ASTM D5108-90(1996)

NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
Designation: D 5108 – 90 (Reapproved 1996)
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Organotin Release Rates of Antifouling Coating Systems in
Sea Water
This standard is issued under the fixed designation D 5108; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope extracting the organotin with toluene, washing with sodium
hydroxide, and measuring for total tin using (GF-AAS).
1.1 This test method covers the laboratory determination of
the rate at which organotin expressed as tributyltin (TBT) is
4. Significance and Use
released from an antifouling (AF) coating in synthetic sea
4.1 This test method is designed to provide a laboratory
water using graphite furnace atomic absorption spectrophotom-
procedure to measure changes in the release rates of solvent
etry (GF-AAS). This does not exclude the use of other
soluble tin (tributyl- and triphenyltin) that occur during a
analytical methodology for measurement of organotin in sea
period of immersion under specified conditions of constant
water such as gas chromatography.
temperature, pH, salinity, and low heavy-metal concentrations
1.2 The values stated in SI units are to be regarded as
in the surrounding sea water. Quantitative measurement of the
standard. The inch-pound units given in parentheses are for
release rate is necessary to help in selection of materials, in
information only.
providing quality assurance, and in understanding the perfor-
1.3 This standard does not purport to address all of the
mance mechanism.
safety concerns, if any, associated with its use. It is the
4.2 This test method serves only as a guide for organotin
responsibility of the user of this standard to establish appro-
release rates in service. Organotin release rates of antifouling
priate safety and health practices and determine the applica-
(AF) paint systems in service can vary over the life of the
bility of regulatory limitations prior to use. For specific hazard
coating system depending on the formulation and the environ-
statements, see Section 7.
ment. Differences in berthing locations, operating schedules,
2. Referenced Documents length of service, condition of paint-film surface, temperature,
pH, and salinity can affect results, Results obtained may not
2.1 ASTM Standards:
necessarily reflect actual tributyltin release rates that will occur
D 1141 Specification for Substitute Ocean Water
in service, but provide reliable comparisons of the release rate
D 1212 Test Methods for Measurement of Wet Film Thick-
characteristics of different antifouling formulations.
ness of Organic Coatings
4.3 This test method will serve to characterize the early
D 4138 Test Method for Measurement of Dry Film Thick-
release rate pattern, as well as estimate the steady state release,
ness of Protective Coatings by Destructive Means
of tributyltin from both self-polishing copolymer and free-
3. Summary of Test Method
association antifouling paints.
3.1 The candidate paint system is applied to cylindrical test
5. Apparatus
specimens. The coated specimens are placed in a tank of
5.1 Release-Rate Measuring Container—A 2-L (nominal ⁄2
synthetic sea water where the tin levels are kept low by
gal) polycarbonate container, approximately 13.5 cm (5.5 in.)
circulating the sea water through a carbon filter. At specified
in diameter and 19 cm (7.5 in.) high, fitted with three
intervals, each specimen is placed in 1500 mL of unused sea
polycarbonate rods approximately 6 mm (nominal ⁄4 in.) in
water and is rotated for 1 h. The rate of tributyltin release from
diameter to serve as baffles. Rods shall be evenly spaced on the
the paint is determined by measuring tributyltin concentrations
inside circumference of the container to prevent swirling of
in the sea water.
water with the test cylinder during rotation. The rods will be
3.2 Analysis of sea water for tributyltin is conducted by
secured to the container walls using acetone or methylene
chloride.
This test method is under the jurisdiction of ASTM Committee D-1 on Paint
5.2 Constant Temperature Bath—A temperature controlled
and Related Coatings, Materials, and Applications and is the direct responsibility of
Subcommittee D01.45 on Marine Coatings.
Current edition approved Dec. 5, 1990. Published February 1991.
2 5
Annual Book of ASTM Standards, Vol 11.02. A Nalgene Container, available from Cole-Palmer, 7425 N. Oak Ave., Chicago,
Annual Book of ASTM Standards, Vol 06.01. IL 60648, catalog number R-6761-20, or equivalent, has been found satisfactory for
Annual Book of ASTM Standards, Vol 06.02. this purpose.
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 5108
water bath capable of maintaining a temperature of 25 6 2°C equivalent with a salinity of 30 to 35 ppt.
into which one or more release rate measuring test containers 6.2 Extraction Solvent—Toluene, spectrograde or equiva-
can be placed. lent.
