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  • 1. Guidelines for Work in Inert Confined Spaces in the Petroleum Industry API PUBLICATION 2217A SECOND EDITION, SEPTEMBER 1997COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services, 2000
  • 2. One of the most signiÞcant long-term trends affecting the future vitality of the petro- leum industry is the publicÕs concerns about the environment. Recognizing this trend, API member companies have developed a positive, forward looking strategy called STEP: Strategies for TodayÕs Environmental Partnership. This program aims to address public concerns by improving industryÕs environmental, health and safety performance; docu- menting performance improvements; and communicating them to the public. The founda- tion of STEP is the API Environmental Mission and Guiding Environmental Principles. API standards, by promoting the use of sound engineering and operational practices, are an important means of implementing APIÕs STEP program. API ENVIRONMENTAL MISSION AND GUIDING ENVIRONMENTAL PRINCIPLES The members of the American Petroleum Institute are dedicated to continuous efforts to improve the compatibility of our operations with the environment while economically developing energy resources and supplying high quality products and services to consum- ers. The members recognize the importance of efÞciently meeting societyÕs needs and our responsibility to work with the public, the government, and others to develop and to use natural resources in an environmentally sound manner while protecting the health and safety of our employees and the public. To meet these responsibilities, API members pledge to manage our businesses according to these principles: q To recognize and to respond to community concerns about our raw materials, prod- ucts and operations. q To operate our plants and facilities, and to handle our raw materials and products in a manner that protects the environment, and the safety and health of our employees and the public. q To make safety, health and environmental considerations a priority in our planning, and our development of new products and processes. q To advise promptly appropriate ofÞcials, employees, customers and the public of information on signiÞcant industry-related safety, health and environmental hazards, and to recommend protective measures. q To counsel customers, transporters and others in the safe use, transportation and dis- posal of our raw materials, products and waste materials. q To economically develop and produce natural resources and to conserve those resources by using energy efÞciently. q To extend knowledge by conducting or supporting research on the safety, health and environmental effects of our raw materials, products, processes and waste materials. q To commit to reduce overall emissions and waste generation. q To work with others to resolve problems created by handling and disposal of hazard- ous substances from our operations. q To participate with government and others in creating responsible laws, regulations and standards to safeguard the community, workplace and environment. q To promote these principles and practices by sharing experiences and offering assis- tance to others who produce, handle, use, transport or dispose of similar raw materi- als, petroleum products and wastes.COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services, 2000
  • 3. Guidelines for Work in Inert Confined Spaces in the Petroleum Industry Health and Environmental Affairs Department Safety and Fire Protection Subcommittee API PUBLICATION 2217A SECOND EDITION, SEPTEMBER 1997COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services, 2000
  • 4. SPECIAL NOTES API publications necessarily address problems of a general nature. With respect to partic- ular circumstances, local, state, and federal laws and regulations should be reviewed. API is not undertaking to meet the duties of employers, manufacturers, or suppliers to warn and properly train and equip their employees, and others exposed, concerning health and safety risks and precautions, nor undertaking their obligations under local, state, or federal laws. Information concerning safety and health risks and proper precautions with respect to par- ticular materials and conditions should be obtained from the employer, the manufacturer or supplier of that material, or the material safety data sheet. Nothing contained in any API publication is to be construed as granting any right, by implication or otherwise, for the manufacture, sale, or use of any method, apparatus, or prod- uct covered by letters patent. Neither should anything contained in the publication be con- strued as insuring anyone against liability for infringement of letters patent. Generally, API standards are reviewed and revised, reafÞrmed, or withdrawn at least every Þve years. Sometimes a one-time extension of up to two years will be added to this review cycle. This publication will no longer be in effect Þve years after its publication date as an operative API standard or, where an extension has been granted, upon republication. Status of the publication can be ascertained from the API Authoring Department [telephone (202) 682-8000]. A catalog of API publications and materials is published annually and updated quarterly by API, 1220 L Street, N.W., Washington, D.C. 20005. This document was produced under API standardization procedures that ensure appropri- ate notiÞcation and participation in the developmental process and is designated as an API standard. Questions concerning the interpretation of the content of this standard or com- ments and questions concerning the procedures under which this standard was developed should be directed in writing to the director of the Authoring Department (shown on the title page of this document), American Petroleum Institute, 1220 L Street, N.W., Washington, D.C. 20005. Requests for permission to reproduce or translate all or any part of the material published herein should also be addressed to the director. API standards are published to facilitate the broad availability of proven, sound engineer- ing and operating practices. These standards are not intended to obviate the need for apply- ing sound engineering judgment regarding when and where these standards should be utilized. The formulation and publication of API standards is not intended in any way to inhibit anyone from using any other practices. Any manufacturer marking equipment or materials in conformance with the marking requirements of an API standard is solely responsible for complying with all the applicable requirements of that standard. API does not represent, warrant, or guarantee that such prod- ucts do in fact conform to the applicable API standard. All rights reserved. No part of this work may be reproduced, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording, or otherwise, without prior written permission from the publisher. Contact the Publisher, API Publishing Services, 1220 L Street, N.W., Washington, D.C. 20005. Copyright © 1997 American Petroleum InstituteCOPYRIGHT 2000 American Petroleum InstituteInformation Handling Services, 2000
