Recommendations for entering enclosed spaces aboard ships
The object of these recommendations is to encourage the adoption of
safety procedures aimed at preventing casualties to ships personnel
entering enclosed spaces where there may be an oxygen deficient,
flammable and/or toxic atmosphere.
Investigations into the circumstances of casualties that have occurred
have shown that accidents on board ships are in most cases caused by an
insufficient knowledge of, or disregard for, the need to take
precautions rather than a lack of guidance.
The following practical recommendations apply to all types of ships and
provide guidance to seafarers. It should be noted that on ships where
entry into enclosed spaces may be infrequent, for example, on certain
passenger ships or small general cargo ships, the dangers may be less
apparent, and accordingly there may be a need for increased vigilance.
The recommendations are intended to complement national laws or
regulations, accepted standards or particular procedures which may exist
for specific trades, ships or types of shipping operations.
It may be impracticable to apply some recommendations to particular
situations. In such cases, every endeavour should be made to observe the
intent of the recommendations, and attention should be paid to the risks
that may be involved.
The atmosphere in any enclosed space may be deficient in oxygen and/or
contain flammable and/or toxic gases or vapours. Such an unsafe
atmosphere could also subsequently occur in a space previously found to
be safe. Unsafe atmosphere may also be present in spaces adjacent to
those spaces where a hazard is known to be present.
2.1 "Enclosed space" means a space which has any of the following characteristics:
.1 limited openings for entry and exit;
.2 unfavourable natural ventilation; and
.3 is not designed for continuous worker occupancy,
and includes, but is not limited to, cargo spaces, double bottoms, fuel
tanks, ballast tanks, pump-rooms, compressor rooms, cofferdams, void
spaces, duct keels, inter-barrier spaces, engine crankcases and sewage
2.2 "Competent person" means a person with sufficient theoretical
knowledge and practical experience to make an informed assessment of the
likelihood of a dangerous atmosphere being present or subsequently
arising in the space.
2.3 "Responsible person" means a person authorised to permit entry into
an enclosed space and having sufficient knowledge of the procedures to
03 Assessment of risk
3.1 In order to ensure safety, a competent person should always make a preliminary assessment of any potential hazards in the space to be entered, taking into account previous cargo carried, ventilation of the space, coating of the space and other relevant factors. The competent person's preliminary assessment should determine the potential for the presence of an oxygen-deficient, flammable or toxic atmosphere.
3.2 The procedures to be followed for testing the atmosphere in the
space and for entry should be decided on the basis of the preliminary
assessment. These will depend on whether the preliminary assessment
.1 there is minimal risk to the health or life of personnel
entering the space;
.2 there is no immediate risk to health or life but a risk could
arise during the course of work in the space; and
.3 a risk to health or life is identified.
3.3 Where the preliminary assessment indicates minimal risk to health
or life or potential for a risk to arise during the course of work in
the space, the precautions described in 4, 5, 6 and 7 should be followed
3.4 Where the preliminary assessment identifies risk to life or health,
if entry is to be made, the additional precautions specified in section
8 should also be followed.
04 Authorization of entry
4.1 No person should open or enter an enclosed space unless authorised
by the master or nominated responsible person and unless the appropriate
safety procedures laid down for the particular ship have been followed.
4.2 Entry into enclosed spaces should be planned and the use of an
entry permit system, which may include the use of a checklist, is
recommended. An Enclosed Space Entry Permit should be issued by the
master or nominated responsible person, and completed by a person who
enters the space prior to entry. An example of the Enclosed Space Entry
Permit is provided in the appendix.
05 General precautions
The master or responsible person should determine that it is safe to enter an enclosed space by ensuring:
- that potential hazards have been identified in the assessment and as far as possible isolated or made safe;
- that the space has been thoroughly ventilated by natural or
mechanical means to remove any toxic or flammable gases, and to
ensure an adequate level of oxygen throughout the space;
- that the atmosphere of the space has been tested as appropriate
with properly calibrated instruments to ascertain acceptable
levels of oxygen and acceptable levels of flammable or toxic
- that the space has been secured for entry and properly
- that a suitable system of communication between all parties for
use during entry has been agreed and tested;
- that an attendant has been instructed to remain at the entrance
to the space whilst it is occupied;
- that rescue and resuscitation equipment has been positioned
ready for use at the entrance to the space, and that rescue
arrangements have been agreed;
- that personnel are properly clothed and equipped for the entry
and subsequent tasks; and
- that a permit has been issued authorizing entry.
