Table Of ContentConfined Space Entry
An AIHA Protocol Guide
Second Edition, 2001
American Industrial Hygiene
Association
Fairfax, Virginia
This bwk was developed by experts with background, training, and experience in
conatlled spaces, workmg with information and conditions existing at the time of
publication. The Amedcan Industrial Hygiene Association (ALHA), as publisher,
and the authoxs have been dihgent in ensuring that the material and methods
d & dia book reflect prevailing occupational health and safety and
indusltal hygjene practices. It is possible, however, that certain procedures
&cum4 will require modification because of changing federal, state, and local
regulations, or heretofore unknown developments in research.
AIHA and the authors disclam any liability, loss, or risk resulting directly or
iditem Enam use of the practices and/or theories &cussed in this book.
Morewq, it is the reader's responsibility to stay infomed of any ch- federal,
state, or l dxe gulations that might affect the matd'eontained herein, and the
policjes adopted specifically in the reader's workplace.
Specific mention of manufacturers and products in this book does not represent
an endorsement by AIHA.
Copyright 2001 by the American Industrial Hygene Association. All rights reserved. No part of this publication
may be reproduced in any form or by any other means - graphic, electronic, or mechanical, includmg photo-
copying, taping, or information storage or retrieval systems - without prior written consent of the publisher.
ISBN 0-932627-08-4
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Stock No. 207-OC-95
An AIHA Protocol GuiTe
T
his book was developed by experts and local regulations, or heretofore unknown
with background, training, and developments in research.
experience in industrial hygiene and AIHA and the authors Qsclaim any liabihty,
occupational safety with information loss, or risk resulting duectly or indirectly from
and conditions existing at the time of publication. use of the practices and/or theories discussed in
The American Industrial Hygiene Association ths book. Moreover, it is the reader’s
(AIHA), as publisher, and the authors have been responsibdtty to stay informed of any changmg
dhgent in ensuring that the material and methods federal, state, or local regulations that might
addressed in this book reflect prevailing affect the material contained herein, and the
occupational health and safety and industrial policies adopted specifically in the reader’s
hygene practices. It is possible, however, that workplace.
certain procedures dmussed wdl require Specific mention of manufacturers and
moQfication because of changing federal, state, products in this book does not represent an
endorsement by AIHA.
V
Acknowledgments ................................................................................................................................................................. iv
About the Edltor ................................................................................................................................................................... iv
Preface ...................................................................................................................................................................................... v
Chapter 1: Introduction ................................................................................................................................................. 1
Chapter 2: Terminology ................................................................................................................................................ 3
Chapter 3: Managing the Confined Space Environment ......................................................................................... 9
Chapter 4 The Written Confined Space Entry Program ....................................................................................... 13
Chapter 5: Hazard Assessment ................................................................................................................................... 23
Chapter 6: Training Program Development ............................................................................................................ 35
Chapter 7: Confined Space Rescue Plans ................................................................................................................. 39
Chapter 8: Atmospheric Instrumentation & Monitoring ....................................................................................... 43
Chapter 9: Confined Space Vendation ..................................................................................................................... 55
Appendix A Sample Forms ........................................................................................................................................... 65
Appendix B: Entry Permits and Written Certifications .............................................................................................. 69
Appenh C: Confmed Space Equipment Lst ............................................................................................................ 95
Appendix D: Confined Space Resources ...................................................................................................................... 99
Appendix E: OSHA Permit-Required Spaced Standard 29 CFR 1910.146 ...................................................... 105
Appendix F Permit Space Entry Procedure Example .......................................................................................... 119
Appendx G: Creating a Safer Confined Space Environment ............................................................................... 125
Appendix H Medical Suitability for Confmed Space Work ................................................................................... 127
Appendlx I Recordkeeping ........................................................................................................................................ 129
Appendix J: Sample Training Course Outhe ......................................................................................................... 131
...
Lu
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he American Industrial Hygiene Associa- achieving compliance may not provide an adequate
tion (AIHA) Conjned Space Enty Protocol level of safety.
