| Entering Enclosed or Confined Spaces, Cont'd. |
| Page 2 of 2 |
| Testing for Toxic Gases |
 The
presence of certain gases and vapours on chemical tankers
and gas carriers is detected by fixed or portable gas or
vapour detection equipment. The readings obtained by this
equipment should be compared with the occupational
exposure limits for the contaminant given in
international industry safety guides or the latest
edition of the Health and Safety Executive Guidance Note
EH-40 Occupational Exposure Limits. These occupational
exposure limits provide guidance on the levels of
exposure to toxic substances which should not be exceeded
if the health of persons is to be protected. However, it
is necessary to know for which chemical a test is being
made in order to use the equipment correctly and it is
important to note that not all chemicals may be tested by
these means. When a toxic
chemical is encountered for which there is no means of
testing then the additional requirements specified in
Section "Additional Requirements for Entry into a
Space where the Atmosphere is Suspect or known to be
Unsafe" should also be followed . A
combustible gas indicator will probably not be suitable
for measuring levels of the gas at or around its
occupational exposure limit, where there is solely a
toxic, rather than a flammable, risk. This level will be
much lower than the flammable limit, and the indicator
will probably not be sufficienty sensitive to give
accurate readings. |
| Use of a Permit-to-Work System |
| Entry
into a dangerous space should be planned in advance and
use should preferably be made of a 'permit-to-work'
system. If, during the course of the operation,
unforeseen difficulties or hazards develop, the work
should be stopped and the space evacuated so that the
situation can be fully assessed. Permits should be
withdrawn and only issued after the situation has been
re-assessed. 'Permits-to-work' should be revised as
appropriate, Details of the arrangements to be followed
in a 'permit-to-work' system are described in Web Page "Permit-to-work Systems"
which includes a specimen of a 'permit-to-work'. For
situations for which a well established safe system of
work exists a check-list may exceptionally be accepted as
an alternative to a full 'permit-to-work ' provided that
the principles of the 'permit-to-work' system are covered
and the risks arising in the dangerous space are low. On expiry of
the 'permit-to-work', everyone should leave the space and
the entrance to the space should be closed or otherwise
secured against entry or alternatively, where the space
is no longer a dangerous space, declared safe for normal
entry. |
| Procedures and Arrangements Before Entry |
| Access
to and within the space should be adequate and well
illuminated . No matches,
welding or flame cutting equipment, electrical equipment
or other sources of ignition should be taken or put into
the space unless the master or responsible officer is
satisfied that it is safe to do so. In all cases
rescue and available resuscitation equipment should be
positioned ready for use at the entrance to the space.
Rescue equipment means breathing apparatus together with
fully charged spare cylinders of air, life lines and
rescue harnesses, and torches or lamp, approved for use
in a flammable atmosphere, if appropriate. A means of
hoisting an incapacitated person from the confined space
should also be readily available when appropriate. The number
of persons entering the space should be limited to those
who actually need to work in the space and who could be
rescued should an emergency occur. At least one
attendant should be detailed to remain at the entrance to
the space whilst it is occupied. A system of
communication should be agreed and tested by all involved
to ensure that any person entering the space can keep in
touch with the person stationed at the entrance. A system of
communication should be established between the attendant
at the entrance to the space and the officer on watch. Before entry
is permitted it should be established that entry with
breathing apparatus is possible. The extent to which the
use of breathing apparatus or life lines or rescue
harnesses would cause any difficulty of movement within
any part of the space, or would cause problems if any
incapacitated person had to be removed from the space,
should also be examined. Lifelines of
rescue harnesses should be long enough for the purpose
and be easily detachable by the wearer should they become
entangled, but should not otherwise come away from the
rescue harnesses. |
| Procedures and Arrangements During Entry |
|
Ventilation should continue during the period that the
space is occupied and during temporary breaks. In the
event of a failure of the ventilation system any persons
in the space should leave immediately. The
atmosphere should be tested periodically whilst the space
is occupied and persons should be instructed to leave the
space should there be any deterioration in the
conditions. If
unforeseen difficulties or hazards develop, the work in
the space should be stopped and the space evacuated so
that the situation can be re-assessed. If a person
in a space feels in any way adversely affected he should
give the pre-arranged signal to the attendant standing by
the entrance and immediately leave the space. When
available a rescue harness should be worn to facilitate
