15.5.1
Hydrogen peroxide
solutions over 60% but not over 70% by mass
15.5.1.1 Hydrogen peroxide
solutions over 60% but not over 70% by mass shall be carried in dedicated
ships only and no other cargoes shall be carried.
15.5.1.2 Cargo tanks and
associated equipment shall be either pure aluminium (99.5%) or solid
stainless steel (304L, 316, 316L or 316Ti), and passivated in accordance
with approved procedures. Aluminium shall not be used for piping on
deck. All nonmetallic materials of construction for the containment
system shall neither be attacked by hydrogen peroxide nor contribute
to its decomposition.
15.5.1.3 Pump-rooms shall
not be used for cargo-transfer operations.
15.5.1.4 Cargo tanks shall
be separated by cofferdams from oil fuel tanks or any other space
containing flammable or combustible materials.
15.5.1.5 Tanks intended
for the carriage of hydrogen peroxide shall not be used for seawater
ballast.
15.5.1.6 Temperature sensors
shall be installed at the top and bottom of the tank. Remote temperature
readouts and continuous monitoring shall be located on the navigating
bridge. If the temperature in the tanks rises above 35°C, visible
and audible alarms shall be activated on the navigating bridge.
15.5.1.7 Fixed oxygen monitors
(or gas-sampling lines) shall be provided in void spaces adjacent
to tanks to detect leakage of the cargo into these spaces. Remote
readouts, continuous monitoring (if gas-sampling lines are used, intermittent
sampling is satisfactory) and visible and audible alarms similar to
those for the temperature sensors shall also be located on the navigating
bridge. The visible and audible alarms shall be activated if the oxygen
concentration in these void spaces exceeds 30% by volume. Two portable
oxygen monitors shall also be available as back-up systems.
15.5.1.8 As a safeguard
against uncontrolled decomposition, a cargo-jettisoning system shall
be installed to discharge the cargo overboard. The cargo shall be
jettisoned if the temperature rise of the cargo exceeds a rate of
2°C per hour over a 5-hour period or when the temperature in the
tank exceeds 40°C.
15.5.1.9 Cargo tank venting
systems shall have pressure/vacuum-relief valves for normal controlled
venting, and rupture discs or a similar device for emergency venting,
should tank pressure rise rapidly as a result of uncontrolled decomposition.
Rupture discs shall be sized on the basis of tank design pressure,
tank size and anticipated decomposition rate.
15.5.1.10 A fixed water-spray
system shall be provided for diluting and washing away any concentrated
hydrogen peroxide solution spilled on deck. The areas covered by the
water-spray shall include the manifold/hose connections and the tank
tops of those tanks designated for carrying hydrogen peroxide solutions.
The minimum application rate shall satisfy the following criteria:
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.1 The product shall be diluted from the original
concentration to 35% by mass within 5 minutes of the spill.
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.2 The rate and estimated size of the spill shall be
based upon maximum anticipated loading and discharge rates, the time required to
stop flow of cargo in the event of tank overfill or a piping/hose failure, and the
time necessary to begin application of dilution water with actuation at the cargo
control location or on the navigating bridge.
15.5.1.11 Only those hydrogen
peroxide solutions which have a maximum decomposition rate of 1% per
year at 25°C shall be carried. Certification from the shipper
that the product meets this standard shall be presented to the master
and kept on board. A technical representative of the manufacturer
shall be on board to monitor the transfer operations and have the
capability to test the stability of the hydrogen peroxide. He shall
certify to the master that the cargo has been loaded in a stable condition.
15.5.1.12 Protective clothing
that is resistant to hydrogen peroxide solutions shall be provided
for each crew member involved in cargo-transfer operations. Protective
clothing shall include nonflammable coveralls, suitable gloves, boots
and eye protection.
15.5.2
Hydrogen peroxide
solutions over 8% but not over 60% by mass
15.5.2.1 The ship's shell
plating shall not form any boundaries of tanks containing this product.
