POINT EXTRACTION

Sector specific guidance No. 2
POINT
EXTRACTION
Paintshop
Engine room
Workshop
The Danish Maritime Occupational Health Service
2001

Copyright: The Danish Maritime Occupational Health Service
ISBN number 87-986883-8-3
Print: JBK Offset ApS, Ishøj, Denmark
Text: Jens Voxtrup Petersen, CASA and Bjarne Pless, BST Aarhus
Drawings: Pelle Søborg
Production: Tegneriet ApS, Copenhagen
Translation: Joanna Thompson
Published by
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Amaliegade 33 B
DK-1256 Copenhagen K
Denmark
Phone: +45 33 11 18 33
Fax: +45 33 11 14 60
www.seahealth.dk
E-mail: info@seahealth.dk
Iver C. Weilbach & Co. A/S
Toldbodgade 35
DK-1253 Copenhagen K
Denmark
Phone: +45 33 13 59 27
Fax: +45 33 93 59 27
E-mail: nautical@weilbach.dk

Why publish sector specific guidance
on point extraction?
Airborne pollution is an undesirable yet unavoidable
consequence of human activities. If a person,
in the course of his work, comes into contact with
harmful fumes or toxic vapours from chemicals, his
health can be adversely affected. Pollution can
have harmful effects on the mucus membranes,
the skin and on breathing. It can cause both acute
effects as well as long-term, chronic effects. Shortness
of breath and loss of consciousness are examples
of acute effects, while asthma, chronic
bronchitis and cancer can be the results of more
long-term exposure.
As a starting point, the law requires that any work
on board a merchant vessel should be carried out
in an entirely appropriate way with regard to health
and safety. This means that persons may not/
should not be exposed to unnecessary harmful influences
that, in either the short or the long term,
can have bad effects on their health.
Consequently, representatives of the shipping industry
have collaborated in preparing this sector
specific guidance. The purpose has been to establish
a form of sound and accepted practice in the
elimination of airborne pollution by means of point
extraction.
The guidelines have been submitted to the Danish
Maritime Authority and any comments are included
in the text.
Legislation
The guidelines are based on the following:
• Legal notice no. 554 of 21st June 2000 on Safety at Sea, with subsequent amendments.
• Directive B from the Danish Maritime Authority on the construction and equipping of vessels etc.
Chapter B II-4: The design and equipping of workrooms and workplaces. 1st January 2001.
• The Danish Maritime Authority’s technical regulation no. 6 of 3rd July 1997: On mechanical extraction
from a closed area used for handling paints, and from workplaces on ships.
Prevention with point extraction and ventilation
The best prevention is naturally to entirely avoid airborne pollution, e.g. by changing the working
process or by changing to other products that do not pollute. A good form of prevention can also be
achieved by eliminating pollution by means of mechanical point extraction. In certain cases it is not possible
to eliminate the pollution in a sufficiently effective way. In these cases, damage to health must be
prevented by the use of suitable personal protection.
Sector specific guidance, The Danish Maritime Occupational Health Service:
Point extraction - Why publish sector specific guidance on point extraction?
3

