Toxicological profile
TRIBUTYLTIN
Bachelor Course Toxicology
April 10th, 2025
,Table of contents
1 Compound information and properties ............................................................... 3
1.1 Name, synonyms and identifiers ................................................................... 3
1.2 Chemical structure ...................................................................................... 3
1.3 Physical and Chemical Properties ................................................................. 3
1.4 Description, production and use ................................................................... 4
1.5 Sources of human exposure.......................................................................... 4
2 Toxicokinetic ..................................................................................................... 5
2.1 Absorption................................................................................................... 5
2.2 Distribution ................................................................................................. 5
2.3 Metabolism ................................................................................................. 5
2.4 Excretion ..................................................................................................... 5
3 Toxic effects ...................................................................................................... 6
3.1 Organ-specific toxicity .................................................................................. 6
3.2 Respiratory system....................................................................................... 8
3.3 Neuronal system .......................................................................................... 9
3.4 Immune system ......................................................................................... 11
3.5 Endocrine system ...................................................................................... 13
3.6 Development and reproduction................................................................... 16
3.7 Other (e.g., carcinogenicity, mutagenicity) ................................................... 17
4 Current regulation ........................................................................................... 18
5 Summary and conclusions ............................................................................... 18
6 References ..................................................................................................... 20
2
, 1 Compound information and properties
1.1 Name, synonyms and identifiers
Name: Tributyltin (TBT)
IUPAC Name: Tributylstannane
Common Synonyms: 4XDX163P3D, TRIBUTYL TIN, Tributlytin, HSDB 6362, EINECS 211-
704-4
Structural Identifiers: CAS 688-73-3; InChlKey PIILXFBHQILWPS-UHFFFAOYSA-N
1.2 Chemical structure
1.3 Physical and Chemical Properties
Molecular Formula: C12H27Sn
Molecular Weight: 290.05 g/mol
Appearance: Colorless liquid
Melting Point: Unknown for pure TBT (Tributyltinchloride: -9 C; Tributyltinhydride: <0
C; Tributyltinoxide: -45 C).
Boiling Point: 112.5 - 113.5 C at 8 mm Hg (When heated to decomposition it emits
acrid smoke and irritating fumes)
Solubility: Unknown for pure TBT (Tributyltinchloride: Insoluble in cold water, hydrolyzes
in hot water, soluble in common organic solvents; Tributyltinhydride: practically
insoluble, soluble in common organic solvents; Tributyltinoxide: moderately soluble,
depending on temperature and pH, soluble in lipids and in common organic solvents).
Log P (Log Kow): 3.19 – 3.84 in distilled water, 3.54 in sea water (indicating
hydrophobicity)
pKa: 6.25 (indicating that it is weakly acidic)
3
, 1.4 Description, production and use
Tributyltin (TBT) is an organotin compound, a class of organometallic chemicals where a
tin atom is covalently bonded to one or more carbon atoms. Several TBT-based
substances became commercially relevant for a variety of industrial applications, such
as agricultural pesticides, disinfecting agents and as heat stabilizers in vinyl chloride
polymers (PVC) (Kotake, 2012). The most important use of TBT was as a component in
antifouling paints applied to the hulls of ships, where it functions as a biocide agent that
prevents attachment of unwanted organisms, such as algae and barnacles. This
application was discovered by a Dutch research group (Beyer et al., 2022). In the mid-
1980’s, TBT containing naval coatings were used on over 80% of commercial ships
(Abbott et al., 2000). Despite the advantages gained by the biocidic properties of TBT,
such as a lower fuel consumption due to reduced friction, financial benefits regarding
ship maintenance and a lower risk of transporting invasive organisms (Arai et al., 2009),
major toxic impacts on the environment and human health are associated with the use
of TBT-containing antifouling paints. This resulted in a worldwide ban by the
International Maritime Organization (IMO) in 2003 (Oliveira et al., 2024). Nonetheless,
due to its chemical stability the adverse effects of TBT residues are still persistent today,
long after the global ban. The leaching of TBT from ship hulls into the marine
environment has caused a bioaccumulation of this organotin compound in sediment
layers over decades. High concentrations of sedimentary TBT are still interacting with
the surrounding environment and ecosystems and do not seem to decrease (Kim et al.,
2011).
1.5 Sources of human exposure
As previously described in Chapter 1.4, TBT has a wide variety of industrial applications
because of its stability and biocidic capacities. Human exposure occurs through both
direct and indirect pathways. Direct exposure to TBT-based substances is primarily
occupational, affecting individuals working in ship maintenance, PVC manufacturing or
agricultural sectors where residues of TBT are present. Indirect exposure occurs when
an individual is exposed to TBT through intermediate pathways and is primarily caused
by environmental contamination. The most significant route is dietary intake through the
consumption of fish and shellfish due to TBT’s lipophilic properties, specifically in
species high in the food chain, where bioaccumulation results in elevated TBT
concentrations. Additionally, contaminated soil and water sources cause further risks,
as exposure can occur through recreational activities or in some cases, through
consumption of drinking water (Antizar-Ladislao, 2008).