15.5.2.2 Hydrogen peroxide
shall be carried in tanks thoroughly and effectively cleaned of all
traces of previous cargoes and their vapours or ballast. Procedures
for inspection, cleaning, passivation and loading of tanks shall be
in accordance with MSC/Circ.394. A certificate shall be on board the
vessel indicating that the procedures in the circular have been followed.
The passivation requirement may be waived by an Administration for
domestic shipments of short duration. Particular care in this respect
is essential to ensure the safe carriage of hydrogen peroxide:
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.1 When hydrogen peroxide is carried no other cargoes
shall be carried simultaneously.
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.2 Tanks which have contained hydrogen peroxide may
be used for other cargoes after cleaning in accordance with the procedures
outlined in MSC/Circ.394.
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.3 Consideration in design shall provide minimum
internal tank structure, free draining, no entrapment and ease of visual
inspection.
15.5.2.3 Cargo tanks and
associated equipment shall be either pure aluminium (99.5%) or solid
stainless steel of types suitable for use with hydrogen peroxide (e.g.
304, 304L, 316, 316L, 316Ti). Aluminium shall not be used for piping
on deck. All non-metallic materials of construction for the containment
system shall neither be attacked by hydrogen peroxide nor contribute
to its decomposition.
15.5.2.4 Cargo tanks shall
be separated by a cofferdam from fuel oil tanks or any other space
containing materials incompatible with hydrogen peroxide.
15.5.2.5 Temperature sensors
shall be installed at the top and bottom of the tank. Remote temperature
readouts and continuous monitoring shall be located on the navigating
bridge. If the temperature in the tank rises above 35°C, visible
and audible alarms shall activate on the navigating bridge.
15.5.2.6 Fixed oxygen monitors
(or gas-sampling lines) shall be provided in void spaces adjacent
to tanks to detect leakage of the cargo into these spaces. The enhancement
of flammability by oxygen enrichment shall be recognized. Remote readouts,
continuous monitoring (if gas-sampling lines are used, intermittent
sampling is satisfactory) and visible and audible alarms similar to
those for the temperature sensors shall also be located on the navigating
bridge. The visible and audible alarms shall activate if the oxygen
concentration in these void spaces exceeds 30% by volume. Two portable
oxygen monitors shall also be available as back-up systems.
15.5.2.7 As a safeguard
against uncontrolled decomposition, a cargo-jettisoning system shall
be installed to discharge the cargo overboard. The cargo shall be
jettisoned if the temperature rise of the cargo exceeds a rate of
2°C per hour over a 5-hour period or when the temperature in the
tank exceeds 40°C.
15.5.2.8 Cargo tank venting
systems with filtration shall have pressure/vacuum-relief valves for
normal controlled venting, and a device for emergency venting, should
tank pressure rise rapidly as a result of an uncontrolled decomposition
rate, as stipulated in 15.5.2.7.
These venting systems shall be designed in such a manner that there
is no introduction of seawater into the cargo tank even under heavy
sea conditions. Emergency venting shall be sized on the basis of tank
design pressure and tank size.
15.5.2.9 A fixed water-spray
system shall be provided for diluting and washing away any concentrated
solution spilled on deck. The areas covered by the water-spray shall
include the manifold/hose connections and the tank tops of those tanks
designated for the carriage of hydrogen peroxide solutions. The minimum
application rate shall satisfy the following criteria:
-
.1 The product shall be diluted from the original
concentration to 35% by mass within 5 minutes of the spill.
-
.2 The rate and estimated size of the spill shall be
based upon maximum anticipated loading and discharge rates, the time required to
stop flow of the cargo in the event of tank overfill or a piping/hose failure, and
the time necessary to begin application of dilution water with actuation at the
cargo control location or on the navigating bridge.
15.5.2.10 Only those hydrogen
peroxide solutions which have a maximum decomposition rate of 1% per
year at 25°C shall be carried. Certification from the shipper
that the product meets this standard shall be presented to the master
and kept on board. A technical representative of the manufacturer
shall be on board to monitor the transfer operations and have the
capability to test the stability of the hydrogen peroxide. He shall
certify to the master that the cargo has been loaded in a stable condition.
