A presentation on tributyltin and its characteristics.

1. Tributyltin Compounds
Joel Emmanuel Bortoni-González
EPF
ENV 4

2. Summary
 Introduction
 Characteristics
 Prominent uses
 Quality regulations
 Toxicity
 Eco toxicity
 Arcachon Bay

3. Tributyltin
 (C4H9)3Sn
 In the form of other compounds due to its instability
with.
 Part of the aromatic hydrocarbon chemical family.
 TBTO, C24H54OSn2 is the most common compound.
Benzene
C6H6

4. Characteristics
 Colorless and with a smell similar to gasoline.
 TBTO has a slightly yellow color.
 Insoluble in water, soluble in hexane and organic solvents.
 Flammable but not explosive.
 MP: 53ºC
 BP: 193ºC
 Density of 1.103 g/ml @ 20ºC
 Breaks down slowly in the presence of oxygen, light or heat.

5. Prominent uses
 TBTO is an effective biocidal used in the preservation
of wood, cotton textiles, paper and paints for residential
homes.
 Its main use is as an antifouling agent in marine paints
for boat hulls, docks, fishnets and buoys to discourage
the growth of marine organisms.

6. Quality regulations
 In 1987 a Europe-wide ban of its use on boats of under
25 meters long was established.
 In November 1998 the IMO made the decision to
introduce a worldwide ban from January 2003.
 Pressure for a complete ban of TBT in antifouling
paints has been increasing due to evidence that it is
bio-accumulating in food chains.

7. Toxicity
 Effects of TBT products on humans: irritated skin,
headaches, colds, flu, fatigue dizziness, stomach ache,
irritation of the eye and mucous membranes and prolonged
exposure may cause liver and kidney damage.
 High levels of TBTO can affect the endocrine glands,
upsetting the hormone levels in the pituitary, gonad and
thyroid glands.
 Large doses of TBT have been shown to damage the
reproductive and central nervous systems, bone structure
and the gastrointestinal track of mammals.
 Studies have been conducted showing that TBTO causes
depression of immune functions

8. Eco toxicity
 Imposex, the development of male characteristics in
females, has been initiated by TBT exposure in several snail
species (50 ppt), the mud snail being the most significant (3
ppt).
 Molluscs, used as indicators of TBT pollution because of
their high sensitivity to those chemicals, react adversely to
very low levels of TBT (0.06-2.3 ppb of TBT).
 Some fish can degrade TBT due to special enzymes that
these fishes contain.
 TBTO has been shown to inhibit cell survival of marine
unicellular algae at very low concentrations.

9. Arcachon Bay
 1970’s: oyster production of 10,000 to 15,000 tons per
year, annual leisure vessels visit of 7,500 (8kg of TBT input
per day).
 1970: imposex discovered to affect the oyster drill
(predator).
 1976: normal spawning event, few larvae survived.
 1981: oyster production of 3,000 tons per year, annual
leisure vessels visit o 15,000.
 French controls: ban of use of TBT based paints on boats
smaller than 25 m long.