Guide, Second Edition, was developed by the Those who fall within a regulation’s purview,
AIHA Confined Spaces Committee and however, are not prohibited from tahng additional
contains practical information about worhng in strategies to improve safety. The additional precau-
confined spaces. The target audience is not only entry tions may be voluntarily adopted for a number of
supervisors, attendants, entrants, and rescuers, but also reasons. For example, these may be work practices
those who write or administer confined space pro- that are characteristic to a particular industry, or there
grams. The Committee’s goal is to prevent confined may be approaches that an individual employer’s
space worker deaths and injuries. How? By educating experience has shown to be useful. Moreover, those
people and reducing the likehood that those who having to address unique or challengmg situations are
enter or work around confined spaces will get into well-advised to go beyond the minimum require-
situations threatening their safety or health. Toward ments.
that end, we urge employers to incorporate the Guide?
information within their own confined space pro- Is Entry Required?
grams. Further, this Guide can be used to answer
Although this Guide focuses on improving the safety
questions about a variety of issues, rangmg from what
of confined space entry procedures, the AIHA
“lunited entry and exit” means to how to evaluate
Confined Spaces Committee strongly advocates
confined space rescue team preparation.
avoiding actual entry whenever possible. The most
desirable, and usually the safest, alternative is to find a
Regulations Set Minimum Standards
way to do the work without entering the confined
In the United States, confined space entry can be space. Practical solutions exist for many situations.
regulated at both the Federal and State levels. In some For instance, install remote meter &splays to avoid
locations, it may even be regulated at the local level. entering pits, extend valve handles outside under-
Regardless, the fact is that health and safety regulations ground vaults, or use flexible wiring and tubing on
establish only minimum stanahrdr of performance. Such submersible sump pumps so they can be withdrawn
regulations cannot possibly address all situations and from the outside for cleaning and repair.
circumstances that will be encountered. Furthermore,
regulations may not keep pace with changes in Where Entry Cannot Be Avoided
industry and technology. Consequently, simply
Entry, however, cannot be avoided for many mainte-
nance, construction, or inspection activities. When that
is the case, explore options for ehnating features of
a space that increase its hazard potential. Moreover,
NOTE: While h s G uid is oriented toward industrial
design new structures or re-configure already existing
occupational exposure in confined spaces, and
fachties to remove elements that cause them to be
frequently refers to employers, employees, and
confined spaces. For example, changing the entry
workers, its information should be used by anyone
method from a ladder to a standard stairway may
performing this type of work (e.g., self-employed
improve accessibility to the point where a space is no
contractors, farmers, and even homeowners).
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longer considered a confined space. Such modlfica- Whether your confined space program is being
tions often have the double benefit of improving developed or is already in place, the chances are that
safety and reducing administrative (compliance) you or someone in your organization have questions
burdens. about some aspect of this complex topic. What
Finally, if confined space entry is absolutely should be included in a written program? What
necessary, the use of good work practices and well- training is needed? How does the employer design an
designed procedures will reduce the risks associated entry permit? What should an outside rescue service
with the entry. The Confined Spaces Committee agreement include? What medlcal issues should be
advocates identifying these hazards and solutions in evaluated for confined space workers? This manual
advance. We suggest begnning such efforts with the provides guidance on these and other important
strategy of makmg the space safe for the worker questions.
rather than simply trylng to make the worker safe for The Guzdei real strength is its practical approach.
the space. Thls is seen particularly in the many sample documents
(e.g., permits, written certifications, rescue-related
Contribution of the Guide forms), detailed program content lists (e.g., training,
written program and procedure elements, medlcal
This Guidt is neither focused on compliance, nor is its
evaluation, recordkeeping), and descriptions of specific
usefulness h t e dt o general industry. Although the
activities (e.g., vendation techniques, designing entry
Occupational Safety and Health Administration
permits and training programs, selecting and using
confined space regulation serves as a frequent point of
atmospheric monitors). Those features, as well as a
reference, the knowledge, skdls, and procedures
comprehensive resource list, will equip the Guides users
discussed have application in any confined space
to tackle confined space program and procedure issues.
environment, regardless of the industry or geographic
location.
