NFPA 91: Standard for Exhaust Systems for Air Conveying of Vapors, Gases, Mists, and Noncombustible Particulate Solids
Current Edition: 2010 Next Edition: 2015

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NFPA 91:
2010 Edition
Item #: 9110
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What is NFPA 91?
NFPA 91: Document Scope
1.1.1 This standard provides minimum requirements for the design, construction, installation, operation, testing, and maintenance of exhaust systems for air conveying of vapors, gases, mists, and noncombustible particulate solids except as modified or amplified by other applicable NFPA standards. 1.1.2 This standard does not cover exhaust systems for conveying combustible particulate solids that are covered in other NFPA standards (see A.1.1).
This standard provides technical requirements for exhaust systems that will protect lives and property from fires and explosions and minimize damage in the event that such fires and explosions occur. Official document scope
What does NFPA 91 address?
Provisions cover design, construction, installation, operation, testing, and maintenance of exhaust systems for air conveying of vapors, gases, mists, and noncombustible particulate solids except as modified or amplified by other applicable NFPA standards. Specific topics include corrosive materials, air-moving devices, air separation devices, ignition sources, and fire protection.Table Of Contents.
NFPA 91, 2010 Edition: Archived Revision Information
Report on Proposals (ROP)
Report on Proposals (ROP)
Proposals can be submitted for text to be amended or included in NFPA Codes and Standards. Following the Call for Proposals period, the responsible Technical Committee or Panel holds a meeting to consider and act on all submitted proposals. The committee or panel may also develop its own proposals. A document known as the Report on Proposals (ROP) is prepared containing all the Public Proposals, Technical Committees' action on each Proposal, as well as all Committee-generated proposals. The ROP for the document in question is submitted for the approval of the responsible TC or Panel by a formal written ballot. If the ROP does not receive approval via written ballot in accordance with NFPA rules, the Report is returned to the committee for further consideration and is not published. If the necessary approval is received, the ROP is published in a compilation of Reports on Proposals issued by NFPA twice yearly for public review and comment, and the process continues to the next step. The ROP is published and widely distributed and anyone may download or request a copy.
Report on Comments (ROC)
Report on Comments (ROC)
Once the ROP becomes available, there is a 60-day comment period during which time anyone may submit a public comment on the proposed changes documented in the ROP. The committee or panel reconvenes at the end of the comment period and acts on all public comments. This committee or panel may also develop its own comments. As before, approval obtained via written ballot in accordance with NFPA's Regulations is required on all committee and panel actions. All of this information is compiled into a second Report, called the Report on Comments (ROC), which like the ROP, is published and made available for public review for a seven-week period.
Report on Comments(ROC) (PDF, 663 KB)
Motions Committee Report (NITMAM)
Motions Committee Report (NITMAM)
Proposed NFPA documents will be presented for action at the applicable Annual (June) Association Technical Meeting only when proper Amending Motions (Notice of Intent to Make a Motion - NITMAM) have been certified by the Motions Committee of the Standards Council as a proper amending motion. Documents that receive no motions will not be presented at the meeting and instead will be forwarded directly to the NFPA Standards Council for action on issuance. More about the codes and standards making process including NITMAM.
No NITMAMs
Association Technical Meeting
Consent document not presented at Association Technical Meeting. Document will be issued 12/5/2009.
Archived revision information
NFPA 91, 2010 Edition: Archived Revision Information
View archived proposals, comments and other records related to the development of this edition.
Read the archived revision information
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