IMO - Revised Recommendations for Entering Enclosed Spaces aboard Ships

8th March 2012

On 30 November 2011 the International Maritime Organisation (IMO) adopted Resolution A.1050(27) “Revised Recommendations for Entering Enclosed Spaces Aboard Ships”. The revised recommendations replace Resolution A.864(20) published in 1997.

Changes in the Revised Recommendations for Entering Enclosed Spaces aboard Ships 

The revised recommendations update and expand the previous guidance and include a number of changes as follows:

Section 2 - Definitions

Two new definitions have been included in the guidelines for an “adjacent connected space” and an “Attendant”. An “adjacent connected space” is defined as “a normally unventilated space which is not used for cargo but which may share the same atmospheric characteristics with the enclosed space such as, but not limited to, a cargo space accessway”. An “Attendant” is defined as “a person who is suitably trained within the safety management system, maintains a watch over those entering the enclosed space, maintains communications with those inside the space and initiates the emergency procedures in the event of an incident occurring”.

Section 3 – Safety Management for Entry into Enclosed Spaces

This section is new and reads as follows:

  1. “The safety strategy to be adopted in order to prevent accidents on entry to enclosed spaces should be approached in a comprehensive manner by the company.
  2. The company should ensure that the procedures for entering enclosed spaces are included among the key shipboard operations concerning the safety of the personnel and the ship, in accordance with paragraph 7 of the International Safety Management (ISM) Code.
  3. The company should elaborate a procedural implementation scheme which provides for training in the use of atmospheric testing equipment in such spaces and a schedule of regular onboard drills for crews.
  4. Competent and responsible persons should be trained in enclosed space hazard recognition, evaluation, measurement control and elimination, using standards acceptable to the Administration.
  5. Crew members should be trained, as appropriate, on enclosed space safety, including familiarisation with onboard procedures for recognizing, evaluating, and controlling hazards associated with entry into enclosed spaces.
  6. Internal audits by the company and external audits by the Administration of the ship’s safety management system should verify that the established procedures are complied with in practice and are consistent with the safety strategy referred to in paragraph 3.1” (point 1 above.)

Section 4 – Assessment of Risk

This section states that the company should carry out a risk assessment to identify all enclosed spaces on board the ship. This risk assessment should be repeated periodically to ensure it remains valid. The competent person is also reminded that the ventilation procedures for an adjacent connected space may be different from those of the enclosed space itself.

Section 6 – General Precautions

Under “General Precautions” two new points have been added to the previous guidance. The first states that entrances to enclosed spaces should be secured at all times when entry is not required. The second point is intended to minimise the risk of someone mistakenly thinking that a hatch or door that has been opened in order to ventilate an enclosed space means that the atmosphere inside is safe.  An attendant should therefore be posted at the entrance, or a suitable mechanical barrier should be placed across the opening together with a warning sign to prevent accidental entry.

The original recommendations advised that “Ships’ crew should be drilled periodically in rescue and first aid”. This sentence has been replaced with “Ships’ crews with rescue and first aid duties should be drilled periodically in rescue and first aid procedures. Training should include as a minimum:

  1. Identification of the hazards likely to be faced during entry into enclosed spaces;
  2. Recognition of the signs of adverse health effects caused by exposure to hazards during entry; and
  3. Knowledge of personal protective equipment required for entry.”

Section 7 – Testing the Atmosphere

Additional guidance in this section states that: “In some cases it may be difficult to test the atmosphere throughout the enclosed space without entering the space (e.g., the bottom landing of a stairway) and this should be taken into account when assessing the risk to personnel entering the space. The use of flexible hoses or fixed sampling lines which reach remote areas within the enclosed space, may allow for safe testing without having to enter the space”.

Although the previous recommendations contained advice on safe limits for oxygen and flammable and toxic gases, the revised text notes that “National requirements may determine the safe atmosphere range” with regard to oxygen content. A further point has been added advising that steady readings of “not more than 50% of the Occupational Exposure Limit (OEL) of any toxic vapours and gases” should be obtained prior to entry along with a remark that “It should be noted that the term Occupation Exposure Limit (OEL) includes the Permissible Exposure Limit (PEL). Maximum Admissible Concentration (MAC) and Threshold Limit Value (TLV) or any other internationally recognised terms.”

Whereas the earlier version advised that “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”, the revised text states that “It should be emphasized that the internal structure of the space, cargo, cargo residues and tank coatings may also present situations where oxygen-deficient areas may exist, and should always be suspected, even when an enclosed space has been satisfactorily tested as being suitable for entry, this is particularly the case for spaces where the path of the supply and outlet ventilation is obstructed by structural members or cargo.”

Section 8 – Precautions During Entry

The information in this section has been broadened with the addition of the following;

“Particular care should be exhibited when working on pipelines and valves within the space. If conditions change during the work, increased frequency of testing of the atmosphere should be performed. Changing conditions that may occur include increasing ambient temperatures, the use of oxygen-fuel torches, mobile plant, work activities in the enclosed space that could evolve vapours, work breaks, or if the ship is ballasted or trimmed during the work”, and that “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. Only properly trained and equipped personnel should perform rescue operations in enclosed spaces.”

Section 9 – Additional Precautions for Entry into a Space Where the Atmosphere is Known or Suspected to be Unsafe

Two new sentences have been included in this section advising that “Spaces that have not been tested should be considered unsafe for persons to enter”, and that “Persons entering enclosed spaces should be provided with calibrated and tested multi-gas detectors that monitor the levels of oxygen, carbon monoxide and other gases as appropriate”.