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T
he following terms and definitions are the work being performed may affect condtions
intended to serve only as a point of in the space as the job proceeds.
reference; they will not match those used Knowing how to use the safety equipment - and
by all organizations involved in confined understandmg its limitations.
space work. The marine and mining industries, for Knowing the signs and symptoms of exposure to
example, approach confined spaces dlfferently than physical and chemical hazards likely to be present
general industry. Their practices involve proven in the space.
methods that efficiently address their particular Knowing what conditions are and are not permit-
confined space problems, and these dfferences are ted in the space during entry.
reflected in the terminology used. Confined space Remaining outside the permit space(s) and
work in other industries, such as agriculture, are not maintaining communication with the entrants.
yet specifically regulated. Persons worhng in those Recognizing likely hazards outside the permit
industries may nevertheless benefit from selectively space.
using others’ proven practices (and even their termi- Recognizing when an entrant is impaired or
nology), depending on the nature of the exposure and endangered.
the type of space. Initiating rescue or other emergency response
To determine how these practices may apply to a activities when needed.
given situation, first consult the Federal standards or Keeping all equipment and the work site orderly.
other established good practices pertaining to your Keeping unauthorized personnel away from the
jurisdiction or industry (e.g., ANSI or NFPA consen- entry point.
sus standards). The following terms relate most closely
to regulations and pdelines developed for general None of these duties, however, may interfere
industry and, as a result, apply to the greatest number with the primary duty of monitoring the confined
of workers. space entrants. Further, if attendants must leave their
post without first being relieved by another qualified
Authorized attendant attendant, all entrants must first exit the permit space.
The authorized attendant must never enter the space
An indtvidual who is stationed outside one or more
to attempt a rescue unless relieved by another atten-
spaces and monitors the authorized entrants and
dant - and then, only if trained, equipped, and
performs all attendant’s duties in the employer’s
authorized to conduct a rescue.
permit space program.
The attendant’s primary function is to protect the
Authorized entrant
entrants in the confined space. To do this, the atten-
dant must have a good understandmg of confined An employee who is authorized by the employer to
space entry hazards and procedures, and proficiently enter a permit space.
perform a variety of duties. These include: The entrant’s primary function is to perform
b Understandmg the hazards that may be encoun- work inside the confined space. In addtion, they must
tered during entry activities. perform their duties in a manner that contributes to
b Understanding how the materials being used and their own safety during the job. Notice that many of
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the entrant required sktUs and duties are the same as for Following the entry procedures established by the
the attendant and the job supervisor. This is simply written program and entry permit.
because all those who are involved with entry must Assuring that team members perform their duties
work as a team; as a result, they must have some in accordance with the training they have received.
knowledge and abilities in common. The entrant’s Making a written, pre-entry determination that
required skills and duties include: permit space hazards have been fully evaluated.
Understanding the hazards that may be encoun- Ensuring that the entry permit is complete and
tered during entry, accurate.
Understanding how the materials being used and Assuring that acceptable entry conditions are
the work being performed may affect condltions maintained while the space is occupied.
in the space as the job proceeds. Verifying the avadabdity of rescue services and the
Knowing how to use the safety equipment (includ- means for summoning them.
ing PPE) and understandmg its lirmtations. Terminating the entry and canceling the entry
Knowing the signs and symptoms of exposure to permit when the work. is completed or when a
physical and chemical hazards present in the space. prohibited condltion arises.
Knowing what conditions are and are not permit-
ted in the space during entry. Confined space
Following the entry procedures established by the
written program and entry permit.
A space that:
Remaining in communication with the attendant,
1. Is large enough and so configured that a
who must be notified of any emergency or
person can bodily enter to perform
unacceptable condltion that arises in the space.
assigned work;
Evacuating the confined space immediately if
2. Has limited means for entry or exit; and
symptoms, warning signs, or unacceptable condl-
3. Is not designed for continuous
tions arise, or if ordered to do so.
occupancy.
Keeping all equipment and the work area in the
space orderly.