  • 5. FOREWORD This publication provides guidelines to aid employers in preparing speciÞc procedures for the safe performance of work in inert conÞned spaces. API publications may be used by anyone desiring to do so. Every effort has been made by the Institute to assure the accuracy and reliability of the data contained in them; how- ever, the Institute makes no representation, warranty, or guarantee in connection with this publication and hereby expressly disclaims any liability or responsibility for loss or dam- age resulting from its use or for the violation of any federal, state, or municipal regulation with which this publication may conßict. Suggested revisions are invited and should be submitted to the Safety and Fire Protec- tion Subcommittee, American Petroleum Institute, 1220 L Street, N.W., Washington, D.C. 20005. iiiCOPYRIGHT 2000 American Petroleum InstituteInformation Handling Services, 2000
  • 6. COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services, 2000
  • 7. CONTENTS Page 1 SCOPE .............................................................................................................................. 1 2 REFERENCES.................................................................................................................. 1 3 DEFINITIONS.................................................................................................................. 1 4 ADMINISTRATIVE CONTROLS .................................................................................. 2 4.1 Written Procedures and Guidelines ......................................................................... 2 4.2 Entry Supervisor ...................................................................................................... 3 4.3 Contractors ............................................................................................................... 3 5 HAZARDS........................................................................................................................ 3 5.1 General ..................................................................................................................... 3 5.2 Oxygen DeÞciency .................................................................................................. 3 5.3 Fires and Explosions................................................................................................ 3 5.4 Pyrophoric Hazards.................................................................................................. 4 5.5 Physical Hazards...................................................................................................... 4 5.6 Toxic Substances...................................................................................................... 4 6 PRE-ENTRY CONSIDERATIONS ................................................................................. 5 6.1 General ..................................................................................................................... 5 6.2 Permits...................................................................................................................... 5 6.3 Inert Gas Source....................................................................................................... 6 6.4 Lockout/Tagout ........................................................................................................ 6 6.5 Ignition Sources ....................................................................................................... 6 6.6 Radiation Sources .................................................................................................... 6 6.7 On-Site Conditions................................................................................................... 6 6.8 Heat Stress................................................................................................................ 6 6.9 Testing and Monitoring............................................................................................ 6 7 PERSONAL PROTECTION ............................................................................................ 7 7.1 General ..................................................................................................................... 7 7.2 Respiratory Protection ............................................................................................. 7 7.3 Clothing.................................................................................................................... 7 7.4 Communications ...................................................................................................... 7 7.5 Attendant(s) Responsibilities................................................................................... 7 7.6 Entrant(s) Responsibilities....................................................................................... 8 7.7 Emergency Rescue Equipment................................................................................ 8 7.8 Rescue and Emergency Services ............................................................................. 8 8 OTHER CONSIDERATIONS.......................................................................................... 8 Figures 1 Flammability Limits .................................................................................................... 5 vCOPYRIGHT 2000 American Petroleum InstituteInformation Handling Services, 2000
  • 8. COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services, 2000
  • 9. Guidelines for Work in Inert Confined Spaces in the Petroleum Industry 1 Scope ANSI2 Z88.2 Practices for Respiratory Protection This publication provides guidelines for safely entering Z117.1 Safety Requirements for Working in Tanks and and working in and near conÞned spaces that have inert Other ConÞned Spaces atmospheres. This publication applies to conÞned spaces Z400.1 American National Standard for Hazardous that have been intentionally purged with an inert gas until Industrial ChemicalsÑMaterial Safety Data the vapor space and any emissions are below ßammable or SheetsÑPreparation reactive levels. This publication addresses special considerations for entry ASTM3 into conÞned spaces containing inert atmospheres and is D 4276 Practice for ConÞned Area Entry intended to supplement (not replace) the OSHA Permit- CGA4 Required ConÞned Spaces (29 Code of Federal Regulations G-7.1 Commodity SpeciÞcation for Breathing Air 1910.146) standard. Inert conÞned spaces are, by deÞnition, NFPA 5 always OSHA Permit-Required ConÞned Spaces and subject 69 Explosion Prevention Systems to the provisions of 29 Code of Federal Regulations 1910.146. 