When should point extraction and room
ventilation be established?
Mechanical forms of point extraction should be designed
to efficiently reduce airborne pollution. It is
not sufficient to reduce airborne pollution to a possible
limit value, if the pollution is actually unnecessary
pollution. Forms of extraction should
be, as far as possible, established in direct connection
to the polluting working process.
Even though extraction is effective, some forms of
pollution on account of their character or of the
character of the working process itself, can bypass
the extraction point and in this way spread to the
working area. This, for instance, can be the case
with welding. In such circumstances, point extraction
should be supplemented with ventilation at the
workplace.
Furthermore, in many situations small widespread
sources of pollution can occur in areas where it is
not reasonable or not possible to establish extraction
at each individual part of the working process.
In such cases, ventilation at the workplace should
also be established.
Air in and air out
Ventilation plants should normally be set up with balanced amounts of air, i.e. that the amount of fresh
air that is introduced corresponds to the amount of air extracted. On the other hand, in workrooms
where it is undesirable to allow airborne pollution from surrounding areas, overpressure should be
maintained, that is to say that more air is blown into the room than is sucked out.
The additional air should ensure an effective replacement of the air that is extracted. The air that is let
in should be fresh and should have a suitable temperature. It would be ideal if the replacement air did
not result in draughts in places where crewmembers are present (the populated zone). By fresh air is
meant here that this should be the best possible exterior air from the surrounding area. The air is taken
into the area in such a way that there is no danger of a short circuit. A short circuit means that the inlet
air (replaced air) would be polluted with air from other sources, e.g. from the funnel.
Explanation of terms
This guideline uses a number of terms, which are also used in the legislation:
• Work room: Any area of the ship where work is carried out, such as on the bridge, engine room, galleys,
control rooms, workshops, paint shops, offices or similar areas.
• Fixed workplace: The place in a work room or other area where work is regularly carried out, such
as at work tables, machines, cleaning basins, pressure test stands, cooking areas and places where
paint is mixed and the relevant working tools are cleaned etc.
• Separate mechanical suction: Mechanical suction systems that are not connected to other ventilation
systems.
• Mechanical point extraction: Extraction that removes airborne particles, vapours and gases,
aerosols and similar forms of pollution as close to the source as possible.
• Unnecessary effects: Effects, which can be considerably reduced in extent and against which it appears
reasonable to initiate preventative measures.
• Open deck: A deck that is entirely open above and on at least two of its sides.
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Sector specific guidance The Danish Maritime Occupational Health Service:
Point extraction - When should point extraction and room ventilation be established?

Figure 1
Point extraction should provide the air with suitable velocity so that pollution can be trapped and
conducted away from persons (induction speed)
Requirements as to mechanical extraction
• If a working process at a fixed workplace generates
dust, vapours, gases, aerosols or similar,
which are unnecessary, harmful to health,
explosive or irritating in some way, then fixed
mechanical point extraction must be established.
The room should have a supply of fresh
air from an open deck (replacement air).
• Consequently, point extraction should be established
at welding sites, pressure testing
stands, cleaning basins used for the washing
of engine parts, cooking areas in galleys,
large-scale dish washers and similar fixed
workplaces where substances and materials
are handled and the tools used in these
processes are cleaned etc.
• Point extraction should have a suitable induction
speed (away from the person, see figure
1), which is dependent on the type of pollution
in question. The following examples can be
mentioned: Welding 0.5-1.0 metres per second,
cleaning basins (heated and unheated)
0.2-0.5 metres per second, mixing/-cleaning
areas in the paint shop 0.2-0.5 metres per
second.
• At workplaces that cannot be considered
fixed places and where the same effects as
stated under the first point can occur, portable
suction equipment and/or suitable personal
protection should be used.
• The extracted air must be conducted to a free
deck and must not be led back into the work
room or any other rooms on the ship via the
ventilation systems (re-circulation)
• All extraction systems positioned at fixed
workplaces should be equipped with some
form of operational indication that can warn
of insufficient functional ability.
Sector specific guidance The Danish Maritime Occupational Health Service:
Point extraction - When should point extraction and room ventilation be established?
5