4
TRIBUTYLTIN
Bachelor Course Toxicology
April 10th, 2025
,Table of contents
1 Compound information and properties ............................................................... 3
1.1 Name, synonyms and identifiers ................................................................... 3
1.2 Chemical structure ...................................................................................... 3
1.3 Physical and Chemical Properties ................................................................. 3
1.4 Description, production and use ................................................................... 4
1.5 Sources of human exposure.......................................................................... 4
2 Toxicokinetic ..................................................................................................... 5
2.1 Absorption................................................................................................... 5
2.2 Distribution ................................................................................................. 5
2.3 Metabolism ................................................................................................. 5
2.4 Excretion ..................................................................................................... 5
3 Toxic effects ...................................................................................................... 6
3.1 Organ-specific toxicity .................................................................................. 6
3.2 Respiratory system....................................................................................... 8
3.3 Neuronal system .......................................................................................... 9
3.4 Immune system ......................................................................................... 11
3.5 Endocrine system ...................................................................................... 13
3.6 Development and reproduction................................................................... 16
3.7 Other (e.g., carcinogenicity, mutagenicity) ................................................... 17
4 Current regulation ........................................................................................... 18
5 Summary and conclusions ............................................................................... 18
6 References ..................................................................................................... 20
2
, 1 Compound information and properties
1.1 Name, synonyms and identifiers
Name: Tributyltin (TBT)
IUPAC Name: Tributylstannane
Common Synonyms: 4XDX163P3D, TRIBUTYL TIN, Tributlytin, HSDB 6362, EINECS 211-
704-4
Structural Identifiers: CAS 688-73-3; InChlKey PIILXFBHQILWPS-UHFFFAOYSA-N
1.2 Chemical structure
1.3 Physical and Chemical Properties
Molecular Formula: C12H27Sn
Molecular Weight: 290.05 g/mol
Appearance: Colorless liquid
Melting Point: Unknown for pure TBT (Tributyltinchloride: -9 C; Tributyltinhydride: <0
C; Tributyltinoxide: -45 C).
Boiling Point: 112.5 - 113.5 C at 8 mm Hg (When heated to decomposition it emits
acrid smoke and irritating fumes)
Solubility: Unknown for pure TBT (Tributyltinchloride: Insoluble in cold water, hydrolyzes
in hot water, soluble in common organic solvents; Tributyltinhydride: practically
insoluble, soluble in common organic solvents; Tributyltinoxide: moderately soluble,
depending on temperature and pH, soluble in lipids and in common organic solvents).
Log P (Log Kow): 3.19 – 3.84 in distilled water, 3.54 in sea water (indicating
hydrophobicity)
pKa: 6.25 (indicating that it is weakly acidic)
3
, 1.4 Description, production and use
Tributyltin (TBT) is an organotin compound, a class of organometallic chemicals where a
tin atom is covalently bonded to one or more carbon atoms. Several TBT-based
substances became commercially relevant for a variety of industrial applications, such
as agricultural pesticides, disinfecting agents and as heat stabilizers in vinyl chloride
polymers (PVC) (Kotake, 2012). The most important use of TBT was as a component in
antifouling paints applied to the hulls of ships, where it functions as a biocide agent that
prevents attachment of unwanted organisms, such as algae and barnacles. This
application was discovered by a Dutch research group (Beyer et al., 2022). In the mid-
1980’s, TBT containing naval coatings were used on over 80% of commercial ships
(Abbott et al., 2000). Despite the advantages gained by the biocidic properties of TBT,
such as a lower fuel consumption due to reduced friction, financial benefits regarding
ship maintenance and a lower risk of transporting invasive organisms (Arai et al., 2009),
major toxic impacts on the environment and human health are associated with the use
of TBT-containing antifouling paints. This resulted in a worldwide ban by the
International Maritime Organization (IMO) in 2003 (Oliveira et al., 2024). Nonetheless,
due to its chemical stability the adverse effects of TBT residues are still persistent today,
long after the global ban. The leaching of TBT from ship hulls into the marine
environment has caused a bioaccumulation of this organotin compound in sediment
layers over decades. High concentrations of sedimentary TBT are still interacting with
the surrounding environment and ecosystems and do not seem to decrease (Kim et al.,
2011).
1.5 Sources of human exposure
As previously described in Chapter 1.4, TBT has a wide variety of industrial applications
because of its stability and biocidic capacities. Human exposure occurs through both
direct and indirect pathways. Direct exposure to TBT-based substances is primarily
occupational, affecting individuals working in ship maintenance, PVC manufacturing or
agricultural sectors where residues of TBT are present. Indirect exposure occurs when
an individual is exposed to TBT through intermediate pathways and is primarily caused
by environmental contamination. The most significant route is dietary intake through the
consumption of fish and shellfish due to TBT’s lipophilic properties, specifically in
species high in the food chain, where bioaccumulation results in elevated TBT
concentrations. Additionally, contaminated soil and water sources cause further risks,
as exposure can occur through recreational activities or in some cases, through
consumption of drinking water (Antizar-Ladislao, 2008).
4