355M Fire Hazard Properties of Flammable Liquids, Inert atmospheres in conÞned spaces are hazardous atmo- Gases, Volatile Solids spheres that may expose entrants to the risk of death, incapac- OSHA6 itation, impairment of the ability to self-rescue (escape Occupational Safety and Health Standards (29 Code of unaided), injury, or acute illness. The fundamental concepts Federal Regulations Part 1910) presented here should be applicable to most situations that involve inert atmospheres in conÞned spaces in the petroleum 3 Definitions industry. The speciÞc work areas of concern are the inert con- Þned space itself and the area at or near the entrance to or For the purposes of this publication, the following deÞni- exhaust of the inerted space. tions apply. Other publications that provide information on work in 3.1 confined space: A space that: (a) is large enough conÞned spaces are listed in Section 2. Users of this guide and so conÞgured that an employee can bodily enter and per- should also refer to the applicable regulations and standards form assigned work; (b) has limited or restricted means for of federal, state, and local governments. entry or exit (for example, tanks, vessels, silos, storage bins, hoppers, vaults, and pits are spaces that may have limited 2 References means of entry); and (c) is not designed for continuous employee occupancy (see OSHA 29 Code of Federal Regu- The latest editions or revisions of the following publica- lations 1910.146). tions provide information supplementary to the text of this publication. 3.2 inert confined space: A conÞned space where the existing atmosphere is intentionally displaced with a non- API ßammable gas, such as nitrogen, creating an inert atmo- Publ 2013 Cleaning Mobile Tanks in Flammable or Com- sphere, in the conÞned space. An inert atmosphere is oxygen bustible Liquid Service deÞcient and immediately dangerous to life or health. Publ 2015 Safe Entry and Cleaning of Petroleum Storage Tanks 3.3 inert entry: The action by which a person passes Publ 2026 Guidelines for Safe Descent Onto Floating through an opening into a conÞned space having an inert Roofs of Tanks in Petroleum Service atmosphere. Such entry includes work activities in that Publ 2202 Dismantling and Disposing of Steel From space and is considered to have occurred as soon as any part Tanks Which Have Contained Leaded Gasoline 2 American National Standards Institute, 1430 Broadway, New York, New Publ 2207 Preparing Tank Bottoms for Hot Work York 10018. Publ 2221 ManagerÕs Guide to Implementing a Contrac- 3 American Society for Testing and Materials, 100 Bar Harbor Drive, West tor Safety and Health Program Conshohocken, Pennsylvania 19428. 4Compressed Gas Association, 1725 Jefferson Davis Highway, Arlington, ACGIH1 Virginia 22202. 5National Fire Protection Association, 1 Batterymarch Park, P.O. Box Threshold Limit Values for Chemical Substances and 9101, Quincy, Massachusetts 02269-9101. Physical Agents and Biological Exposure Indices. 6U.S. Occupational Safety and Health Administration, U.S. Department of Labor. The Code of Federal Regulations is available from the Superinten- 1 dent of Documents, U.S. Government Printing OfÞce, Washington, D.C. American Conference of Governmental Industrial Hygienists, Inc., 1330 Kemper Meadow Drive, Cincinnati, Ohio 45240-1634. 20402. 1COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services, 2000
  • 10. 2 API PUBLICATION 2217A of the entrantÕs body breaks the plane of an opening into the 3.9 upper flammable limit (UFL): Maximum concen- space. tration of a vapor in air (or other oxidant) above which propa- gation of ßame does not occur on contact with an ignition 3.4 oxygen-deficient atmosphere: Any atmosphere source. The upper ßammable limit is usually expressed as a containing less than 19.5 percent oxygen by volume. volume percentage of the vapor in air. [This deÞnition is 3.5 hazardous atmosphere: An atmosphere that may based on the deÞnitions of ßammable (explosive) limits given expose employees to the risk of death, incapacitation, impair- in NFPA 325M.] ment of ability to self-rescue (that is, escape unaided from a 3.10 pyrophoric: Designates a material that may sponta- permit space), injury, or acute illness from one or more of the neously ignite upon exposure to oxygen (air). following causes: a. Flammable gas, vapor, or mist in excess of 10 percent of 3.11 material safety data sheet (MSDS): Written or its lower ßammable limit (LFL). printed material concerning a hazardous chemical and pre- b. Airborne combustible dust at a concentration that meets or pared in accordance with OSHA 29 Code of Federal Regula- exceeds its LFL. tions Part 1910.1200. An MSDS provides data on physical properties, safety, Þre, and health for a particular chemical or Note: This concentration may be approximated as a condition in which the dust obscures vision at a distance of 5 feet (1.52 meters) or less. substance. c. Atmospheric oxygen concentration below 19.5 percent or 3.12 entry supervisor: The person (such as the above 23.5 percent. employer, foreman, or crew chief) responsible for deter- d. Atmospheric concentration of any substance for which a mining if acceptable entry conditions are present at a con- dose or a permissible exposure limit is published in [29 Code Þned space where entry is planned, for authorizing entry of Federal Regulations 1910.146] Subpart G, Occupational and overseeing entry operations, and for terminating Health and Environmental Control, or in Subpart Z, Toxic entry. and Hazardous Substances, of this part and which could Note: An entry supervisor also may serve as an attendant or as an authorized result in employee exposure in excess of its dose or permissi- entrant, as long as that person is trained and equipped as required by this sec- ble exposure limit. tion for each role he or she Þlls. Also, the duties of entry supervisor may be passed from one individual to another during the course of an entry opera- e. Any other atmospheric condition that is immediately dan- tion. (From 29 Code of Federal Regulations 1910.146.) gerous to life or health. Note: This deÞnition is from the OSHA Permit-Required ConÞned Space 4 Administrative Controls standard, 29 Code of Federal Regulations 1910.146. 