New Solas Regulation XI-1/7
Guidelines to facilitate the selection of portable atmosphere testing instruments for
enclosed spaces - Enters in force as of 1st July 2016.
These Guidelines refer to the instrument that is used to test the atmosphere in an enclosed
space before entry and at appropriate intervals thereafter until all work is completed. They
do not refer to a personal gas detector that is intended to be carried by an individual whilst
inside the enclosed space.
The instrument should be capable of remote sampling and detection for all gases that it is
designed for, without interference from the atmosphere or other characteristics of the
intervening space.
Introduction
The atmosphere in any enclosed space may be oxygen-deficient or oxygen-enriched and/or
contain flammable and/or toxic gases or vapors. Such unsafe atmospheres could also
subsequently occur in a space previously found to be safe. Unsafe atmospheres may also be
present in spaces adjacent to those spaces where a hazard is known to be present.
Procedure
The master or the responsible person should determine that it is safe to enter an enclosed
space by ensuring that:
a. Potential hazards have been identified in the assessment and as far as possible isolated or
made safe
b. 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
c. 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 vapors
d. The space has been secured for entry and properly illuminated
e. A suitable system of communication between all parties for use during entry has been
agreed and tested
f. An attendant has been instructed to remain at the entrance to the space whilst it is occupied
g. Rescue and resuscitation equipment has been positioned ready for use at the entrance to
the space and rescue arrangements have been agreed
h. Personnel are properly clothed and equipped for the entry and subsequent tasks
i. A permit has been issued, authorizing entry
Gases and vapors to be measured
The instrument should be capable of measuring and displaying concentrations of:
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Oxygen
Flammable gases or vapors (%Vol or %LEL)
Carbon monoxide
Hydrogen sulphide
a. The instrument should clearly and unambiguously show which gas or vapor it is measuring
(noting that the display may be switchable or menu accessible).
b. If the instrument is fitted with an alarm function, it should activate at the appropriate level
as determined by the flag State Administration.
Use of the instrument for atmosphere testing of enclosed spaces on board ships
a. The instrument should be suitably protected, having due regard for the environment and
temperatures in which it is expected to operate
b. The instrument should be capable of being easily carried
c. The instrument should be suitably protected from the ingress of dust and water
d. The minimum battery life of the instrument (with fresh batteries of recommended type)
should be 10 hours
e. The instrument should be intrinsically safe
f. The instrument display should be readable in all lighting conditions
Calibration
a. The manufacturers' instructions should have clearly defined calibration requirements.
b. If the instrument is fitted with an alarm or shutdown function that activates if the
manufacture's calibration interval is exceeded, this should not stop the instrument from
functioning during actual use and the unit should not restart once the alarm or function has
been activated.
Instruction manual
The instrument should be provided with a manual that describes its features and alarms and
explains how to calibrate, operate and maintain it. The information in this manual should be
available in the working language of the ship.
Reference
International Maritime Organization, MSC.1/Circ. 1477 – 9/6/2014