Current through Register Vol. 46, No. 12, March 20, 2024
(a) General.
(1) Confined spaces where dangerous air
contaminants have been present, are present or could be introduced from
potential sources shall not be entered by any person for any reason until the
atmosphere of such confined spaces has been tested and found free of dangerous
air contaminants. Any such confined space shall be continuously maintained free
of dangerous air contaminants during any period of occupancy. If, however, due
to emergency conditions any such confined space cannot be cleared of dangerous
air contaminants by mechanical ventilation or equivalent means, any person
entering such confined space shall be provided with and shall use an approved
air line respirator, approved hose mask or approved self-contained breathing
apparatus.
(2) Whenever a confined
space is to be entered, a person who has been designated as a safety monitor
shall function as required by this Part (rule). A confined space shall not be
entered unless there is at least one other person in addition to the required
safety monitor ready to render assistance in an emergency when alerted. Such
additional person shall be located within 100 feet unobstructed walking
distance from and not more than one floor above or one floor below the access
opening of such confined space. The assigned duties of such additional person
shall be such that they will not prevent him from responding immediately to an
emergency when alerted.
(b) Preparation for entering a confined
space. Prior to entering any confined space, the following steps shall be taken
to insure the safety of the person entering:
(1) Any contents shall be removed, emptied or
drained from the confined space insofar as is possible and the interior shall
be purged by water or other equivalent means.
(2) The person entering the confined space or
a designated qualified person shall lock out the circuit breakers or switches
of all electrically operated equipment such as agitator drives, pumps and
similar equipment which is connected to or affects the confined space and could
affect the health and safety of any person in the confined space. The keys for
such locks shall be retained by the person entering the confined
space.
(3) All manhole and
clean-out covers shall be removed and the openings maintained clear of any
obstructions.
(4) All input lines
which discharge into the confined space shall be disconnected and capped or
provided with line blank flanges. The use of a single in-line valve shut-off is
prohibited as the sole means of isolating the confined space from any input
line. However, the use of a double in-line valving arrangement with a vent in
between the two valves is acceptable provided that dangerous air contaminants
are not created by such venting.
(5) Tests in the confined space for the
presence of dangerous air contaminants or lack of sufficient oxygen, or both,
where the threat of each condition exists shall be made by a designated person
who is qualified to conduct such tests by training and experience. Such tests
shall be performed using calibrated equipment of a type suitable for the air
contaminants involved. If such tests indicate that air contaminants in excess
of the concentrations listed in subpart 12-3 of this Part (rule) are present in
the confined space, the space shall be purged by mechanical ventilation until a
subsequent test indicates that the air contaminant concentration is in
compliance with subpart 12-3 of this Part (rule). If more than one type of air
contaminant is known to be present or could be introduced in the confined
space, additional tests shall be made for each contaminant. A confined space
containing air contaminants which may develop an explosion hazard shall be
purged by mechanical ventilation until tests indicate that the concentration of
air contaminants in the confined space is not more than 25 percent of the lower
explosive level of such air contaminants and that there is sufficient oxygen
available in the confined space. In lieu of purging by mechanical ventilation,
an inert atmosphere may be maintained in the confined space, provided that
control devices are used to insure that combustion or ignition of material,
including gases, cannot occur. Whenever an inert atmosphere is maintained in a
confined space, every occupant shall be equipped with an approved
self-contained breathing apparatus, an approved air line respirator or an
approved hose mask. Every occupant shall leave the confined space immediately
in the event of an interruption of the air supply to the breathing apparatus.
The inert atmosphere shall be prevented from contaminating all other work
areas, including the area of the access opening to the confined space and
adjacent areas. Maintenance of the inert atmosphere shall in no way interfere
with or prevent the emergency escape of an occupant from such a confined
space.
(6) The mechanical
ventilation system shall be so designed that the contaminants or contaminated
air is transported to some safe location, without recirculation, and the
replacement entry air does not contain dangerous air contaminants, but does
contain sufficient oxygen. The provisions of this paragraph shall also apply to
the exhausting of an inert atmosphere.