5.3 Holding Tank—A container of such dimensions so as to 6.3 Tributyltin Standards—Prepare standards using a stock
permit immersion of four or more test cylinders; must be solution of tributyltin chloride (reagent grade, minimum 96 %
equipped with a system to continuously circulate synthetic sea pure) in methanol (suggested concentration of approximately
water in the tank through a carbon filter. The rate of water flow 10 mg/L). The standards are acidified with acetic acid (less
and the size of the carbon filter should be selected to maintain than pH 4) to obtain a stable solution.
tributyltin concentrations below 100 μg/L. Flow rates should 6.4 Hydrochloric Acid (HCl) (10 % aqueous solution).
generally be set to obtain 2 to 8 turnovers per h. The size and 6.5 Hydrochloric Acid (HCl) (0.1N).
geometry of the tanks as well as the positioning of the inflow 6.6 Nitric Acid (HNO ) (10 % aqueous solution) can be
and outflow ports for the water circulation system should be used in place of HCl to clean labware.
selected to obtain a slow, relatively uniform flow of synthetic 6.7 Sodium Hydroxide (NaOH) (3 % aqueous solution).
sea water past all test cylinders in the tank. Maintain the pH of 6.8 Sodium Hydroxide (NaOH) (0.1N).
the synthetic sea water between 7.8 and 8.2, and the salinity 6.9 All reagents and cleaning agents used must be tin-free.
between 30 and 35 parts per thousand (ppt). The tank shall be
7. Hazards
provided with heaters to maintain the temperature between 21
7.1 Warning—Antifouling paints contain toxic materials
and 27°C (70 and 81°F).
that could cause skin and eye irritation on contact and adverse
5.4 Test Cylinders—Approximately 6.4 cm (nominal 2 ⁄2
in.) outside diameter polycarbonate pipe coated with a 10-cm physiological effects if ingested or inhaled. In the preparation
of test specimens and the application of various types of paints,
band of AF paint around the exterior circumference of the test
cylinder to provide 200 cm of paint film that can be immersed the use of appropriate protective clothing and equipment is
required consistent with local, state, and federal government
and freely rotated in the release rate measuring container. Seal
the bottom of the test cylinder with a polycarbonate disc using regulations, and recognized industrial and technical standards.
Do not flush spills, overspray, and unused material down the
acetone, methylene chloride, or a polycarbonate cement so as
to form a watertight joint. Do not coat the bottom 1 to 2 cm of drain, but should be dispose of as hazardous waste.
7.2 See antifouling paint supplier’s Material Safety Data
the test cylinder. The test cylinder shall be of such height so
Sheet.
that a rotating device can be attached to rotate the cylinder and
the upper open end of the cylinder is above the level of the test
8. Calibration and Standardization
container immersion liquid to prevent entry of the immersion
8.1 Prepare three standards throughout the range of the
liquid into the test cylinder.
quantification limit to 100 μg of tin per litre by dilution in
5.5 Test Cylinder Rotating Device—The device shall be
toluene of a stock solution of tributyltin chloride (96 % pure) in
capable of rotating the test cylinder in the release rate measur-
methanol. Include one standard with a concentration of ap-
ing container at 60 6 5 r/min. No part of the device shall be
proximately 50 μg of tin per litre. An alternate range of
immersed in sea water.
concentrations may be used when appropriate.
5.6 Centrifuge Tubes, 50-mL capacity, with screw closures
8.2 Prepare synthetic sea water spiked with three concen-
(or disposable bottles, culture tubes, separatory funnels, etc.)
trations of TBT in the range of 10 to 50 μg of tin per litre by
made of polycarbonate, TFE flourocarbon, or borosilicate
spiking with stock solution of tributyltin chloride in methanol.
glass.
When the concentration of tin extracted in toluene exceeds 100
5.7 Mechanical Shaker, with appropriate holders.
μg/L appropriate dilution should be employed to keep it within
5.8 Dispensers, automatic or repeating, for reagents.
the limits of the calibration curve (0 to 100 μg/L).
5.9 Pipets, with disposable polypropylene tips.
8.3 Operate the graphite furnace in accordance with manu-
5.10 Graphite Furnace, atomic absorption spectrophotom-
facturer’s instructions. Optional conditions are described in
eter (GF-AAS) with automatic sampler.
Appendix X1.
5.11 pH Meter, with a mercury/mercurous chloride (Hg/
8.4 Analyze the following:
Hg Cl ) electrode.