The precautions in .6 and .7 may not apply to every situation described
in this section. The person authorizing entry should determine whether
an attendant and the positioning of rescue equipment at the entrance to
the space is necessary.
Only trained personnel should be assigned the duties of entering,
functioning as attendants, or functioning as members of rescue teams.
Ships' crews should be drilled periodically in rescue and first aid.
All equipment used in connection with entry should be in good
working condition and inspected prior to use.
06 Testing the atmosphere
6.1 Appropriate testing of the atmosphere of a space should be carried out with properly calibrated equipment by persons trained in the use of
the equipment. The manufacturers' instructions should be strictly
followed. Testing should be carried out before any person enters the
space, and at regular intervals thereafter until all work is completed.
Where appropriate, the testing of the space should be carried out at as
many different levels as is necessary to obtain a representative sample
of the atmosphere in the space.
6.2 For entry purposes, steady readings of the following should be obtained:
.1 21% oxygen by volume by oxygen content meter; and
.2 not more than 1% of lower flammable limit (LFL) on a suitably
sensitive combustible gas indicator, where the preliminary
assessment has determined that there is potential for
flammable gases or vapours.
If these conditions cannot be met, additional ventilation should be
applied to the space and re-testing should be conducted after a suitable
interval. Any gas testing should be carried out with ventilation to the
enclosed space stopped, in order to obtain accurate readings.
6.3 Where the preliminary assessment has determined that there is
potential for the presence of toxic gases and vapours, appropriate
testing should be carried out using fixed or portable gas or vapour
detection equipment. The readings obtained by this equipment should be
below the occupational exposure limits for the toxic gases or vapours
given in accepted national or international standards. It should be
noted that testing for flammability does not provide a suitable means of
measuring for toxicity, nor vice versa.
6.4 It should be emphasized that pockets of gas or oxygen-deficient
areas can exist, and should always be suspected, even when an enclosed
space has been satisfactorily tested as being suitable for entry.
07 Precautions during entry
7.1 The atmosphere should be tested frequently whilst the space is
occupied, and persons should be instructed to leave the space should
there be a deterioration in the conditions.
7.2 Ventilation should continue during the period that the space is
occupied and during temporary breaks. Before re-entry after a break, the
atmosphere should be re-tested. In the event of failure of the
ventilation system, any persons in the space should leave immediately.
7.3 In the event of an emergency, under no circumstances should the
attending crew member enter the space before help has arrived and the
situation has been evaluated to ensure the safety of those entering the
space to undertake rescue operations.
08 Additional precautions for entry into a space where the atmosphere is known or suspected to be unsafe
8.1 If the atmosphere in an enclosed space is suspected or known to be
unsafe, the space should only be entered when no practical alternative
exists. Entry should only be made for further testing, essential
operation, safety of life or safety of a ship. The number of persons
entering the space should be the minimum compatible with the work to be
8.2 Suitable breathing apparatus, e.g. of the air-line or self-
contained type, should always be worn, and only personnel trained in its
use should be allowed to enter the space. Air-purifying respirators
should not be used as they do not provide a supply of clean air from a
source independent of the atmosphere within the space.
8.3 The precautions specified in 5 should also be followed, as
8.4 Rescue harnesses should be worn and, unless impractical, lifelines
should be used.
8.5 Appropriate protective clothing should be worn particularly where
there is any risk of toxic substances or chemicals coming into contact
with the skin or eyes of those entering the space.
8.6 The advice in 7.3 concerning emergency rescue operations is
particularly relevant in this context.
09 Hazards related to specific types of cargo
9.1 Dangerous goods in packaged form
9.1.1 The atmosphere of any space containing dangerous goods may put
at risk the health or life of any person entering it. Dangers may
include flammable, toxic or corrosive gases or vapours that displace
oxygen, residues on packages and spilled material. The same hazards may
be present in spaces adjacent to the cargo spaces. Information on the
hazards of specific substances is contained in the IMDG Code, the
Emergency Procedures for Ships Carrying Dangerous Goods (EMS) and
Materials Safety Data Sheets (MSDS). If there is evidence or suspicion
that leakage of dangerous substances has occurred, the precautions
specified in 8 should be followed.
9.1.2 Personnel required to deal with spillages or to remove
defective or damaged packages should be appropriately trained and wear
suitable breathing apparatus and appropriate protective clothing.
9.2 Bulk liquid
The tanker industry has produced extensive advice to operators and crews
of ships engaged in the bulk carriage of oil, chemicals and liquefied
gases, in the form of specialist international safety guides.