Some examples that may meet this definition
include: bins, pits, silos, tanks, ship holds, tunnels,
Authorized entry supervisor
trenches, ducts, pipes, boilers, tank cars, cookers,
The person, such as the employer, foreman, or crew reactor vessels, manholes, hoppers, vaults, and sewers.
chef, responsible for determining if acceptable entry While other definitions for “confined space” have
conditions are present at a permit space where entry is been developed and used over the years by various
planned, for authorizing entry and overseeing entry organizations and industries, this one is both appropri-
operations, and for terminating entry, ate and practical. Under this definition, the determina-
The entry supervisor has overall responsibhty for tion of whether a space is a “confined space” is made
proper pre-entry activities, as well as actual entry, and without regard to any hazards that may be present. In
ensures that the job is performed correctly and safely. fact, confined spaces do not necessardy present
The required skills and job duties include the following: hazards. Designation as a confined space in general
b Understanding the hazards that may be encoun- industry is based solely on the three criteria listed
tered during entry. above. The presence or absence of hazards determines
b Understanding how the materials being used and what type of confined space it is - permit-required
the work being performed may affect condltions or non-permit.
in the space as the job proceeds. However, all confined spaces have an inherent risk
b Knowing how to use the necessary safety equip- of such hazards. Confined spaces, by their nature,
ment and understanding its limitations. increase the likelihood of oxygen deficiency or accu-
b Knowing the signs and symptoms of exposure to mulation of toxic or flammable air contaminants. In
physical and chemical hazards present in the space. addition, other dangers may be present, including the
b Knowing what conditions are and are not permit- potential for entrapment, engulfment, or unexpected
ted in the space during entry. releases of energy (e.g., mechanical, electrical, pneu-
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matic) that can be disastrous to confined space person- Naturally, confined spaces in those types of areas may
nel. Finally, because of their typical configurations, contain flammable gas or vapors as well.
confined spaces often pose significant access problems. Class II locations are those areas where combus-
This can have a number of negative consequences, not tible dusts from such things as grain, flour, starch,
the least of which is increased difficulty of escape or wood, coal, and aluminum are present.
rescue should problems develop. As a result of these Class 111 locations are places where easily igmtable
and other hazards, confined spaces can indeed inca- fibers and flymgs are present but not likely to be in
pacitate, injure, or even kdl. suspension in sufficient quantity to produce an explo-
sive or ignitable mixture. Such locations would include
Enclosed space textde d s ,c lothing manufacturing plants, woodwork-
A term used in the electric power generation industry ing mills, etc.
Each of these three broad classes are further
and in shipyard employment to describe certain types
divided into “Division 1” and “Division 2,” which
of low-hazard confined spaces. It also appears in the
indicate the nature of the hazard (with Division 1
OSHA construction standard as another term for
representing, in general, a greater or more immediate
“confined space” (1926.21 @)(6)(ii)).
hazard). The Divisions within Classes I and I1 are
further divided into “Groups” of materials that pose
Entry
similar fwe and explosion hazards. (See 29 CRF
Occurs whenever any part of the body breaks the
1910.307 and 1910.399.)
plane of a confined space opening.
In addition, the phrases “entry” or “confined space
Hot work
entry” may also refer to on-going work in a confined
Activities such as welding, burning, cutting, grinding, or
space.
abrasive blasting that pose an igmtion hazard due to
sparks or hot surfaces. Such work may require a hot
Entry permit
work permit or a supervisor’s specific approval.
A document used by an employer to authorize and
control entry, and to control work that is performed in
Limited entry and exit
a permit space.
As a general rule, having to twist or contort the body
A permit is more likely to be used by employees if
or use hands in order to enter or exit a space, suggests
it makes their jobs easier, not harder. Consequently,
a lirmtation.
permits should be designed to be comprehensive,
Entry point size, shape, and height from the
logical, and easy to use. See examples in Appendix A.
worhng surface are important, but are not the only
considerations. Safe egress may also be restricted by 1)
Hazardous (c1assified)’locations
any obstructions within the space, or 2) the distance
These are defined by the National Electrical Code@
required to reach a safe zone.
