1、BY THE ANSI/AIHA Z9.7 SubcommitteeA Publication by American Industrial Hygiene AssociationRecirculationof Air from IndustrialProcess Exhaust SystemsANSI/AIHA Z9.72007Copyright AIHA For personal use only. Do not distribute.Please note the American Society of Safety Engineers (ASSE) is now the Secreta
2、riat of the Z9 ASC and holds the copyright to this standard.American Society of Safety Engineerswww.asse.orgASSECopyright AIHA For personal use only. Do not distribute.ANSI/AIHA Z9.72007American National Standard for the Recirculation of Air from Industrial Process Exhaust SystemsSecretariatAmerican
3、 Industrial Hygiene AssociationApproved: January 16, 2007American National Standards Institute, IncCopyright AIHA For personal use only. Do not distribute.Please note the American Society of Safety Engineers (ASSE) is now the Secretariat of the Z9 ASC and holds the copyright to this standard.America
4、n Society of Safety Engineerswww.asse.orgAmericanNationalStandardApproval of an American National Standard requires verification by ANSI thatthe requirement for due process, consensus, and other criteria for approvalhave been met by the standards developer.Consensus is established when, in the judgm
5、ent of the ANSI Board ofStandards Review, substantial agreement has been reached by directly andmaterially affected interests. Substantial agreement means much more than asimple majority, but not necessarily unanimity. Consensus requires that allviews and objection be considered, and that a concerte
6、d effort be madetoward their resolution.The use of American National Standards is completely voluntary. Their exis-tence does not in any respect preclude anyone, whether he or she hasapproved the Standards, or not, from manufacturing, marketing, purchasing, orusing products, processors, or procedure
7、s not conforming to the Standards.The American National Standards Institute does not develop standards andwill in no circumstances give an interpretation of any American NationalStandard. Moreover, no person shall have the right or authority to issue aninterpretation of an American National Standard
8、 in the name of the AmericanNational Standards Institute. Requests for interpretations should be addressedto the secretariat or sponsor whose name appears on the title page of thisstandard.CAUTION NOTICE: This American National Standard may be revised or with-drawn at any time. The procedures of the
9、 American National StandardsInstitute require that action be taken to reaffirm, revise, or withdraw thisStandard no later than five years from the date of approval. Purchasers ofAmerican National Standards may receive current information on all standardsby calling or writing the American National St
10、andards Institute.Published byAmerican Industrial Hygiene Association2700 Prosperity Ave., Suite 250Fairfax, VA 22031www.aiha.orgCopyright 2007 by the American Industrial Hygiene AssociationAll rights reserved.No part of this publication may be reproduced in any form, in an electronic retrieval syst
11、em or otherwise, without the prior written permission of the publisher.Printed in the United States of America.Stock No: IVEA07-721ISBN-13: 978-1-931504-79-9Copyright AIHA For personal use only. Do not distribute.ContentsPage Foreword .iiiSubcommittee Members.iv1. Scope, Purpose, and Application 11.
12、1 Scope.11.2 Purpose .11.3 Application .11.4 Exclusions12. Referenced Standards and Publications .12.1 General 12.2 American National Standards22.3 Occupational Safety and Health Administration Standards.22.4 Related Standards .23. Definitions and Units .23.1 Acceptable Level23.2 Air Cleaning Equipm
13、ent.33.3 Back-Up Filter 33.4 Carcinogen.33.5 Contaminant.33.6 Continuous Monitoring Device (CMD) .33.7 Dusts33.8 Exhaust Air 33.9 Exhaust Rates .33.10 Exhaust System.33.11 Fume33.12 Gas 33.13 High Efficiency Particulate Air (HEPA) filter.33.14 Highly Toxic Materials 43.15 Industrial Process 43.16 Ma
14、ke-up Air43.17 Recirculating Exhaust System.43.18 Recirculation 43.19 Redundant Filter (back-up filter) 43.20 Replacement Air 43.21 Supply Air 43.22 Threshold Limit Value (TLV).43.23 Units and Abbreviations.43.24 Vapor43.25 Mist or Fog.53.26 Smoke5Copyright AIHA For personal use only. Do not distrib
15、ute.4. General Process Exhaust System Design 54.1 System Configuration 54.2 Hazard Evaluation and Analysis54.2.1 Material Requiring Special Precautions.54.3 System Discharging.65. Air Cleaning Equipment.65.1 Multiple Contaminants.66. Continuous Monitoring Device System Monitor.67. Maintenance .78. R
16、ecord Keeping .79. Signs .7Copyright AIHA For personal use only. Do not distribute.FOREWORD (This foreword is not part of ANSI/AIHA Z9.7-2007)Operation of modern industrial facilities calls for increasing efficiency and conservation.Recirculation of general ventilation has become a mainstay of energ
17、y conservation, but recircula-tion of air from industrial process exhaust systems must be carefully considered. The potential forreturn of toxic contaminants to the facility through recirculation of industrial process air requiresthat this process be thoroughly analyzed and well-designed. The Z9.7 s