recovery in the event of an accident. Should an emergency occur the general (or
crew) alarm should be sounded so that back-up is
immediately available to the rescue team. |
| Additional Requirements for Entry into a Space where the Atmosphere is Suspect or Known to be Unsafe |
| If the
atmosphere is considered to be suspect or unsafe to enter
without breathing apparatus, then the space should only
be entered if it is essential for testing purposes, the
working of the ship, for the safety of life or for the
safety of the ship. The number of persons entering the
space should be the minimum compatible with the work to
be performed. Breathing
apparatus should always be worn. Respirators cannot be
used as they do not provide a supply of clean air from a
source independent of the atmosphere within the space. Except in
the case of emergency, or
where impracticable because movement in the space would
be seriously impeded, two air supplies as described in
Section below should be available to the wearer of the
breathing apparatus who is required to work in a
dangerous space. The wearer should normally use the
continuous supply provided from outside the space and he
should immediately make his way out of the space should
it be necessary to change over to the self-contained
supply. During
occupation of the space, precautions should be taken to
safeguard the continuity of the outside source of air to
the wearer of breathing apparatus. Special attention
should be given to supplies originating from the Engine
Room. Where remote
testing of the space (as recommended in Section above) is
not reasonably practicable, or where a brief inspection
only is required, a single air supply may be acceptable
provided prolonged presence in the space is not required
and the wearer of the breathing apparatus is so situated
that he can be hauled out immediately in case of emergency. Rescue
harnesses should be worn. Wherever practicable lifelines
should be used. Lifelines should be attended by a person
stationed at the entrance who has been trained how to
pull an unconscious person from a dangerous space. Where
the dangerous space to be entered requires the possible
use of hoisting equipment to effect rescue, arrangements
should be made to ensure that persons would be available
to operate it as soon as necessary. When
appropriate, portable lights and other electrical
equipment should be of a type approved for use in a
flammable atmosphere. Should there
be any hazard due to chemicals, whether in liquid,
gaseous or vapour form, coming into contact with the skin
and/or eyes then protective clothing should be worn. |
| Drills and Rescue |
| Regular
drills simulating the rescue of an incapacitated person
from a dangerous space should be conducted to prove the
feasibility of the ship's rescue plan under different and
difficult circumstances. A real-weight dummy may be used
for this purpose. If necessary, the space selected should
be made safe for the exercise. Alternatively drill may be
held, for operational convenience, in non-dangerous
spaces provided that these spaces realistically simulate
conditions expected in actual dangerous spaces on the
ship. A drill should normally be held soon after signing
on a new crew or if there has been a substantial change
in crew members. Each drill should be recorded in the
official log book. Any attempt
to rescue a person who has collapsed within a space
should be based on a pre-arranged plan. Every ship will
have its own individual problems each of which may
require a different rescue procedure, and the plan should
take into account the design of the ship and of the
equipment and manpower on board. Allocation of personnel
to relieve or back-up those first into the space should
also be borne in mind. If there are
indications through the agreed system of communication or
otherwise, that the person in the space is being affected
by the atmosphere, the person outside the space should
immediately raise the alarm. ON
NO ACCOUNT SHOULD THE PERSON STATIONED AT THE ENTRANCE TO
THE SPACE ATTEMPT TO ENTER IT BEFORE ADDITIONAL HELP HAS
ARRIVED. NO ONE SHOULD ATTEMPT A RESCUE WITHOUT WEARING
BREATHING APPARATUS AND A RESCUE HARNESS AND, WHENEVER
POSSIBLE, USE OF A LIFELINE. If air is
being supplied through an air line to the person who is
unwell, a check should be made immediately that his air
supply is being maintained at the correct pressure. On reaching
an incapacitated person, unless he is gravely injured,
e.g. a broken back, he should be removed from the
dangerous space as quickly as possible. It is emphasized,
however, that restoration of the casualty's air supply at
the earliest possible moment has always to be the first
priority. |
| Breathing Apparatus and Resuscitation Equipment |
| No one
should enter a space, even to effect a rescue, where the
atmosphere is unsafe or suspect without wearing breathing
apparatus. The two air
supplies normally to be available to the wearer of a
breathing apparatus working in a dangerous space will
usually comprise a continuous supply from outside the
space and a self-contained supply to enable the wearer to
escape to a safe atmosphere in the event of difficulty
with, or failure of, the continuous supply. It should not
be necessary to remove any part of the equipment or any
protective clothing to change over to the self contained
supply. Equipment