15.5.2.11 Protective clothing
that is resistant to hydrogen peroxide shall be provided for each
crew member involved in cargo-transfer operations. Protective clothing
shall include coveralls that are nonflammable, suitable gloves, boots
and eye protection.
15.5.2.12 During transfer
of hydrogen peroxide the related piping system shall be separated
from all other systems. Cargo hoses used for transfer of hydrogen
peroxide shall be marked "FOR HYDROGEN PEROXIDE TRANSFER ONLY".
15.5.3
Procedures for
inspection, cleaning, passivation and loading of tanks for the carriage
of hydrogen peroxide solutions 8-60%, which have contained other cargoes,
or for the carriage of other cargoes after the carriage of hydrogen
peroxide
15.5.3.1 Tanks
having contained cargoes other than hydrogen peroxide shall be inspected,
cleaned and passivated before re-use for the transport of hydrogen
peroxide solutions. The procedures for inspection and cleaning, as
given in paragraphs 15.5.3.2 to 15.5.3.8 below,
apply to both stainless steel and pure aluminium tanks (see paragraph 15.5.2.2). Procedures for passivation
are given in paragraph 15.5.3.9 for
stainless steel and 15.5.3.10 for
aluminium. Unless otherwise specified, all steps apply to the tanks
and to all associated equipment having been in contact with the other
cargo.
15.5.3.2 After
unloading the previous cargo the tank shall be rendered safe and inspected
for any residues, scale and rust.
15.5.3.3 Tanks
and associated equipment shall be washed with clean filtered water.
The water to be used shall at least have the quality of potable water
with a low chlorine content.
15.5.3.4 Trace
residues and vapours of the previous cargo shall be removed by steaming
of tank and equipment.
15.5.3.5 Tank
and equipment are washed again with clean water (quality as above)
and dried, using filtered, oil-free air.
15.5.3.6 The
atmosphere in the tank shall be sampled and investigated for the presence
of organic vapours and oxygen concentration.
15.5.3.7 The
tank shall be checked again by visual inspection for residues of the
previous cargo, scale and rust as well as for any smell of the previous
cargo.
15.5.3.8 If inspection
or measurements indicate the presence of residues of the previous
cargo or its vapours, actions described in paragraphs 15.5.3.3 to 15.5.3.5 shall be repeated.
15.5.3.9 Tank
and equipment made from stainless steel which have contained other
cargoes than hydrogen peroxide or which have been under repair shall
be cleaned and passivated, regardless of any previous passivation,
according to the following procedure:
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.1 New welds and other repaired parts shall be
cleaned and finished using stainless steel wire brush, chisel, sandpaper or buff.
Rough surfaces shall be given a smooth finish. A final polishing is necessary.
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.2 Fatty and oily residues shall be removed by the
use of appropriate organic solvents or detergent solutions in water. The use of
chlorine-containing compounds shall be avoided as they can seriously interfere
with passivation.
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.3 The residues of the degreasing agent shall be
removed, followed by a washing with water.
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.4 In the next step, scale and rust shall be removed
by the application of acid (e.g. a mixture of nitric and hydrofluoric acids),
followed again by a washing with clean water.
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.5 All the metal surfaces which can come into contact
with hydrogen peroxide shall be passivated by the application of nitric acid of a
concentration between 10 and 35% by mass. The nitric acid must be free from heavy
metals, other oxidizing agents or hydrogen fluoride. The passivation process shall
continue for 8 to 24 h, depending upon the concentration of acid, the ambient
temperature and other factors. During this time a continuous contact between the
surfaces to be passivated and the nitric acid shall be ensured. In the case of
large surfaces this may be achieved by recirculating the acid. Hydrogen gas may be
evolved in the passivation process, leading to the presence of an explosive
atmosphere in the tanks. Therefore, appropriate measures must be taken to avoid
the build-up or the ignition of such an atmosphere.
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.6 After passivation the surfaces shall be thoroughly
washed with clean filtered water. The washing process shall be repeated until the
effluent water has the same pH value as the incoming water.
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.7 Surfaces treated according to the above steps may
cause some decomposition when coming into contact with hydrogen peroxide for the
first time. This decomposition will cease after a short time (usually within two
or three days). Therefore an additional flushing with hydrogen peroxide for a
period of at least two days is recommended.