4.1 WRITTEN PROCEDURES AND GUIDELINES 3.6 fit testing: The process of evaluating a respiratorÕs sealing characteristics for a speciÞc user and the respiratorÕs Each employer whose employees perform conÞned space performance for the user under controlled conditions. work in inert atmospheres shall establish and maintain writ- ten procedures and a system of authority and responsibility 3.7 immediately dangerous to life or health (IDLH): for controlling work in and near these conÞned spaces. As a Any condition that poses an immediate or delayed threat to minimum, the written procedures shall: life, or would cause irreversible adverse health effects, or interfere with an individualÕs ability to escape from a con- a. Be approved by facility management and identify who Þned space. will authorize inert conÞned space entry. b. Require that the entrants, entry supervisor, and rescuers be Note: Some materialÑnickel carbonyl, hydrogen ßuoride gas and cadmium vapor, for exampleÑmay produce immediate transient effects that, even if identiÞed. (See 4.2.) severe, may pass without medical attention, but are followed by sudden, pos- c. Provide for a written conÞned space entry permit. sibly fatal collapse 12Ð72 hours after exposure. The person Òfeels normalÓ d. Require all involved personnel to be trained in the hazards upon recovery from transient effects until collapse. Such materials in hazard- ous quantities are considered to be Òimmediately dangerous to life or health.Ó present in conÞned spaces with inert atmospheres. (From 29 Code of Federal Regulations 1910.146.) e. Require all involved personnel to be trained in the use of Note: Certain irritation effects may affect the ability to escape (see OSHA 29 proper equipment, procedures, and safeguards for their pro- Code of Federal Regulations 1910.146). tection. 3.8 lower flammable limit (LFL): The minimum con- f. Establish a procedure to ensure that training for all person- centration of a vapor in air (or other oxidant) below which nel is current before the start of each job. propagation of ßame does not occur on contact with an igni- g. Establish the requirements for a pre-job planning confer- tion source. The lower ßammable limit is usually expressed ence that involves representatives of those plant operations as a volume percentage of the vapor in air. [This deÞnition is affected by the entry to review the written procedures, super- based on the deÞnitions of ßammable (explosive) limits given visory responsibilities, work to be performed, potential haz- in NFPA 325M.] ards, and safeguards to be followed.COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services, 2000
  • 11. GUIDELINES FOR WORK IN INERT CONFINED SPACES IN THE PETROLEUM INDUSTRY 3 h. Establish appropriate emergency action plans (see 7.7 sibility, and (b) monitor the inert conÞned space work per- through 7.8). formed by contractors. i. Establish criteria to restrict access to the area in and near the conÞned space to prevent unauthorized entry into the con- 5 Hazards Þned space. 5.1 GENERAL 4.2 ENTRY SUPERVISOR To ensure the safety of personnel, the hazards of working in and near inert conÞned spaces must be recognized. Haz- Before entry begins, the entry supervisor identiÞed on the ards encountered in inert conÞned spaces may include but are permit shall sign the entry permit to authorize entry. not limited to the following: The employer must designate an entry supervisor to super- vise work that involves entering conÞned spaces with inert a. Oxygen deÞciency. atmospheres. See 1910.146 Item J, which requires the b. Fires and explosions. employer to ensure that each entry supervisor: c. Physical hazards. d. Toxic substances. a. Knows the hazards that may be faced during entry, includ- ing information on the mode, signs or symptoms, and conse- 5.2 OXYGEN DEFICIENCY quences of the exposure. b. VeriÞes by checking that the appropriate entries have been Oxygen deÞciency is the principal hazard to persons per- made on the permit, that all tests speciÞed by the permit have forming inert entry. The conÞned space to be entered is been conducted and that all procedures and equipment speci- purged with an inert gas to prevent Þre and explosion hazards Þed by the permit are in place before endorsing the permit and will have an oxygen-deÞcient atmosphere immediately and allowing entry to begin. dangerous to life or health. c. Terminates the entry and cancels the permit when: 1. The entry operations covered by the entry permit have 5.3 FIRES AND EXPLOSIONS been completed. The atmosphere within a conÞned space is rendered inert 2. A condition that is not allowed under the entry permit by reducing the oxygen content and thus eliminating possi- arises in or near the permit space. bility of Þres and explosions. The percentage of oxygen in d. VeriÞes that rescue services are available and that the the inert atmosphere is typically kept below 50 percent of means for summoning them are operable. the limiting oxygen concentration speciÞed in NFPA 69 (see e. Removes unauthorized individuals who enter or who NFPA 69, Table C-1). The procedure used to render the attempt to enter the permit space during entry operations. atmosphere inert should be continued at a rate sufÞcient to f. Determines, whenever responsibility for a permit space prevent oxygen from entering the space, as long as work is entry operation is transferred and at intervals dictated by conducted in the space. Purging may also be required to pre- the hazards and operations performed within the space, vent a spontaneous combustion of pyrophoric materials. that entry operations remain consistent with terms of the Contamination of the conÞned space with air may be caused entry permit and that acceptable entry conditions are main- by leaks into the space or the use of a contaminated purge tained. (From 29 Code of Federal Regulations 1910.146, gas. Prior to purging, check purge gas source and composi- Item J.) tion. The oxygen content of the conÞned space should be continuously monitored (see 6.9). Even though the mixture 4.3 CONTRACTORS inside the inert conÞned space is not ßammable (because of If a contractor is utilized to perform work in inert conÞned the reduced oxygen content), efßuent gas leaving the space spaces, the contractor shall certify to the owner/operator of from an open manway may mix with outside air and result the facility that the contractor conforms with the written pro- in a Þre and/or explosion hazard for personnel outside the cedures and guidelines speciÞed in 2.1 and other regulatory space. For many catalysts, an increase in carbon monoxide requirements. See API/CMA Recommended Practice 2221 and/or temperature may indicate oxygen intrusion causing for implementing a contractor safety and health program. spontaneous combustion of pyrophoric material. Whenever The owner/operator of the facility must advise contractors personnel are working near the point of entrance, steps of the potential hazards associated with the atmosphere being should be taken to assure the atmosphere at that point is not entered. The owner and the contractor must agree on any spe- a hazardous atmosphere, or that such personnel are properly cial precautions that are required. protected. The owner/operator of the facility shall establish the neces- CAUTION: Special monitoring equipment is typically sary procedures and system of authority to: (a) control the required to monitor ßammability limits accurately at reduced conditions of the inert conÞned space entry within its respon- oxygen levels. See manufacturerÕs speciÞcations for guidance.COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services, 2000
