize rapidly 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 5 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)(2) is estimated as 7 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 2.5 yrs if adsorption is considered(3). Tetra-n-butyl tin's Henry's Law constant indicates that volatilization from moist soil surfaces may occur(SRC); however, adsorption will attenuate this process. Tetra-n-butyl tin is not expected to volatilize from dry soil surfaces(SRC) based upon a vapor pressure of 4.8X10-3 mm Hg(4).

SURFACE WATER: Tetrabutyltin was detected and quantified in 2 of 214 samples of unfiltered subsurface water from 209 locations in Canada sampled between 1982-1985 at concentrations of 0.12 and 0.02 ppb Sn; tetrabutyltin also was detected, not quantified in another 1 of the samples (concn range from approx 3.3 parts/trillion Sn (limit of detection) to <0.01 ppb Sn (limit of quantitation))(1). Tetrabutyltin was not detected in samples from six sites in New York state and one in Michigan(1). Analysis for tetrabutyltin 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, 4 of 44 samples pos, 0.061 to 0.41 ppb, 0.192 ppb avg; subsurface, not detected in 48 samples; Baltimore Harbor, microlayer, 1 of 6 samples pos, 0.108 ppb; subsurface, 2 of 12 pos, 0.034 to 0.038 ppb; Chesapeake and Delaware Canal (a major shipping canal), microlayer, 1 of 6 samples pos, 0.526 ppb; subsurface, not detected in 12 samples; Potomac and Choptank Rivers, microlayer not detected in 11 samples; subsurface, not detected in 24 samples(2).

SEDIMENT: Tetrabutyltin was detected and quantified in 1 of 235 samples of the top 2 cm of sediment from bodies of surface water in Canada sampled between 1982-1985 at concentration of 0.02 ppm Sn (dry wt); tetrabutyltin also was detected, not quantified in another 1 of the samples (concn range from approx 3.3 ppb Sn (dry wt) (limit of detection) to <0.01 ppm Sn (dry wt) (limit of quantitation))(1).

Occupational exposure to tetra-n-butyl tin may occur through dermal contact with this compound at workplaces where tetra-n-butyl tin is produced or used. Monitoring data indicate that the general population may be exposed to tetra-n-butyl tin via ingestion of contaminated water and dermal contact with consumer products containing tetra-n-butyl tin. (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