Section 10 – Hazards Related to Specific Types of Ships or Cargo

This section now contains a sub-section on the “Use of Nitrogen as an inert gas” which states that “Nitrogen is a colourless and odourless gas that, when used as an inert gas, causes oxygen deficiency in enclosed spaces and at exhaust openings on deck during purging of tanks and void spaces and use in cargo holds. It should be noted that one deep breath of 100% nitrogen gas will be fatal.”  Additional information can be found in MSC.1/Circ.1401 “Guidelines on Tank Entry for Tankers using Nitrogen as an Inerting Medium”. Any vessel using nitrogen including gas tankers and bulk carriers should also heed this advice.

The sub-section on “Oxygen-depleting cargoes and materials” has been amended slightly to emphasise that the list of products referred to is not exhaustive.

Appendix – Example of an Enclosed Space Entry Permit

The example of an enclosed space entry permit in the Appendix has undergone a number of minor changes:

  1. The question: “Has the space been thoroughly ventilated?” has been expanded with the addition of the words “by mechanical means?”
  2. The requirement for an oxygen content of at least 21% by volume is now accompanied by a note stating that “National requirements may determine the safe atmosphere range.”
  3. The “Pre-Entry Checks” in Section 2 were previously required to be carried out either by the person entering the space or by the authorised team leader. This requirement has been modified and the items listed are “to be checked by each person entering the space”.
  4. Sections 1, 2 and 3 of the permit were previously signed by the “Responsible person supervising entry”.  These sections are now to be signed by the “Attendant”, along with the Master or nominated person.

Members are advised to take account of IMO’s revised guidelines and ensure, so far as is practicable, that their Safety Management System (SMS) procedures and checklists for entering enclosed spaces are amended to reflect the new recommendations. Members should also consider the following advice when carrying out such a review:

Additional Enclosed Space Guidance

Often a question on board will be what constitutes an enclosed space? IMO defines an enclosed space as being one which has any of the following characteristics:

  • Limited openings for entry and exit;
  • Inadequate ventilation; and
  • Is not designed for continuous worker occupancy

The definition includes, but is not limited to, the following compartments:

  • Cargo spaces
  • Double bottoms
  • Fuel tanks
  • Ballast tanks
  • Cargo pump-rooms
  • Cargo compressor rooms
  • Cofferdams
  • Chain lockers
  • Void spaces
  • Duct keels
  • Inter-barrier spaces
  • Boilers
  • Engine crankcases
  • Engine scavenge air receivers
  • Sewage tanks

If it is unclear whether or not a particular compartment is an enclosed space, a risk assessment should be carried out in accordance with IMO recommendations to overcome any doubts. The process of carrying out a risk assessment to identify enclosed spaces should be repeated at regular intervals as circumstances may change.

IMO’s recommendations now make reference to adjacent connected spaces. For example, a forecastle store or deck house fitted with a booby hatch leading to a cargo space may be considered to be such a space. An adjacent connected space may be deficient in oxygen, or flammable or toxic gas may be present, particularly if the seal on the booby hatch or access door to the cargo space is not gas tight. It should also be borne in mind that less obvious areas of a vessel may also exhibit the characteristics of an enclosed space. For example, a recent MAIB Safety Flyer describes a situation where heavy framing on the weather deck surrounding the entrance to a cargo tank impeded the dissipation of cargo vapours.

Another MAIB Safety Flyer draws attention to the fitness of shore contractors engaged to work inside an enclosed space. If concerns arise, they should be refused entry.

Additional permits, as detailed in the vessel’s SMS, may also be required when working in enclosed spaces, such as for hot work or working from a height. The need for other permits such as these should always be considered before work inside an enclosed space is undertaken.

Potential hazards such as unguarded openings, wet or muddy surfaces and lightening holes in intermediate decks within ballast tanks should not be overlooked, nor the need for personnel to be properly equipped to minimise the risk of slips and falls.  An MAIB Investigation Report highlights an accident of this type which took place during a routine inspection of a ballast tank. Particular care must be taken by personnel in such circumstances, and sufficient lighting should be provided to enable safe movement through the space.

Personnel should never enter an enclosed space unless an enclosed space entry permit has been issued beforehand in accordance with the procedures set out in the SMS. During the pre-entry checks it should always be assumed that the space is not safe for entry until proved otherwise. Anyone who remains uneasy about whether or not an enclosed space is safe to enter after the necessary precautions have been taken should be encouraged to voice their concerns in case further action is warranted.

The IMO recommendation that “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. Only properly trained and equipped personnel should perform rescue operations in enclosed spaces” is of particular importance. It is a natural human reaction to help others in difficulty, but the urge to do so must be resisted. Instances of someone losing their life after rushing to help a colleague in trouble inside an enclosed space where neither of them followed the correct entry procedures are all too common.

Enclosed Space Entry and Rescue Drills 

Enclosed space entry and rescue drills are, at present, not required by many flag states. However, IMO is in the process of drafting amendments to SOLAS that will make enclosed space entry and rescue drills mandatory. It is anticipated that vessels will need to carry out such drills at least once every two months to ensure that crewmembers are familiar with the actions to be taken if it becomes necessary to rescue someone from inside an enclosed space. In the meantime such drills may be incorporated into the SMS and conducted regularly as a prudent precaution.

Members requiring further advice should contact the Loss Prevention department.

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