How to make point extraction
doors, from the inlet of replacement air etc. It is still
necessary, however, to consider crosscurrents of air
when positioning the tornado.
From a tornado hood, which is 1 meter wide, about
1,000 cubic metres per hour must be extracted in
order to create an induction speed of about 0.25
metres per second.
Extraction duct on a mobile swing arm
Figure 2
An extraction duct (extraction head) can eliminate
pollution in the immediate proximity of the opening
of the duct. This means that it should be relatively
precisely positioned in relation to the source of the
pollution. The question of whether or not the process
generates heat should also be considered.
Figure 3
Tornado
The Tornado system consists of a specially
constructed hood. By means of the positioning of
the extraction and assisted by an air control a horizontal
spiral movement, which is extremely stable, is
created. When the tornado hood is correctly dimensioned,
completely covers the worktable and is
switched on, the necessary air velocity and direction
will be achieved. This applies whatever the
crewmember is engaged in doing, whether the process
generates heat or not, and regardless of at
which part of the table the crewmember carries out
the working process.
The amount of air that can be extracted through
the extraction duct depends on the size of the duct
and the distance to the source of the pollution. In
order to be able to eliminate pollution from a welding
operation at a distance of 30-40 cm or at a mixing
table, the pipe connection to the extraction
duct should be about 160 mm and the volume of
extraction should be about 1,000 cubic metres per
hour. If the extraction duct can be kept at about 10
cm from a welding operation, it would be enough
with a 50 mm pipe, a small extraction duct and a
volume of air amounting to 200 – 400 cubic metres
per hour.
Rear edge extraction (slit extraction)
At a fixed worktable, pollution can be eliminated
with the help of an extraction slit positioned on the
rear edge of the table. Such a slit extractor should
be precisely dimensioned if it is to have the desired
effect. The catch velocity is highest directly over the
table and is rapidly reduced with increased height.
As the tornado consists of a hood with a rear plate
and some side plates, a certain degree of protection
against cross currents is provided, e.g. from open
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Sector specific guidance The Danish Maritime Occupational Health Service:
Point extraction - How to make point extraction

This method can be quite effective in eliminating
"cold" pollution such as vapours from cold cleaning
basins. The method cannot be used, however,
if heat is generated through the process. Neither is
the method suitable if the source of pollution occurs
slightly above the surface of the table, as for
example, when stirring paint in the large paint containers.
The method is extremely sensitive to
crosscurrents of air.
second should be extracted, corresponding to
about 125 cubic metres per hour per kW. As in the
case of other types of point extraction, extractor
hoods are extremely sensitive to cross currents of
air.
The necessary volume of extraction air depends on
the length of the slit and on the distance between
the work process and the slit, but in general, it
would be between 1,000 and 2,000 cubic metres/per
hour.
Extractor hoods
When heat is generated in connection with pollution,
e.g. at a cooker in the galley, an extractor
hood may be used. The extractor hood should be
positioned so that the distance between the upper
side of the cooker and the lower side of the hood is
as short as possible and the size of the hood
should exceed the size of the cooker by about 25
cm on all free sides.
Figure 4
The necessary extraction volume depends on the
transmission to e.g. the stove. For each kilowatt
supplied to the normal stove, about 35 litres per
Figure 5
Important things to remember:
It is important to be aware of the exact type of pollution that should be eliminated with point extraction.
If it is hot welding fumes, the point extraction must be positioned at a point above the welding site. On
the other hand, if the pollution stems from vapours released by stirring or mixing paint, there is no heat
generated by this process, so it is useless to attempt to eliminate the pollution at a higher point by
means of an extractor hood.
In many engine rooms and workshops, strong currents of inlet air can occur (turbulence). This means
that pollution, regardless of whether it is hot or cold airborne pollution can be spread around the area.
In such areas it is impossible to get point extraction to work efficiently. The still air movement is necessary
in order that point extraction can work effectively and this can be assessed in connection with a
workplace evaluation. A protective screen can solve this.
Sector specific guidance The Danish Maritime Occupational Health Service:
Point extraction - How to make point extraction
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How to make point extraction
Encapsulation
The most efficient form of point extraction is to encapsulate
the process and make sure that there is
negative pressure within the encapsulation. The
better the encapsulation, the smaller the volume of
air it is necessary to extract.
Re-circulation
In general, all air that is extracted from a polluting
process should be led to the outside and no shortcircuiting
may occur, or the polluted air will be
drawn in again via openings, blowers etc. In many
cases, this means that the outlet air from the engine
room must be conducted up through the casing.
In a few individual cases (e.g. when pressure testing
fuel valves), it is permitted to purify the air and
re-conduct it back into the room (re-circulation). In
other special cases, it may also be permitted to
conduct the polluted air a short distance up inside
the casing, though this requires an exemption from
the Danish Maritime Authority.
Figure 6
Suggestions for point extraction in a paint shop
Efficient point extraction should be established at
fixed work places in the paint shop. This can be
achieved by means of the following:
• Tornado
• Extraction duct
• Rear edge extraction
The tornado principle is the most efficient. When the
tornado hood is positioned over the worktable and
switched on, it will create the necessary air velocity
and air current direction regardless of whether the
operation concerns stirring, mixing or pouring from
one container to another. By employing a worktable
that has been adjusted to different heights, both extraction
and ergonomics (working positions) will be
improved.
An extraction duct can create the necessary induction
speed over a radius of 30-40 cm. This means
that the duct must be placed close to the paint container
and must be moved when pouring from one
paint container to another. As this is not easy for one
person to do in practice, the task is often neglected
and consequently the method is not very effective.
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Sector specific guidance The Danish Maritime Occupational Health Service:
Point extraction - How to make point extraction