  • 12. 4 API PUBLICATION 2217A For a Þre or explosion to occur, there must be an adequate e. Unintentional operation of electrical or mechanical equip- amount of oxygen, the correct amount of vapors mixed with ment resulting from failure to properly isolate and lockout or the air, and an ignition source. For the Þre or explosion haz- tagout the equipment. ard to exist, the mixture of ßammable vapor(s) and air must f. Failure to isolate the space from potentially hazardous be within the ßammability limits for the particular vapors (see materials by blinding or disconnecting and blanking all lines Figure 1). Any mixture of vapor and air between the upper connected to the space (with the exception of the inert gas and lower ßammability limits will therefore ignite when purge line). exposed to an ignition source. g. Noise exceeding acceptable levels. The ßammability limits of many hydrocarbon vapors range h. Restrictive work space. from 1 to 10 percent vapor-to-air mixture; however, the ßam- i. Weather conditions such as lightning and high winds. mability limits of oxygenated materials (alcohol and glycols) j. Extreme temperatures that could cause physical stress to are much wider. entrant. Other classes of materials that can promote Þres are as fol- k. The use of communications or other equipment such as lows: video inspection equipment that is not intrinsically safe or not approved for service near the inert conÞned space. a. Pyrophoric materials. These are substances that ignite l. Cluttered or obstructed work space caused by poor house- spontaneously when they are exposed to air or oxygen (iron keeping. sulÞde, for example, which can be found on some vessel sur- m. Congestion at the job site caused by life-support hoses and faces and within certain regenerated catalysts). See 5.4 on breathing-air systems and the presence of standby attendants, pyrophoric hazards. rescue and emergency response equipment. b. Strong oxidizing substances. These are substances that n. The presence of radioactive materials or other radiation promote oxidation readily and may ignite on contact with sources. combustible material (for example, hydrogen peroxide, which o. Sharp or abrasive objects/surfaces on trays, lugs, brackets, is found in some waste treatment plants). and internal supports. c. Reactive substances. These are chemicals that undergo a p. The presence of standing water, increasing the risk of elec- self-accelerating exothermic reaction when a critical tem- trocution or slipping/falling. perature is reached. This reaction may produce rapidly expanding gases. 5.6 HAZARDOUS CHEMICALS 5.4 PYROPHORIC HAZARDS Hazardous chemicals can cause irritation, injury, immedi- During normal operations, certain catalysts often accumu- ate or delayed illness, or death depending upon the character- late pyrophoric deposits of iron and/or sulfur from the hydro- istics of the chemicals, the concentration, route of entry and carbons that pass through the catalyst bed. In some cases, duration of the exposure, and individual susceptibility. The when the catalyst is exposed to air, or another source of oxy- possible routes of exposure are inhalation, skin or eye absorp- gen, the pyrophoric deposits will begin to generate heat due tion, injection or ingestion, depending upon the characteris- to oxidation. If allowed to continue, this could generate a tics of the substance and the nature of the exposure. They can potential ignition source or hazardous emission. affect human tissue at the point of contact or at other body Inerting is one method used to reduce or minimize this parts remote from the point of contact. hazard. Irritants are substances that cause minor or transient but possibly painful injuries that heal without scars and produce 5.5 PHYSICAL HAZARDS no known after-effects. Many hydrocarbons and solvents are irritants; however, at higher exposure levels, hydrocarbons Physical hazards that may exist in inert conÞned spaces and solvents can cause central nervous system effects include the following: including dizziness, headaches, and confusion. Corrosives a. Structural failure; for example, the internal roof of a stor- are substances that destroy tissue and leave permanent scars. age tank may not support the worker(s) weight. Examples of corrosives are hydroßuoric acid, sulfuric acid, b. Catalyst beds inside a rector may pose particular hazards, and caustics. Acutely toxic substances are those that by a including: (1) the catalyst engulÞng workers, (2) the bed not single dose or short-term exposure may cause symptoms supporting their weight, or (3) the buildup of pressure under ranging from a simple headache or nausea to disablement or the catalyst bed causing the crust to rupture violently. death. c. InsufÞcient levels of illumination, improper lighting, A hazardous chemical that is somewhat unique to some glare, and shadows. conÞned spaces in reÞnery operations, such as reactor ves- d. A discharge of steam, high pressure air, water, hydrocar- sels using a nickel catalyst, is nickel carbonyl [Ni(CO)4] or bons, or chemicals into the conÞned space. nickel tetracarbonyl. Nickel carbonyl is a highly volatileCOPYRIGHT 2000 American Petroleum InstituteInformation Handling Services, 2000
  • 13. GUIDELINES FOR WORK IN INERT CONFINED SPACES IN THE PETROLEUM INDUSTRY 5 Percentage of flammable Total volume substance in total mixture of mixture Example of Flammable Rangesa of Some Common Substances 100% Too rich to burn LFL UFL Substance % % UFL Acetone 2.6 12.8 Flammable Carbon Disulfide 1.3 50.0 range Ethyl Alcohol 3.3 19.0 Ethyl Ether 1.9 36.0 LFL Gasoline 1.4 7.6 Too lean Jet Fuel (JP-4) 1.3 8.0 to burn Kerosene 0.7 5.0 a These ranges are only examples of mixtures in air at sea level. Flammability limits vary considerably with oxygen, pressure and substance present. Consult the MSDS or other material for the substance in question to confirm the exact LFL and UFL. Figure 1—Flammability Limits chemical that may be formed during the reaction of carbon item g). Entry into an inert conÞned space shall be considered monoxide with nickel. Due to nickel carbonylÕs highly volatile a Permit-Required ConÞned Space entry and subject to 29 characteristics, the route of exposure of concern is inhalation. Code of Federal Regulations 1910.146. Concentrations of only several parts per million (ppm) for short durations may cause severe acute symptoms; a concentration of 6.2 PERMITS 30 ppm for 30 minutes has been estimated to be lethal to A written permit to authorize inert entry shall include, but humans. The odor has been described as a Òdamp cellarÓ or is not limited to, the following elements listed under 29 Code ÒsootyÓ and is normally detected at about 1 to 3 ppm; it should of Federal Regulations 1910.146, Item f: be noted that the odor threshold is not low enough to provide adequate warning of potentially dangerous exposure to