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.8 Only degreasing agents and acid cleaning agents
which have been recommended for this purpose by the manufacturer of the hydrogen
peroxide shall be used in the process.
15.5.3.10 Tanks
and equipment made from aluminium and which have contained cargoes
other than hydrogen peroxide, or which have been under repair, shall
be cleaned and passivated. The following is an example of a recommended
procedure:
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.1 The tank shall be washed with a solution of a
sulphonated detergent in hot water, followed by a washing with water.
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.2 The surface shall then be treated for 15 to 20 min
with a solution of sodium hydroxide of a concentration of 7% by mass or treated
for a longer period with a less concentrated solution (e.g. for 12 h with 0.4 to
0.5% sodium hydroxide). To prevent excessive corrosion at the bottom of the tank
when treating with more concentrated solutions of sodium hydroxide, water shall be
added continuously to dilute the sodium hydroxide solution which collects
there.
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.3 The tank shall be thoroughly washed with clean,
filtered water. As soon as possible after washing, the surface shall be passivated
by the application of nitric acid of a concentration between 30 and 35% by mass.
The passivation process shall continue for 16 to 24 h. During this time a
continuous contact between the surfaces to be passivated and the nitric acid shall
be ensured.
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.4 After passivation the surfaces shall be thoroughly
washed with clean, filtered water. The washing process shall be repeated until the
effluent water has the same pH value as the incoming water.
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.5 A visual inspection shall be made to ensure that
all surfaces have been treated. It is recommended that an additional flushing is
carried out for a minimum of 24 h with dilute hydrogen peroxide solution of a
concentration approximately 3% by mass.
15.5.3.11 The
concentration and stability of the hydrogen peroxide solution to be
loaded shall be determined.
15.5.3.12 The
hydrogen peroxide is loaded under intermittent visual supervision
of the interior of the tank from an appropriate opening.
15.5.3.13 If
substantial bubbling is observed which does not disappear within 15
min after the completion of loading, the contents of the tank shall
be unloaded and disposed of in an environmentally safe manner. The
tank and equipment shall then be repassivated as described above.
15.5.3.14 The
concentration and stability of the hydrogen peroxide solution shall
be determined again. If the same values are obtained within the limits
of error as in paragraph 15.5.3.10, the tank is considered to be properly
passivated and the cargo ready for shipment.
15.5.3.15 Actions
described in paragraphs 15.5.3.2 to
15.5.3.8 shall be carried out under the supervision of the
master or shipper. Actions described in paragraphs 15.5.3.9 to 15.5.3.15 shall be carried
out under the on-site supervision and responsibility of a representative
of the hydrogen peroxide manufacturer or under supervision and responsibility
of another person familiar with the safety-relevant properties of
hydrogen peroxide.
15.5.3.16 The
following procedure shall be applied when tanks having contained hydrogen
peroxide solution are to be used for other products (unless otherwise
specified, all steps apply to the tanks and to all associated equipment
having been in contact with hydrogen peroxide):
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.1 Hydrogen peroxide cargo residue shall be drained
as completely as possible from tanks and equipment.
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.2 Tanks and equipment shall be rinsed with clean
water, and subsequently thoroughly washed with clean water.
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.3 The interior of the tank shall be dried and
inspected for any residues.
Steps .1 to .3, in 15.5.3.16, shall be carried out under the supervision of the
master or the shipper. Step .3 in paragraph 15.5.3.16 shall be carried out by a person familiar with the
safety-relevant properties of the chemical to be transported and of hydrogen peroxide.
SPECIAL CAUTIONS :
1 Hydrogen peroxide decomposition may enrich the atmosphere
with oxygen and appropriate precautions shall be observed.
2 Hydrogen gas may be evolved in the passivation processes
described in paragraphs 15.5.3.9.5, 15.5.3.10.2 and 15.5.3.10.4, leading to the presence of an
explosive atmosphere in the tank. Therefore, appropriate measures must be taken to avoid
the build-up or the ignition of such an atmosphere.