Rear edge extraction can be used for the purpose,
but in many cases it is not sufficient, since in most
cases pollution is not generated at table height but
at a somewhat higher point over the table.
The volumes of extracted air with all three methods
will normally be over about 1,000 cubic metres
per hour, which in most cases will meet the
Danish Maritime Authority’s requirement that the air
in a paint shop should be replaced at least six times
every hour.
As a risk of explosion is present, the electrical
equipment that is used in paint shops should be explosion-proof.
At the same time, it must be possible
to close down the ventilation system from outside
the room. The release button should be placed in
connection with the release for the required firefighting
equipment.
Figur 7
Requirements regarding paint shops and storerooms
A paint shop is an area where paint, organic solvents and non-inflammable liquids are handled and
where used containers are stored. With regard to floor space, the room should be large enough for one
person. In any concrete evaluation of the area, however, the amount of paint used, the types of paint
and whether or not minor repairs are also carried out in the room, will be taken into account. The legislative
requirements include:
• The room must have access from a open deck or a ro/ro deck and should have the required ventilation
as well as being designed for the purpose, including having a free flooring area of at least 4
square metres. (For new ships built after 1st January 2001)
• The workroom for the handling of paint etc. should be equipped with some form of mechanical point
extraction at the fixed workplace. The frequency of air replacement (change of air) in the room
should be at least 6 times per hour.
• Point extraction should have a suitable induction speed of between 0.2-0.5 metres per second at
mixing and cleaning areas.
• Storerooms that are solely used for the storage of paint, organic solvents, inflammable liquids etc.
must be equipped with a form of room ventilation that replaces the air at least 6 times per hour.
Sector specific guidance The Danish Maritime Occupational Health Service:
Point extraction - How to make point extraction
9

Suggestions for extraction in engine rooms
and workshops
Welding in fixed workplaces
The principle requirement to extraction from a welding
operation is that it should create an effective
air movement away from the crewmember towards
the extraction. During the working process, extremely
high temperatures are generated. This
means that the extraction should take place on the
opposite side of the item being welded in relation
to the crewmember and slightly raised over the
welding station. These conditions can be met both
by a tornado or an extraction duct.
Extractor duct
The extractor duct can be mounted on a swing arm
or can be fixed by means of magnets. Depending
on the size, the duct can eliminate pollution from a
welding operation at a distance of between 10 cm
(small duct) and 30-40 cm (large duct), if it is correctly
mounted. In most situations, this will solve
the problem. If the welding operation is of longer
duration, this should be taken into account by
moving the extractor duct along as the welding
operation progresses.
The tornado principle was, in fact, developed for
precisely this purpose. With this principle, the
crewmember does not need to move the point extraction
while he is engaged in welding – as long as
the welding takes place on the side of the worktable
covered by the tornado hood.
Welding at non-fixed workplaces
In the case of welding operations around the ship
(in closed areas or where the air is still), the requirements
as to extraction are the same as mentioned
above.
Figure 8
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Sector specific guidance The Danish Maritime Occupational Health Service:
Point extraction - Suggestions for extraction in engine rooms and workshops