18、ubcommittee was chartered to develop guidelines on this specific aspect of industrialventilation. The following Z9.7 American National Standard is the product of this subcommitteesefforts. It provides guidance on issues to consider whenever industrial process air is recirculated.However, it is not i
19、ntended to apply to recirculation of building or room air through general HVACsystems. This standard is not meant to be all-encompassing. Rather, it establishes minimal acceptable crite-ria for analysis and evaluation of the appropriateness of recirculation of industrial process air, andminimum requ
20、irements to assure the safety of affected workers. It is somewhat general in nature.We hope, however, that future versions will continue to expand and amplify these concepts asadditional experience is gained. Suggestions for improvement of this standard are welcome. Theyshould be sent to the America
21、n Industrial Hygiene Association, 2700 Prosperity Avenue, Suite 250,Fairfax, VA 22031. This standard was processed and approved for submittal to ANSI by the Z9 Accredited StandardsCommittee on Health and Safety Standards for Ventilation Systems. Committee approval of theStandard does not necessarily
22、 imply that all committee members voted for its approval. At the timeit approved this Standard the Z9 Committee had the following members:L. DiBerardinis, CIH, CSP, ChairJ. M. Price, CIH, CSP, PE, Vice ChairMili Mavely, Secretariat RepresentativeOrganization Represented Name of RepresentativeAllianc
23、e of American Insurers S. EcoffAmerican Chemical Society D. WaltersAmerican Conference of Governmental Industrial Hygienists G. KnutsonAmerican Automobile Manufacturers Association G.M. AdamsAmerican Foundrymens Society R. ScholzAmerican Glovebox Society S. CrooksAmerican Society of Heating, Refrige
24、rating, and Air Conditioning Engineers H.F. BehlsChemical Industry Institute of Toxicology J.L. CookMassachusetts Institute of Technology L.J. DiBerardinis National Association of Metal Finishers K.C. HankinsonNational Spray Equipment Manufacturers Association D.R. ScarboroughNational Institute of O
25、ccupational Safety and Health J.W. SheehyU. S. Department of Labor Occupational Safety and Health Administration I. WainlessIndividual MembersD. BlackburnD.J. BurtonC. FigueroaS.J. GunselR.L. KarbowskiN. McManusD. OBrieniiiANSI/AIHA Z9.72007K. PaulsonJ.M. PriceJ.C. RockM. RollinsT.C. SmithL.K. Turne
26、rCopyright AIHA For personal use only. Do not distribute.ivANSI/AIHA Z9.72007The Z9.7 subcommittee on Recirculation of Air from Industrial Process Exhaust Systems, whichdeveloped this standard, had the following members:G.M. Adams, ChairL. DiBerardinisD. OBrienK. PaulsonM. RollinsI. WainlessCopyrigh
27、t AIHA For personal use only. Do not distribute.1. Scope, Purpose, and Application1.1 ScopeThis standard established minimum crite-ria for the design and operation of arecirculating industrial process exhaustventilation system used for contaminantcontrol.1.2 PurposeThe purpose of this standard is to
28、 estab-lish minimum guidelines to determine: If the air from an industrial processcan be passed through an air clean-ing device and safely recirculatedwithin the building; Appropriate methods and equipmentare being used to identify the con-taminants generated by an industrialprocess during normal an
29、d upsetconditions; and Possible health and safety problemsthat shall be addressed if recircula-tion is to be used.1.3 ApplicationIn order to provide a safe and comfort-able work environment and reduce theenergy required to make up the airexhausted from the building, the contami-nated air from proces
30、s exhaust systemscan be cleaned and kept within the build-ing, thereby reducing the amount of addi-tional outside, or make-up air needed.The recirculation of exhaust air from anindustrial process is a potentially danger-ous practice. If done improperly, harmfulconcentrations of air contaminants canb
31、e created in the work environment. Allaspects of the process, all possible combinations of the base materials, andthe materials that can be created duringthe process shall be researched anddocumented before recirculation is con-sidered.The facility owner and manager bothmust understand that a recirc
32、ulatingprocess exhaust system requires a high-er level of preventive maintenance,including system and component testing,than a conventional process exhaust sys-tem for the life of the system.This standard outlines the minimum crite-ria that shall be considered in designinga recirculating industrial
33、process exhaustsystem.1.4 ExclusionsThis standard does not apply to the recir-culation of building or room air throughgeneral HVAC systems. It also does notapply to general building exhaust unitssuch as propeller fan roof ventilators.2. Referenced Standards andPublications2.1 GeneralThe regulations,