Information in the guides on enclosed space entry amplifies these
recommendations and should be used as the basis for preparing entry
9.3 Solid bulk
On ships carrying solid bulk cargoes, dangerous atmospheres may develop
in cargo spaces and adjacent spaces. The dangers may include
flammability, toxicity, oxygen depletion or self-heating, which should
be identified in shipping documentation. For additional information,
reference should be made to the Code of Safe Practice for Solid Bulk
9.4 Oxygen-depleting cargoes and materials
A prominent risk with such cargoes is oxygen depletion due to the
inherent form of the cargo, for example, self-heating, oxidation of
metals and ores or decomposition of vegetable oils, animal fats, grain
and other organic materials or their residues. The materials listed
below are known to be capable of causing oxygen depletion. However, the
list is not exhaustive. Oxygen depletion may also be caused by other
materials of vegetable or animal origin, by flammable or spontaneously
combustible materials, and by materials with a high metal content:
.1 grain, grain products and residues from grain processing (such
as bran, crushed grain, crushed malt or meal), hops, malt
husks and spent malt;
.2 oilseeds as well as products and residues from oilseeds (such
as seed expellers, seed cake, oil cake and meal);
.4 wood in such forms as packaged timber, roundwood, logs,
pulpwood, props (pit props and other propwood), woodchips,
woodshavings, woodpulp pellets and sawdust;
.5 jute, hemp, flax, sisal, kapok, cotton and other vegetable
fibres (such as esparto grass/Spanish grass, hay, straw,
bhusa), empty bags, cotton waste, animal fibres, animal and
vegetable fabric, wool waste and rags;
.6 fishmeal and fishscrap;
.8 sulphidic ores and ore concentrates;
.9 charcoal, coal and coal products;
.10 direct reduced iron (DRI)
.11 dry ice;
.12 metal wastes and chips, iron swarf, steel and other turnings,
borings, drillings, shavings, filings and cuttings; and
.13 scrap metal.
When a ship is fumigated, the detailed recommendations contained in the
Recommendations on the Safe Use of Pesticides in Ships* should be
followed. Spaces adjacent to fumigated spaces should be treated as if
* Refer to the Recommendations on Safe Use of Pesticides in Ships,
approved by the Maritime Safety Committee of the Organization by
circular MSC/Circ.612, as amended by MSC/Circ.689 and MSC/Circ.746.
Failure to observe simple procedures can lead to people being
unexpectedly overcome when entering enclosed spaces. Observance of the
principles outlined above will form a reliable basis for assessing risks
in such spaces and for taking necessary precautions.
864(20) Recommendations for entering enclosed spaces aboard ships
Recommendations for entering enclosed spaces aboard ships
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RECALLING Article 15(j) of the Convention on the International Maritime Organization concerning the functions of the Assembly in relation to regulations and guidelines concerning maritime safety,
BEING CONCERNED at the continued loss of life resulting from personnel entering shipboard spaces in which the atmosphere is oxygen-depleted, toxic or flammable,
BEING AWARE of the work undertaken in this regard by the International Labour Organization, Governments and segments of the private sector,
NOTING that the Maritime Safety Committee, at its fifty-ninth session, approved appendix F to the Code of Safe Practice for Solid Bulk Cargoes concerning recommendations for entering cargo spaces, tanks, pump-rooms, fuel tanks, cofferdams, duct keels, ballast tanks and similar enclosed spaces,
NOTING FURTHER the decision of the Maritime Safety Committee at its sixty-sixth session to replace appendix F referred to above with the recommendations annexed to this resolution,
HAVING CONSIDERED the recommendation made by the Maritime Safety Committee at its sixty-sixth session,
- ADOPTS the Recommendations for Entering Enclosed Spaces Aboard Ships set out in the Annex to the present resolution;
- INVITES Governments to bring the annexed Recommendations to the attention of shipowners, ship operators and seafarers, urging them to apply the Recommendations, as appropriate, to all ships;
- REQUESTS the Maritime Safety Committee to keep the Recommendations under review and amend them, as necessary.
This permit relates to entry into any enclosed space and should be completed by the master or responsible officer and by the person entering the space or authorized team leader.
1 The permit should contain a clear indication as to its maximum period of validity.
2 In order to obtain a representative cross-section of the space's atmosphere, samples should be taken from several levels and through as many openings as possible. Ventilation should be stopped for about 10 minutes before the pre-entry atmosphere tests are taken.
3 Tests for specific toxic contaminants, such as benzene or hydrogen sulphide, should be undertaken depending on the nature of the previous contents of the space.