Figure 9
Mobile extractor
The only possibility of eliminating pollution is to use
a mobile ventilator with flexible hoses and a suitable
extractor duct. It is possible to find ventilators
that can extract a small amount of air at high pressure
and here the small extractor ducts can be
utilised.
There are also other ventilators that can handle
larger amounts of air at a lower pressure, which
means that larger extractor ducts can be used. The
advantage of these larger ducts is that they can
trap pollution at greater distances.
Sector specific guidance The Danish Maritime Occupational Health Service:
Point extraction - Suggestions for extraction in engine rooms and workshops
11

Suggestions for extraction in engine rooms and
workshops
Figure 10
Grinding
The use of grinders causes a great deal of pollution
in the form of cutting and grinding dust as well as
possible gases from the surface treatment operation.
This type of pollution ought to be removed by
means of point extraction.
It is possible to mount various extractor ducts
directly onto the grinder, but they only have a positive
effect if the surfaces being ground are horizontal.
They have practically no effect when welding
edges or when materials are being cut and, in
fact, only get in the way.
During welding, it is necessary to use the extractor
ducts or the tornado principle at the fixed workplaces.
On the other hand, it must be admitted that
neither of these methods can totally eliminate the
pollution. It is important that a breathing apparatus
is always used while carrying out these operations.
should have a filter that prevents the grinding dust
being led into the ducts, as there is a risk that the
ducts and the ventilator could become blocked.
Encapsulation of the grindstone
The grindstone/grinding machine should be encapsulated
as much as possible in order that the
extraction is effective. Many of the machines on
the market are encapsulated and equipped with a
suction pipe. In many cases the encapsulation can
easily be improved.
The necessary amount of air from a disc grinder or
a grinding machine would be about 400 to 1,000
cubic metres per hour, depending on the width and
the encapsulation.
In the engine room or in the workshop, there is often
a disc grinder or a grinding machine. These
should be equipped with point extraction that
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Sector specific guidance The Danish Maritime Occupational Health Service:
Point extraction - Suggestions for extraction in engine rooms and workshops

Testing of fuel valves
When fuel valves are tested, very small amounts of
extremely fine spray oil fumes can occur. These
must be eliminated before they reach the
crewmember’s breathing zone.
Since the process does not need to take place in
an open area, it should be enclosed and in fact this
is the only correct method of dealing with the
problem.
To implement encapsulation that is more or less
air-free, it is necessary only to remove a very small
quantity of air. Mostly this will be under 100 cubic
metres per hour. This air must be led out into the
open air.
Other polluting working processes
There are other working processes that ought to be
evaluated for the possibility of pollution. One example
is the changing of fuel oil filters where, when
the filter is opened, certain amounts of oil aerosols
can rise up into the crewmember’s breathing zone.
The same thing can happen when, for example,
rotor caps and hot engines are inspected.
One possible solution is to use a mobile ventilator
(the same type as that used when welding) and
lead the air from this to a fixed suction tube. It is not
permitted to re-circulate extracted air, even though
it may have been cleaned through a filter.
One possibility is to use an ejector pump and an oil
filter (the same type that is used in a breathing
apparatus) and subsequently lead the very small
amount of air back into the room. This kind of
equipment is produced by several manufacturers
and in principle is approved by the Danish Maritime
Authority.
Room extraction in general
Since point extraction is not capable of eliminating all the pollution generated by a process, it is always
preferable that there is general extraction in all workshops, testing stations etc. The amount of air that
should be extracted cannot be fixed on a general basis. This will depend on factors such as the process
and on the extent that crewmembers use point extraction.
Sector specific guidance The Danish Maritime Occupational Health Service:
Point extraction - Suggestions for extraction in engine rooms and workshops
13