(7) Any person entering a confined space
shall be provided with and shall use the following additional safety equipment:
(i) Where the least dimension of any access
opening to a confined space is less than 24 inches, approved wrist straps or
approved noose-type wristlets shall be worn. Where the least dimension of such
access opening is greater than 24 inches, either an approved life belt,
approved safety harness, approved wrist straps or approved noose-type wristlets
shall be worn.
(ii) A lifeline, as
specified by the provisions of Industrial Code Part (Rule No.) 23, shall be
attached to such life belt, approved safety harness, approved wrist straps or
approved noose-type wristlets with the other end securely anchored outside the
confined space.
Exception:Where such a lifeline attached to approved
wrist straps or approved noose-type wristlets interferes with the performance
of the work duties of the person occupying the confined space, such lifeline
complete with safety snaps may be disconnected from the wrist straps or
wristlets provided the lifeline safety snap remains within three feet of the
person in the confined space for quick attachment to the wrist straps or
wristlets.
(iii) A safe
means of ingress and egress, such as a portable ladder, provided such means
will not obstruct the access opening.
(iv) An explosion-proof battery-operated
portable light in good working order.
(v) Non-sparking striking, chipping,
hammering or cutting tools and equipment where the confined space may contain
explosive or flammable air contaminants.
(c) Safety monitors.
(1) A person designated as a safety monitor
shall be stationed at the access opening of any confined space while such space
is occupied for any reason. The safety monitor shall maintain visual contact
with every occupant in the confined space where the construction of the
confined space permits, or shall have continuous knowledge of the activities
and well-being of every occupant of the confined space via verbal communication
or other positive means at all times. Such safety monitor may assist an
occupant of a confined space in such light duties as handling tools or supplies
or removing containers of refuse or debris provided that these tasks do not
interfere with his primary duty as a safety monitor.
(2) The safety monitor shall be an alert,
competent person, fully capable of quickly summoning the assistance of a person
or rescue team for the administration of emergency first aid treatment if
required.
(3) The safety monitor
must be physically able to assist such summoned person or rescue team in the
extrication of an occupant from a confined space under emergency
conditions.
(4) The following
emergency equipment shall be available to the safety monitor or rescue
personnel for use if required.
(i) Approved
air line respirator, approved hose mask or approved self-contained breathing
apparatus.
(ii) Explosion-proof
battery-operated portable light in good working order.
(iii) Safety equipment as specified in
subpart 12-1, section 12-1.9, subdivision (b), paragraph (7), subparagraphs (i)
and (ii) of this Part (rule).
(5) Such emergency equipment shall be located
at the access opening of the confined space or not more than 15 feet from such
opening.
(d) Operations
requiring continuous testing. If the nature of the work to be performed
produces or has the potential to produce dangerous air contaminants as
specified in this Part (rule), continuous testing shall be performed. If such
tests indicate evidence of dangerous air contaminants exceeding the
concentrations listed in subpart 12-3 of this Part (rule) or in quantities
greater than 25 percent of the lower explosive level, the occupants shall be
ordered to evacuate the confined space immediately.
(e) External alarm signal. Outside of every
occupied confined space there shall be an audible alarm signal device located
within 15 feet of the access opening. Such device may be of the portable type
and shall be maintained in good working order. When actuated, such audible
alarm shall be louder than the general background noise level and should be
capable of being heard clearly by any person located within 100 feet of the
access opening. In case of an emergency in a confined space, the safety monitor
shall immediately actuate the alarm signal. In no case shall the safety monitor
or other rescue personnel enter the confined space without first actuating the
alarm signal and, secondly, putting on his personal protective
equipment.
(f) Illumination. There
shall be installed and maintained an independent substitute emergency lighting
system in addition to the principal lighting system in any area where a
confined space is located and which is entered frequently for cleaning and
maintenance purposes. Such substitute emergency lighting system shall operate
automatically upon failure of the principal system and shall be capable of
providing distinct illumination for a period of at least 30 minutes of all
access openings of confined spaces as well as of the general surrounding area
and exits. Whenever the principal lighting system fails, the confined spaces
shall be evacuated immediately. Where any confined space is to be entered
infrequently for inspection or similar purposes, sufficient quantities of
battery-powered lights in good working order shall be provided to afford
distinct illumination at every access opening and its surrounding area and
exit. These lights shall be capable of providing illumination for a period of
time of at least one hour.