(NEC) as areas with atmospheres that are subject to
h t e d e ntry or exit has implications for rescue
accumulations of flammable gases and vapors, or
purposes because of the additional time required for
combustible dusts, fibers, or flymgs. Their atmospheres
self-rescue or entry rescue.
are considered hazardous because they can easily be
igmted by various sources, including open flames, hot
Non-permit confined space
surfaces, and sparks given off by switches, motors, or
A confined space that does not contain or, with respect
relays. Hazardous locations are sometimes referred to
to atmospheric hazards, have the potential to contain
as “classified locations” because they are categorized
any hazard capable of causing death or serious physical
into three classes.
harm.
Class I locations are those where flammable gases
Examples include the areas above dropped
and vapors are or may be present in the air in sufficient
ceilings, vented vaults, and motor control cabinets.
quantity to create an explosive or ignitable mixture.
One must recope that the materials used and the
They typically include areas like flammable liquid
activities performed withm a non-permit space may
storage rooms, chemical plants, spray booths, automo-
create conditions that transform it into a permit-required
tive service stations, and LP gas handltng fachties.
5
space. For example, the use of an acutely toxic solvent, Properly reclassifying a permit-required space to
or certain types of weldmg inside a non-permit space non-permit status creates a win-win situation. By doing
would introduce the potential for atmospheric hazards so, the space is made much safer for the people who
and thus cause the space to become permit-required. d be entering, and the amount of regulatory compli-
Therefore, confined space entry teams must anticipate ance required for the job is greatly reduced.
not only the condltions that normally are present in a
space, but also hazards that may be caused by their Permit
work.
See “entry permit.”
Permit-required confined space
Permit system
A confined space that has one or more of the follow-
An organization’s written procedures for preparing and
ing characteristics:
issuing permits for entry, specifying designated work,
b Contains or has the potential to contain a hazard-
and returning the permit space to service following
ous atmosphere;
termination of entry.
b Contains a material that has the potential for
engulfing an entrant;
Program administrator
b Has an internal configuration such that an entrant
An individual designated to administer the confined
could be trapped or asphyxlated by inwardly
space program. This person must have technical
convergmg walls or by a floor that slopes down-
knowledge and effective understandmg of relevant
ward and tapers to a smaller cross-section; or
confined space entry standards, site operations, and the
b Contains any other serious safety or health hazard.
organization’s safety and health procedures for entering
permit-required confined spaces. (See Chapter 3.)
Examples of other serious safety or health hazards
include such things as moving equipment, extreme heat
Representatives paces
or cold, toxic chemical residue, rahation, and exposed
electrical sources. This could also include actlte biolog- Confined spaces having s d a rc haracteristics in terms
cal hazards such as snakes, animals, or microbials. Of:
Based on OSHA’s regulations for general industry, b Opening size and shape (e.g., oval and square
it is permissible to reclassi$ a permit-required con- openings of the same apparent size may actually
fined space to non-permit status under certain con&- dlffer significantly in the type of patient
tions. These are: “packagable” to be accommodated);
The space must not pose any actual or potential b Accessibhty (both to the opening, and then within
atmospheric hazards; the space, horizontally or vertically);
Any other hazards that may be present must be b Internal configuration (e.g., degree of congestion
ehnated prior to entry and must remain e h - inside the space); and
nated during entry; and b Hazards present.
A certification must be prepared and signed to
document the basis for determining that all This concept is important for rescue practices. (See
hazards have been eliminated. Chapter 7.)
Qualified person
NOTE: Simply controlling atmospheric hazards to Someone who, by possession of a recognized degree,
acceptable levels through ventdation Or other is certificate, or professional standmg, or who by exten-
not sufficient to allow reclassification. Any atmospheric sive howledge, training, and experience, has success-
hazards that do exist must be ehnated completely and
fully demonstrated the abhty to solve or resolve
there must be no reasonable potential for such hazards
problems relating to the subject matter, the or
to occur during entry. If atmospheric or other hazards the project,
do develop during entry, the employees must leave the
space immedately and the situation must be re-
evaluated to determine how it may be handled.
6