Suggestions for suction over cleaning
processes
On a ship, there will always be a number of engine
parts etc. that regularly have to be cleaned and this
can be done in several ways.
Washing machines and ultrasound basins
The most appropriate method of cleaning engine
parts etc. is to use closed washing machines, in
which the type of extraction that empties the machine
of hot steam before it is opened, has been
established.
One possibility that has recently become more
widespread is the use of ultrasonic basins. The
cleaning water in these is not so harmful to health
as the oil products that were previously used, and
if the temperature in the basin is kept down to 35-
40 degrees Centigrade, problems should not arise.
The use of compressed air in connection with
cleaning work ought to be reduced to a minimum,
since a normal point extraction is seldom strong
enough to catch the aerosols generated by this.
Ordinary cleaning basins
Point extraction should be established in connection
with the "ordinary" cleaning basins, from
where vapours are released. Since the cleaning liquid
is not heated, the problem can be solved in
various ways:
• Tornado system
• Rear edge extraction (slit extraction)
• Suction funnel
On the other hand, if the temperature is increased
to e.g. 80 degrees Centigrade, which often happens,
the hot steam from the basins could result in
considerable damage to the mucus membranes
and this means that point extraction should be established.
As it is the heat from the heated basins that is the
problem, the only solution is to eliminate the vapours
by means of an extractor fan, or even better,
a tornado hood.
The tornado hood can be established with a relatively
broad slit so that there is still space for a
crane hook to get in over the basin.
An ordinary extractor fan can also be used, but this
is more sensitive to crosscurrents of air and it
should therefore be equipped with plates down to
the basin, preferably on three of the sides.
Figure 11
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Sector specific guidance The Danish Maritime Occupational Health Service:
Point extraction - Suggestions for suction over cleaning processes

The tornado principle is the most effective. When
the tornado hood is positioned over the basin and
is switched on, the necessary air velocity and
direction will be established. Another advantage
is that it can be equipped with a slit in the front
and top plates, so that a crane hook can get in
over the basin.
A rear edge extractor can also be used, but this is
more sensitive to any cross currents. At the same
time, it is likely that, if the distance from the rear
wall to the front of the basin is relatively large,
then greater amounts of air will have to be used
than with a tornado.
In the case of very small cleaning basins, it is possible
to use an extractor duct placed either on a
swing arm or with magnets.
Figure 12
Suggestion for suction in the galley
In the galley, it is necessary to establish point extraction in the form of an extractor fan over cookers,
deep fryers, ovens etc. See figure 5 and the example on page 20.
The amount of air used should be adapted to the actual consumption. It is not unusual that about 1,000
cubic metres of air per hour is removed from a small galley. In a small room it can be a problem to supply
replacement air without exposing crewmembers to draughts and without the extraction effect being
ruined by cross currents of air.
Sector specific guidance The Danish Maritime Occupational Health Service:
Point extraction - Suggestions for suction over cleaning processes
15

Checking correct functioning and giving
instructions
All extraction systems should be equipped with
operational indications for malfunction. This means
that crewmembers should be able to see whether
suction is in progress and that the system functions
sufficiently well to eliminate the type of pollution
in question.
The crewmembers should be given instructions as
to how these operational indicators work, as well
as instructions on what to do if the extraction is
not sufficient.
Smoke pipettes/ smoke tubes are recommended
for the testing of the efficiency of the suction. The
"cold" smoke is blown out at a typical place of
pollution and the movement of the smoke can be
followed.
Maintenance
Figure 13
The easiest and cheapest method of establishing
an operational indication is to use a U-pipe manometer,
which shows the pressure in the duct
system.
In cases where blocking can occur at the extraction
point e.g. extractor fans, this solution is not
sufficient. Here it is necessary to mount a gauge in
the duct system with a connected U-manometer.
Any form of mechanical point extraction should be
regularly cleaned and maintained. It is recommended
that a drawing of the extractor system
along with data on air volume and inspection routines
should be kept on file.
A supplier should provide detailed and complete
directions for use of a ventilation plant. These
should include the necessary operational and
maintenance instructions as well as a set of main
drawings.
When a large-scale plant is ordered, it should be a
matter of course that the plant is delivered fully
operational with test results that prove that the
plant functions efficiently. This should be checked
before use.
Figure 14
During internal cleaning or repairs to ducts or
similar where harmful substances are released,
each person concerned should use a breathing
apparatus.
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Sector specific guidance The Danish Maritime Occupational Health Service:
Point extraction - Checking correct functioning and giving instructions