for use with two air supplies may consist of:- (a) a conventional self-contained breathing apparatus of the open circuit compressed air type or (b) a compressed air line breathing apparatus incorporating an emergency self-contained supply. The compressed air line breathing apparatus should be of the demand valve type. The capacity
of the self-contained supply should be sufficient for the
wearer of the breathing apparatus to escape to a safe
atmosphere. When determining this capacity it should be
recognized that if under stress or in difficult
conditions the wearer's breathing rate may be in excess
of the nominal breathing rate of 40 litres per minute. Where the
supply of air comes from outside the space, the
responsible officer should make sure that it is
continuous and is available only to those working in the
space. Pipeline or hoses supplying air should be placed
so that they are not likely to be so distorted that
supply might be interrupted or damaged. If the purpose
for which such air lines are used is not immediately
apparent to persons not engaged in the entry, then
notices should be posted at appropriate positions. When a
mechanical driven pump is being used it should frequently
be checked carefully to ensure that it continues to
operate properly. Any air pumped directly into a pipeline
or put into reserve bottles requires to be filtered and
should be as fresh as possible. Pipelines or hoses used
to supply air should be thoroughly blown through to
remove moisture and freshen the air before connection to
breathing apparatus and face masks. It is essential that
where the air supply is from a compressor sited in a
machinery space, the engineer of the watch be informed so
that the compressor is not shut-down until the work is
completed. Everyone
likely to use breathing apparatus should be instructed by
a competent person in its proper use. The Master,
or responsible officer, and the person about to enter the
space should undertake the full pre-wearing check and
donning procedures recommended in the manufacturer's
instructions. In particular they should check:-1./ that there will be sufficient clean air at the correct pressure; 2./ that low pressure alarms are working properly; 3./ that the facemask fits correctly against the user's face so that, combined with pressure of the air coming into the mask, there will not be an ingress of oxygen deficient air or toxic vapours when the user inhales. It should be noted that facial hair or spectacles may prevent the formation of an air-tight seal between a person's face and the facemask; 4./ that the wearer of the breathing apparatus understands whether or not his air supply may be shared with another person and if so is also aware that such procedures should only be used in an extreme emergency; 5./ that when work is being undertaken in the space the wearer should keep the self-contained supply for use when there is a failure of the continuous supply from outside the space. When in a
dangerous space:-1./ No one should remove his own breathing apparatus. 2./ Breathing apparatus should not be removed from a person unless it is necessary to save his life. It is
recommended that resuscitators of an appropriate kind
should be provided where any person may be required to
enter a dangerous space. Where entry is expected to occur
at sea the ship should be provided with appropriate
equipment. Otherwise entry should be deferred until the
ship has docked and use can be made of shore side
equipment. |
| Maintenance of Equipment |
| All
breathing apparatus, rescue harnesses, lifelines,
resuscitation equipment and any other equipment provided
for use in, or in connection with, entry into dangerous
spaces, or for use in emergencies, should be properly
maintained, inspected periodically and checked for
correct operation by a competent person and a record of
the inspections and checks should be kept. All items of
breathing apparatus should be inspected and checked for
correct operation before and after use. Equipment
for testing the atmosphere of dangerous spaces, including
oxygen meters, should be kept in good working order and,
where applicable, regularly serviced and calibrated. Due
regard should be paid to manufacturer's recommendations
which should always be kept with the equipment. |
| Training, Instruction and Information |
|
Employers should provide any necessary training,
instruction and information to employees in order to
ensure that the requirements of the Entry into Dangerous
Spaces Regulations are complied with. This should
include:- 1./ recognition of the circumstances and activities likely to lead to the presence of a dangerous atmosphere, 2./ the hazards associated with entry into dangerous spaces, and the precautions to be taken, 3./ the use and maintenance of equipment and clothing required for entry into dangerous spaces, 4./ instruction and drills in rescue from dangerous spaces. |
| Statutory Regulations |
| The
Merchant Shipping (Entry into Dangerous Spaces)
Regulations 1988 place obligations on the Master of a
ship and his employer to ensure that procedures for safe
entry and working in dangerous spaces are clearly laid
down and observed on board the ship, and on persons
entering or remaining in a dangerous space to do so only
in accordance with these procedures. In carrying out
these duties full account must be taken of the principles
and guidance described in this Web Page. |
| Ends |