34、 standards, and guide-lines cited in 2.2, 2.3, and 2.4 containprovisions which, through reference inthis text, constitute provisions of thisAmerican National Standard. The relatedstandards cited in 2.5 contain additionalinformation but are not essential for com-pleting the requirements of this stand
35、ard.At this time of publication, the editionsindicated were current. All standards andguidelines are subject to revision, and1American National Standard for the Recirculation of Air from Industrial ProcessExhaust SystemsAMERICAN NATIONAL STANDARD ANSI Z9.72007Copyright AIHA For personal use only. Do
36、 not distribute.users of this American National Standardare encouraged to consult the mostrecent editions of the standards andguidelines indicated below.2.2 American National StandardsANSI Z9.2-2001, FundamentalsGoverning the Design and Operation ofLocal Exhaust Systems(1)2.3 Occupational Safety and
37、 HealthAdministration StandardsCode of Federal Regulations, title 29,Part 1910, Section 1200, “HazardCommunication.”(2)2.4 Other PublicationsIndustrial Ventilation A Manual ofRecommended Practice, 25thEdition.Cincinnati, Ohio: American Conference ofGovernmental Industrial Hygienists,1998.(3)Threshol
38、d Limit Values for ChemicalSubstances and Physical Agents andBiological Exposure Indices. Cincinnati,Ohio: American Conference ofGovernmental Industrial Hygienists.Published annually.(3)“Air Cleaning” (Chapter 29). In FanEngineering, 9th Edition, HowdenBuffalo, Inc.(4)“Gas Stream Sampling” (Chapter
39、22). InAir Sampling Instruments, 9th Edition.Cincinnati, Ohio: American Conference ofGovernmental Industrial Hygienists,20015.(3)NFPA 664-2000, Prevention of Fires andExplosions in Wood Processing andWoodworking Facilities NFPA 68-2002, Venting ofDeflagrations(5)NFPA 69-2002, Explosion PreventionSys
40、tems(5)2.4 Related StandardsANSI/AIHA Z9.3-1994, Spray FinishingOperations Safety Code for Design,Construction, and Ventilation(1)ANSI/ASHRAE 62.1-2004, Ventilation forAcceptable Indoor Air Quality plusaddenda ANSI/NFPA 33-1995, Spray ApplicationUsing Flammable and CombustibleMaterials(5)Code of Fed
41、eral Regulations, Title 29,Part 1910, Section 94, “Ventilation.”(2)Code of Federal Regulations, Title 29,Part 1910, Section 107, “Spray FinishingUsing Flammable and CombustibleMaterials.”(2)Code of Federal Regulations, Title 29,Part 1910, Subpart Z, “Toxic andHazardous Substances.”(2)3. Definitions
42、and UnitsThe following are terms and definitionsused in this document.3.1 Acceptable LevelA concentration of contaminant in air inthe workplace less than the levelsallowed by the official agency havingjurisdiction. In the absence of legallymandated levels other standards orguidelines should be used.
43、2ANSI/AIHA Z9.72007(1) Available from the AIHA, 2700 Prosperity Ave., Suite 250, Fairfax, VA 22031(2) Available from the U.S. Government Printing Office, Washington, DC 20402-9325(3) Available from the American Conference of Governmental Industrial Hygienists, Kemper Wood Center, 1330 Kemper Meadows
44、 Drive, Cincinnati, OH 45240(4) Available from Howden Buffalo, Inc., 2029 W. DeKalb St., Camden, SC 29020, or by calling (803) 713-2200.(5) Available from the National Fire Protection Association, 1 Batterymarch Park, Quincy, MA 02269(6) Available from the American Society of Heating, Refrigerating
45、and Air-Conditioning Engineers, Inc., 1791 Tullie Circle, N.E., Atlanta GA 30329Copyright AIHA For personal use only. Do not distribute.If these sources do not provide informa-tion on the chemicals used in the process,the owner-operator should, with the assis-tance (if necessary) of a qualified indu
46、stri-al hygienist or industrial toxicologist,establish comparable in-house standardsbased on the best available information.3.2 Air Cleaning EquipmentA device or combination of devices forremoving contaminants from the air han-dled by an exhaust system.3.3 Back-Up FilterSee 3.19 (redundant filter).3
47、.4 CarcinogenA substance meeting either of the follow-ing criteria: The definition of “carcinogen” asfound in the OSHA HazardCommunication standard, 29 CFR1910.1200, Appendix A, paragraph(1) or Any of the definitions of A1-“Confirmed Human Carcinogen,” A2-“Suspected Human Carcinogen,” orA3-“Animal C
48、arcinogen” in AppendixA of the most current edition of theACGIH TLV and BEI booklet. 3.5 ContaminantAn unwanted airborne constituent thatmay reduce the acceptability of the air.3.6 Continuous Monitoring Device (CMD)An air sampling instrument, usually fixedin one location, designed to continuouslyor
49、repeatedly sample the air for a specificcontaminant. CMDs usually produce acontinuous display of results and areoften designed to trigger an audibleand/or visual warning device in the eventcontaminant levels exceed a predeter-mined amount.3.7 Dusts Solid particles generated by handling,crushing, grinding, rapid impact, detona-tion, and aging of organic or inorganicmaterials such as rock, ore, metal, coal,wood, grain, etc. Dusts do not tend toflocculate except under electrostaticforces; they do not diffuse in air but tendto settle under the influenc