Read more about it
• Legal notice no. 554 of 21st June, with subsequent amendments.
• Directive A from the Danish Maritime Authority. Technical regulation on the working environment on
ships.
• Directive B from the Danish Maritime Authority. Technical regulation on the construction and equipping
of vessels etc. Chapter ll-4 The design and equipping of workrooms and workplaces.
• Directive B from the Danish Maritime Authority. Technical regulation on the construction and equipping
of vessels etc. Chapter ll-1, Construction – building, interior planning and stability, machinery and
electrical equipment, also Chapter ll-2, Construction – fire prevention, discovery and extinguishing of
fires.
• Technical regulation no. 6 of 3rd July 1997 on mechanical extraction from closed areas used for the
handling of paint etc. and from workplaces on ships.
Home pages:
• The Danish Maritime Authority: www.sofartsstyrelsen.dk
• The Danish Maritime Occupational Health Service: www.seahealth.dk
Sector specific guidance The Danish Maritime Occupational Health Service:
Point extraction - Read more about it
17

Examples
Example 1 – Washing machine
This washing machine is equipped with an extractor at the
top. It has been installed in an engine workshop on a Danish
passenger vessel built in 1978. The item to be washed, is
placed in the basket, which is then pushed into the machine.
Large, heavy engine parts can be placed in the washing machine
by means of a running conveyor, so it is not necessary
to lift them.
Example 3 – Encapsulated washing basin
An extractor has also been fitted into the top of this washing
basin. The basin is used for cleaning smaller engine parts in
the engine workshop. The plexi-glass plate closes downwards,
so that steam does not escape into the area. This solution
is also particularly well suited for use in areas with
strong crosscurrents.
18
Example 2 – Encapsulated washing basin
An extractor has been fitted into the top of the encapsulation
on a washing basin. The washing basin, which has been
placed in an engine workshop, is used to clean smaller machine
parts. When something is washed in the basin, the
plexi-glass plate comes down and closes over the basin so
that steam does not escape into the area. This solution is
particularly suitable for areas with strong crosscurrents.
Guidelines for the shipping industry The Danish Maritime Occupational Health Service:
Point extraction - Examples
Example 4 – Pressure testing stand
An extractor has been fitted into the right side of the pressuretesting
stand, which is used to test fuel valves and is positioned
in the engine workshop. The valve is fitted into the top
of the stand and during the testing it is possible to see the
process through the plexi-glass.

Example 5 – Transportable local suction
Transportable local suction can be used in connection With
tasks to be carried out at random places around the ship. It is
particularly suitable for welding jobs outside the welding
workshop or where there is no permanent local suction. In addition,
it can be used to ventilate tanks before entry.
Example 7 – Tornado
This tornado has been installed in a paint shop. One half of the
mixing table can be adjusted in height so that the upper edge
of the paint container is always at the same level, regardless
of whether the container holds 20 litres or 5 litres of paint. The
control air is taken direct from the area, while extracted air is
conducted out into the open air. The tornado screen is
equipped with a u-pipe manometer, so that the operator can
check the efficiency of the extraction process.
Example 6 – Swing-arm extractor with suction duct
This swing-arm with a suction duct has been installed in a
welding workshop. When welding is in progress, the suction
can be adjusted to the best possible position to catch the
fumes containing welding dust.
Example 8 – Grinding machine
This grinder is placed in an engine workshop. A suction duct
has been fitted to the back of the grinder so that part of the
pollution is led away from the operator. It is also a good idea
to utilise the same principle on other similar machines. The
best effect of this suction process is achieved by encapsulating
the grinder/machine as much as possible.
Guidelines for the shipping industry The Danish Maritime Occupational Health Service:
Point extraction - Examples
19

Example 9 – Local suction in the galley
An extractor hood has been fitted over the cooker in the galley.
The extractor hood is about 20 cm larger than the cooker
on all sides, so that pollution is effectively eliminated.
Example 10 – Rear-edge extractor
This washing basins is positioned in the engine room. In order
to have space to submerge large engine parts in the basin, a
rear-edge extractor has been fitted onto the basin. This makes
sure that any pollution is absorbed away from the person
working at the basin.
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Guidelines for the shipping industry The Danish Maritime Occupational Health Service:
Point extraction - Examples