2 2
8.4.1 At the beginning of each instrument run, perform
5.12 Appropriate Volumetric Flasks.
analysis of the toluene blank and standards in toluene in order
6. Reagents and Materials
to establish that the response of the instrument is linear. Plot
6.1 Synthetic Sea Water—Substitute ocean water in accor- separate calibration curves for each analysis of the standards
dance with Section 6 of Specification D 1141 or a proprietary (peak height absorbance versus tin concentration), and calcu-
late the slope, intercept, and coefficient of determination for
each curve using least squares regression or another appropri-
Boekel Water Baths, Models 148003 and 148004 available from Boekel
ate procedure.
Industries Inc., 509-T Vine St., Philadelphia, PA 19106, or equivalent, have been
8.4.2 Sea Water Blank—Extract and analyze as specified for
found satisfactory for this purpose.
A six-paddle stirrer, Model 300, manufactured by Whitaker Medical Mfg. Co.,
test samples to establish baseline.
Phipps and Bird Div., 8741 Landmark Rd., Richmond, VA 23228, or equivalent, has
8.4.3 Spiked Sea Water Samples—Extract and analyze as
been found satisfactory for this purpose.
specified for test samples to determine extraction efficiency.
Oak Ridge Tubes, available from Cole-Parmer, or equivalent, have been found
satisfactory for this purpose. Recovery must be 90 to 110 %.
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
Contact ASTM International (www.astm.org) for the latest information.
D 5108
8.4.4 If changing the graphite tube during a run is necessary, holding tank daily. Adjust the pH if necessary using either 0.1
analyze the blank and standards in toluene to ensure proper N NaOH or 0.1 N HCl. Quantitate salinity every 14 days and
response and linearity before continuing the sample analysis. adjust if necessary. Determine TBT concentrations weekly.
8.5 Determine the tin concentration of individual test When TBT levels increase, change the carbon filter before the
samples with reference to the 50 μg/L calibrating standard TBT concentration exceeds 100 μg/L. More frequent monitor-
analyzed immediately after those test samples. ing of synthetic sea water may be necessary in Some instances
to maintain the specified environmental conditions.
9. Procedure
9.8 After 1, 3, 7, 10, 14, 21, 24, 28, 31, 35, 38, 42, and 45
9.1 Organotins have a strong tendency to adsorb on certain
days, transfer all cylinders in given batch into individual
glass or plastic surfaces. Therefore, all labware (glass or
measuring containers containing 1500 mL of fresh synthetic
polycarbonate) used for organotin release measurements must
sea water. Randomly assign cylinders (control and painted) to
be treated as follows: clean thoroughly by soaking in 10 % HCl
measuring containers at each leaching. When transferring
or HNO for a minimum of 6 h. Rinse labware thoroughly with
3 cylinders, lift the cylinder out of the holding tank, allow sea
distilled water and allow to dry. Cleaning can also be accom-
water to drain off, install the cylinder into the rotating device,
plished by soaking in concentrated HCl for ⁄2 h. Prepare all
and submerge the painted area into the sea water. Immediately
samples, blanks, and standards in labware treated in this
start rotation of the cylinder at 60 6 5 r/min, and continue
manner. Disposable materials (pipet tips, centrifuge tubes, etc.)
rotation for 60 min. When transferring the cylinders, do not
do not have to be acid-washed before use.
touch or in any way damage the paint film, and do not allow the
9.2 Prepare the exposure surfaces (200 cm ) of three repli-
paint surface to dry. Complete the transfer as quickly as
cate test cylinders to provide a suitable surface for adhesion of
possible (generally, in less than 5 min).
the paint system to be applied. Mask the surfaces to remain
9.9 If testing beyond the minimum (45 days) length require-
uncoated (including the bottom 1 to 2 cm of the exterior
ment is desired, the study may be extended to 73 days. During
circumferential surface of the test cylinder).
the extended test, remove the cylinders from the holding tank
9.3 Paints shall be manufactured a minimum of seven days
every 3 to 4 days to make a measurement of the leach rate.
prior to testing. Also, test paints shall not be allowed to age
9.10 At the completion of the cylinder rotation, immediately
beyond the manufacturer’s recommended shelf life. Provide
remove the cylinder from the measuring tank and return it to
typical storage conditions during aging, that is, sealed in a
the holding tank. Pipet a 25-mL subsample of the sea water into
container commonly used for sale and held at 20 to 30°C.
a 50-mL centrifuge tube containing sufficient 10 % HCl to
9.4 Apply one or more coats of antifouling p
...