person- a. IdentiÞcation of the space to be entered and the work to be nel. There is often a delay in the onset of symptoms (dizziness, performed. headache, respiratory distress) of 12 to 36 hours after exposure. b. A drawing showing internal conÞguration, if it is not A determination should be made of the hazardous chemi- readily apparent to all involved. cal(s) in the conÞned space. Permissible exposure limits c. The date and duration of the permit. (PEL) as deÞned by OSHA and threshold limit values (TLV) d. The results of initial and periodic tests on oxygen as well as deÞned by ACGIH are terms commonly used to describe as ßammable and otherwise hazardous chemicals, including the airborne concentration of a substance below which, it is the name or initials of the testers and when the tests were per- believed, nearly all workers may be repeatedly exposed, day- formed. after-day, without adverse health effects. These terms are nor- e. IdentiÞcation of the personal protective equipment, testing mally expressed in ppm per volume of air or in milligrams of equipment, communications equipment, standing rescue substance per cubic meter of air (mg/m3). The MSDSs pro- equipment, and alarm systems required. vide information such as potential effects of overexposure, f. Any additional information or other requirements for the permissible exposure levels, and personal protective informa- job to be performed safely (e.g., low voltage lightning, con- tion about toxic substances, and should be obtained from the tinuous monitoring of oxygen and LFL). employer, manufacturer, or supplier of the substance. A deter- g. The names of authorized entrants within the space. mination should also be made regarding the personal protec- h. The names of attendants. tive equipment required (see Section 7) and administrative i. IdentiÞcation of the hazards in the space, at the point of controls (see Section 4) should be established to safeguard entry, and at the emission point. personnel in the immediate work area. Testing and monitoring j. IdentiÞcation of measures used to isolate the space, and to requirements for toxic substances are covered in 6.9. control the hazards in the space before entry. k. SpeciÞcation of acceptable entry conditions. 6 Pre-Entry Considerations l. IdentiÞcation of rescue and emergency services and the means for summoning those services. 6.1 GENERAL m. IdentiÞcation of communications procedures used by The safeguards prescribed in 6.2 through 6.9 should be authorized entrants and attendants to maintain contact dur- addressed as part of the pre-job planning conference (see 4.1, ing entry.COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services, 2000
  • 14. 6 API PUBLICATION 2217A n. IdentiÞcation of the person, by name, currently serving as 6.7 ON-SITE CONDITIONS entry supervisor. A qualiÞed person or persons should ensure that the fol- o. IdentiÞcation of the entry supervisor who originally autho- lowing are provided as appropriate: rized the entry (by name or initial). p. IdentiÞcation of any additional permits (e.g., hot work) a. Fire equipment, such as Þre extinguishers or charged Þre issued to authorize work in the inert space. water hose lines. Personnel should be knowledgeable in their proper use. The written permit must be signed by the issuer and the b. Adequate illumination. If artiÞcial illumination is required recipient of the permit. All permits must be maintained for at it should consist of equipment suitable for use in ßammable least one year following the completion of the work, as atmospheres. required by 29 Code of Federal Regulations 1910.146. c. Pneumatic tools powered with nitrogen to prevent the 6.3 INERT GAS SOURCE introduction of air into the inert atmosphere. d. Protection from electrical shock provided by ground fault The source of the inerting gas should be veriÞed to ensure circuit interruption (GFCI) or a 12-volt system if the conÞned that the inert atmosphere will be maintained. The following space is damp or wet. elements should be checked: e. Demarcation around an areaÕs open manway beyond a. The composition of the gas will adequately inert the atmo- which personnel cannot enter without proper respiratory pro- sphere. tection equipment. b. There is an adequate supply of the gas, including a contin- f. Posted Permit-Required ConÞned Space signs. gency supply. g. Ventilation if necessary. If an enclosure or partial enclo- c. There is an adequate ßow of inert gas into the conÞned sure is built over the point of entrance to protect personnel space to maintain an inert atmosphere. from weather, care must be taken to ensure the purge gases do d. The internal pressure of the inert conÞned space is not not accumulate. This may require ventilation to allow ade- being built up by the inerting gas. quate dilution, or cessation of work until the enclosure is no longer needed. The source and inert-space atmosphere should be continu- h. Careful coordination and review of work planned near the ously monitored. Any loss in control must result in immedi- inert space, especially near the entrance point, for incompati- ate evacuation of entrants (see 6.9). bility with possible rescue operations. 6.4 LOCKOUT/TAGOUT (ISOLATION) 6.8 HEAT STRESS The conÞned space must be isolated from sources of poten- tially hazardous energy and materials. All energy sources con- In general, the higher the temperature and humidity within nected to the conÞned space shall be locked and/or tagged out the conÞned space and the more strenuous the work load, the to prevent injuries to personnel or damage to equipment that greater the heat stress. For further information, refer to the might occur if the equipment were inadvertently activated. most recent edition of the ACGIH TLV Handbook to deter- Also, all vessels shall be isolated from all sources of hazard- mine the permissible heat exposure threshold limit value that ous materials by blinding or disconnecting and blanking all will apply to a given work environment. lines connected to the space (with the exception of the purge If it appears heat stress is a potential problem, temperatures gas line). See OSHA Lockout/Tagout regulatory requirements inside the conÞned space should be checked initially and then under 29 Code of Federal Regulations 1910.147. continuously monitored. If temperature indicators have been disconnected or do not function properly, an alternative 6.5 IGNITION SOURCES method of measuring temperature must be considered (e.g., a temperature gauge lowered via a hand line into the conÞned All activities that could provide an ignition source such as space work area). smoking, welding, grinding, and internal combustion engines Work/rest cycles and/or entry durations should be adjusted should be identiÞed and removed or controlled to prevent the as needed to prevent heat-related problems among entrants. ignition of ßammable or combustible materials. When hot work is required, appropriate precautions should be taken. 6.9 TESTING AND MONITORING Materials used for tents/enclosures should be of Þre-resistant composition and construction. The atmosphere in the inert conÞned space shall be tested to determine if entry is permissible. The oxygen content of 6.6 RADIATION SOURCES the conÞned space and the efßuent must be monitored con- Radiation sources, if present, should be removed or tinuously while work in the conÞned space is in progress. shielded and locked in accordance with instructions from the The following additional criteria should be considered for siteÕs radiation safety ofÞcer. monitoring:COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services, 2000
  • 15. GUIDELINES FOR WORK IN INERT CONFINED SPACES IN THE PETROLEUM INDUSTRY 7 Acceptable for Inert Entry g. A quality assurance program should be established to con- Þrm the quality of the compressed breathing air (suggested Oxygen <5% veriÞcation regimen is provided in ANSI Z88.2). Flammable <10% LFL h. If a compressor is used, it shall be located to prevent entry Temperature See 6.8. Follow accepted work rates of contaminated air into the air-supply system. Oil lubricated based on temperature and compressors must be equipped with a carbon monoxide alarm. humidity (i.e., heat index). i. Breathing-air couplings should be incompatible with out- lets for nonrespirable plant air or other gas systems to prevent CAUTION: Special monitoring equipment is typically the inadvertent cross connection of air-line respirators with required to monitor ßammability limits accurately at oxygen nonrespirable gases. levels below 10 percent O2. j. Two independent sources of air shall be provided for each person working in an inert conÞned space. A third source of Where temperature indicators and recorders are used, they air may also be appropriate when complicated internals or should remain in service during the entry and purging opera- limited access to the work area are present that may hinder tions. The area around the opening should also be monitored, emergency egress from the conÞned space. particularly if there is an enclosure or partial enclosure k. A trained person must continually monitor the air supply Equipment used to analyze the conÞned space atmosphere of the workers in and near the conÞned space. conditions must be properly calibrated to ensure accurate l. An emergency alarm, either audible or visible, should be readings for oxygen and lower ßammability limit (LFL). used to indicate a reduction in breathing-air supply or pres- sure. All personnel should evacuate the conÞned space when 7 Personal Protection the emergency alarm is activated. 7.1 GENERAL m. All persons wearing respirators shall be trained in the Each employee involved with entry and work in and near proper Þt and use of the equipment selected for use in the inert conÞned spaces must understand the hazards involved inert atmosphere. (see Section 5). Evaluation of these hazards will determine The OSHA Standards for Respiratory Protection, 29 Code the selection and use of personal protective equipment and of Federal Regulations 1910.134, provides speciÞc require- training requirements. This section provides guidance in ments for the proper Þt testing, selection, use, and mainte- determining the proper personal protection. nance of respirators and required medical surveillance. 7.2 RESPIRATORY PROTECTION 7.3 CLOTHING The following measures should be evaluated and imple- Appropriate clothing must be worn to provide protection mented as necessary by a qualiÞed person: from the hazards identiÞed during the pre-job planning. Arti- a. Person(s) required to enter the inert conÞned space shall cles of clothing must provide protection against any harmful wear at least a positive-pressure, full-facepiece, air-line respi- substances and/or conditions present in or near the inert con- rator with an auxiliary self-contained escape air supply of suf- Þned space. Þcient capacity to allow emergency escape. b. Personnel required to be in the area of point of entrance 7.4 COMMUNICATIONS shall wear at least a positive-pressure, full-facepiece, air-line A reliable and effective communication system is neces- respirator if any part of their body may break the plane of the sary to link those within the inert conÞned space to the atten- vessel of entry, or if they may reasonably be exposed to a haz- dant(s) and/or others on the outside. If communication is ardous atmosphere. interrupted, personnel should be evacuated from the conÞned c. The helmet, hood, or suit should be sufÞciently secure to space and should not return until a reliable communication prevent inadvertent removal. link can be assured. The communication system must be d. When persons are in an inert conÞned space, at least one rated as intrinsically safe. attendant must be readily available outside the point of egress for the purpose of communications and to initiate emergency 7.5 ATTENDANT(S) RESPONSIBILITIES response. Attendant(s) are required while work is being performed in e. Breathing air may be supplied to respirators from cylin- an inert conÞned space. Attendant(s) shall have no other ders or suitable air compressors. duties and should be appropriately trained and thoroughly f. Compressed breathing air should at least meet the require- familiar with the following: ments of the speciÞcation for Type I, Grade D, breathing air as described in the latest edition of CGA G-7.1, Commodity a. Effective use of communications systems. SpeciÞcation for Breathing Air. b. Respiratory protection equipment being used.COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services, 2000
  • 16. 8 API PUBLICATION 2217A c. Emergency rescue equipment, if the attendant is responsi- the work site. This equipment includes, but may not be lim- ble for initiating rescue. ited to the following: d. Emergency Þrst aid, cardiopulmonary resuscitation a. Hoisting device to extricate personnel from the conÞned (CPR), and bloodborne pathogens (OSHA 29 Code of Fed- space. eral Regulations 1910.1030), if the attendant will be per- b. Extra supplied air breathing equipment for entry during forming as a rescuer. rescue. e. Emergency notiÞcation procedures and when to use them. c. Extra protective clothing for entry during rescue. f. Inert conÞned space entry procedures that are applicable d. Additional ropes and harnesses. to his or her duties. e. First-aid kit. g. Housekeeping requirements at entry point. f. Fire extinguishers. h. ConÞned space physical and/or health hazards, including g. Basket stretchers. possible behavioral effects of hazards on entrants. h. A means of lowering injured persons to the ground. i. Requirement to ensure entry personnel are properly i. Rescue tools, including jacks, pry bars, a cutting torch, a equipped with appropriate personal protective equipment and chain fall. respiratory protection before entering conÞned space. j. Provisions for summoning assistance. j. How to identify and maintain an accurate count of autho- rized entrants. 7.8 RESCUE AND EMERGENCY SERVICES k. Requirement to remain outside of permitted space during entry operations until properly relieved by another attendant. Before entry into an inert conÞned space is authorized, l. The types of unsafe conditions, situations or behaviors provisions must be made for addressing medical emergencies inside or outside the space which should cause the attendant that may arise during the work. See 1910.146, Item k for to order an evacuation. requirements. m. Needs and procedures to warn and deny unauthorized Personnel trained in cardiopulmonary resuscitation, Þrst access to the permit space and to the adjacent work area. aid (including burns), and the use of appropriate rescue equipment (see 7.7) must be available during all work in the 7.6 ENTRANT(S) RESPONSIBILITIES inert conÞned space. Provisions must include timely access to professional med- Entrant(s) working in an inert conÞned space should be ical treatment. Planning should recognize and emphasize the appropriately trained and thoroughly familiar with the fol- nature of hazards that are immediately dangerous to life and lowing: health and the very limited time available for successful res- a. Effective use of communications systems. cue and treatment. b. Respiratory protection equipment being used. c. Emergency rescue equipment. 8 Other Considerations d. Emergency notiÞcation and evaluation procedures. Work in an inert conÞned space presents many unique haz- e. Inert conÞned space entry procedures. ards that may not be encountered in a typical conÞned space f. Hazards that may be encountered during entry. entry. The performance of such work and the special precau- g. Proper use of equipment to be used while working in an tions and equipment necessary are commonly obtained via inert conÞned space. specialized contractors. Inert conÞned space entries do not h. Procedures for communication with attendant to monitor occur frequently in the petroleum industry and the decision to entrant status. perform this work activity must be carefully reviewed and i. Safe work practices while working in an inert conÞned approved by the facility/location management before such space. work takes place. 7.7 EMERGENCY RESCUE EQUIPMENT The equipment necessary for rescuing personnel working in an inert conÞned space shall be immediately available atCOPYRIGHT 2000 American Petroleum InstituteInformation Handling Services, 2000
  • 17. API Related Publications Order Form t API Member (Check if Yes) Date: (Month, Day, Year) Invoice To – t Check here if same as “Ship To” Ship To – (UPS will not deliver to a P.O. Box) Company Company Name/Dept. Name/Dept. Address Address City State/Province City State/Province Zip Country Zip Country Customer Daytime Telephone No. Customer Daytime Telephone No. Fax No. Fax No. (Essential for Foreign Orders) (Essential for Foreign Orders) PREPAID AND CREDIT CARD ORDERS ARE NOT CHARGED FOR SHIPPING AND HANDLING TO U.S. AND CANADIAN DESTINATIONS t Payment Enclosed $ t Please Bill Me P.O. No. t Payment By Charge Account: t MasterCard t Visa t American Express Customer Account No. Account No. State Sales Tax – The American Petroleum Institute is required to collect sales tax on publications mailed to the following states: AL, AR, CT, DC, FL, GA, IL, IN, IA, KS, KY, ME, MD, MA, MI, MN, MO, NE, NJ, NY, Name (As it appears on Card) NC, ND, OH, PA, RI, SC, TN, TX, VT, VA, WV, and WI. Prepayment of orders shipped to these states should include applicable sales tax unless a purchaser is exempt. If exempt, please print your state exemption number and Expiration Date enclose a copy of the current exemption certificate. Exemption Number State Signature Quantity Order No. Title Unit Price Total K20260 Publ 2026, Safe Descent Onto Floating Roofs of Tanks in Petroleum Service $ 30.00 Std 2015, Safe Entry and Cleaning of Petroleum Storage Tanks, Planning and Managing K20155 $ 70.00 Tank Entry from Decommissioning Through Recommissioning K23502 RP 2350, Overfill Protection for Storage Tanks in Petroleum Facilities $ 40.00 Shipping and Handling – All orders are shipped via UPS or First Class Mail in the U.S. and Canada. Subtotal Orders to all other countries will be sent by Airmail. State Sales Tax (see above) Rush Shipping Charge – Federal Express, $10 in addition to customer providing Federal Express account number: ________________________. UPS Next Day, $10 plus the actual shipping costs (1-9 Rush Shipping Charge (see left) items). UPS Second Day, add $10 plus the actual shipping costs (1-9 items). Rush Bulk Orders – 1-9 items, $10. Over 9 items, add $1 each for every additional item. NOTE: Shipping Shipping and Handling (see left) on foreign orders cannot be rushed without Federal Express account number. Total (in U.S. Dollars) Bill and Ship Orders – U.S. and Canada, $4 per order handling fee, plus actual shipping costs. All other Pricing and availability countries, for Airmail (standard service) add 25% of order value. All other countries, for UPS Next Day, add an subject to change additional 10% of order value. without notice. Mail Orders: American Petroleum Institute, Order Desk, 1220 L Street, N.W., Washington, DC 20005-4070 Fax Orders: (202) 962-4776 Phone Orders: (202) 682-8375 To better serve you, please refer to this code when ordering: K S 3 2 3 2 0 9 9 7COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services, 2000
  • 18. The American Petroleum Institute provides additional resources and programs to industry which are based on API Standards. For more information, contact: • Training and Seminars Ph: 202-682-8490 Fax: 202-682-8222 • Inspector Certification Programs Ph: 202-682-8161 Fax: 202-962-4739 • American Petroleum Institute Ph: 202-962-4791 Quality Registrar Fax: 202-682-8070 • Monogram Licensing Program Ph: 202-962-4791 Fax: 202-682-8070 • Engine Oil Licensing and Ph: 202-682-8233 Certification System Fax: 202-962-4739 • Petroleum Test Laboratory Ph: 202-682-8064 Accreditation Program Fax: 202-962-4739 In addition, petroleum industry technical, patent, and business information is available online through API EnCompass™. Call 212-366-4040 or fax 212-366-4298 to discover more. To obtain a free copy of the API Publications, Programs, and Services Catalog, call 202-682-8375 or fax your request to 202-962-4776. Or see the online interactive version of the catalog on our World Wide Web site – http://www.api.org.COPYRIGHT 2000 American Petroleum InstituteInformation Handling Services, 2000
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  • 20. Additional copies available from API Publications and Distribution: (202) 682-8375 Information about API Publications, Programs and Services is available on the World Wide Web at: http://www.api.org Order No. K2217ACOPYRIGHT 2000 American Petroleum InstituteInformation Handling Services, 2000