Getting Ventilation Right
A Primer on Regulations, Standards, and Guidelines


To provide a healthy and comfortable environment, ventilation is necessary in every human occupancy; it is the one industrial hygiene control that is always required, and every occupational health and safety professional needs to know how to apply and manage it.

But how do we know when we (or others) have the ventilation right? The best way is to compare existing or planned conditions and equipment with established standards of good practice. When we use and follow recognized SGP, we are more likely to provide better employee health and comfort, enhance performance, minimize costs, and protect ourselves from legal actions such as OSHA citations and third-party lawsuits. This article provides examples of ventilation SGP ranging from the “required” to the merely “suggested.” Some overlap, some have different requirements, and some are more stringent than others. Because there can be more than one SGP, most IH professionals look for and follow the current “standard of practice”—the one recognized to be the most effective in light of costs, legal requirements, suitability, and other factors. (And, in the event of legal action, it is the one the opposing attorney will likely ask about to determine whether you followed it.)
OSHA is the primary federal agency with ventilation-related regulations for employee occupancies. The term “regulation” implies a legal requirement for complying with its provisions. OSHA has promulgated a number of rules and regulations that refer to what it calls “engineering controls”; in 29 CFR 1910 - General Industry, for example, there are more than 80 references to engineering controls. Unfortunately, many OSHA ventilation regulations and rules are both outdated and considered secondary to other standards. If actual exposures to employees are within OSHA’s permissible exposure limits, the agency will often assume compliance with ventilation regulations. 
Unfortunately, many OSHA ventilation regulations and rules are both outdated and considered secondary to other standards.
, PE, CIH (VS 2012), is an industrial hygiene engineer with broad experience in ventilation used for emission and exposure control. He is the author of many books and training courses, and is current chair of the ANSI Z9.2 and Z9.10 subcommittees. His full biography can be found
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One good current OSHA regulation, however, covers lab ventilation (29 CFR 1910.1450 - Occupational Exposure to Hazardous Chemicals in Laboratories). This rule requires employers to follow a chemical hygiene plan, which includes measures to ensure the proper use and functioning of fume hoods, methods used to ensure adequate performance of ventilation equipment, and containment devices (such as glove box hoods) that must be used with certain carcinogenic materials.
Building and fire codes, also considered mandatory, vary by location but usually include provisions for ventilation. They are normally adopted at a local level (city, county, or state) and are enforced by building inspectors.
Several organizations developed model building codes that were used for decades--for example, the Basic Building Code of the Building Officials and Code Administrators; the Uniform Building and Mechanical Codes (UBC, UMC) of the International Conference of Building Officials; and the Southern Building Code (SBC) by the Southern Building Code Congress International. These organizations were consolidated into the International Code Council (ICC), which now produces and publishes the International Building Code (IBC), the International Mechanical Code (IMC), and others. Find and use the appropriate codes for your jurisdiction and project. The National Fire Protection Association also develops model fire codes; see, for example, NFPA 91-2015 - Exhaust Systems for Air Conveying of Vapors, Gases, Mists, and Noncombustible Particulate Solids.
Codes are applied when a building is built or new equipment is installed, and they are not typically applied retroactively to older facilities unless remodeling or rebuilding occurs. That said, economic and other forces often influence employers to bring existing facilities up to current fire and building codes. 
“Voluntary” standards of good practice are often generated using a consensus process. Consensus-developed standards are very important in the OHS field. The strengths of this approach are many: standards requirements are determined on a consensus basis by relevant stakeholders; standards are kept up-to-date and represent the state of the art; stakeholders comply voluntarily; the process of developing standards is cost effective; standards tend to be performance oriented (as opposed to specification oriented) and flexible; and standards tend to be user-friendly, usually including “how-to-comply” instructions. OHS consensus standards are (or have been) developed through AIHA; the American National Standards Institute; the American Society of Heating, Refrigerating and Air-Conditioning Engineers; the American Society of Safety Engineers; and other related organizations. Many AIHA members serve on committees that develop consensus standards. (This is a great way to enhance your career and have an influence on our profession.) Some important ventilation consensus standards are discussed below.
ASHRAE standards.
These standards provide health and safety guidance for commercial, office, and school ventilation systems. ASHRAE Standard 62.1, Ventilation for Acceptable Indoor Air Quality, is the premier consensus standard for maintaining adequate indoor air quality in commercial, institutional, and school buildings. ASHRAE Standard 55, Thermal Comfort, provides ranges of temperature and humidity at which 80 percent to 90 percent of occupants will find the environment thermally acceptable. ASHRAE Standard 52, Filter Testing, provides methods for testing air filters in terms of particle diameter capture. ASHRAE Standard 110, Method of Testing Performance of Laboratory Fume Hoods, describes a quantitative procedure for determining the operating capabilities of fume hoods.
ANSI Z9 standards.
These standards provide health and safety guidance for industrial ventilation systems. All describe recommended practices for the design, operation, and maintenance of ventilation equipment to provide a safe atmosphere in manufacturing, production, and any employment environments where chemicals are encountered. ANSI Z9.1, Open Surface Tank Ventilation and Operation, describes requirements for the building, operation, and maintenance of ventilation systems used to control emissions from open-surface liquid tanks (for example, in plating and metal cleaning operations).  ANSI Z9.2, Fundamentals Governing the Design and Operation of Local Exhaust Systems, is the most important industrial ventilation standard. It describes requirements for the building, operation, and maintenance of local exhaust ventilation systems used to control emissions and employee exposures. It is currently being updated and should be available in early 2018. ANSI Z9.3, Spray Finishing Operations—Safety Code for Design, Construction and Ventilation, covers ventilation systems used to control emissions from spray finishing operations (for example, paint spraying).  ANSI Z9.5, Laboratory Ventilation, covers laboratory ventilation systems. Sections of this standard include scope, references, terms and definitions, general requirements, lab hoods, ductwork, fans, storage facilities, catastrophe potentials, noise control, and good work practices.  ANSI Z9.7, Recirculation of Air from Industrial Process Exhaust Systems, covers the building, operation, and maintenance of recirculating exhaust ventilation systems used for energy conservation. ANSI Z9.10, Dilution Ventilation Systems, covers all kinds of dilution ventilation systems found in occupational settings. Other ANSI Z9 standards cover abrasive blasting operations (Z9.4); grinding, buffing, and polishing (Z9.6); portable ventilation systems (Z9.9); laboratory decommissioning (Z9.11); and biosafety cabinet ventilation (Z9.14).
Guidelines, criteria documents, official recommendations, and reference texts can be very helpful. Sometimes they are even considered the standard of practice when adequate codes, regulations, and consensus standards are not available. A few pertinent examples include the following:
The reference text “Industrial Ventilation Manual” (now in its 29th edition) is considered the “bible of industrial ventilation,” and many consider it the standard of practice for certain elements of industrial ventilation.
“Recommendations for the Management, Operation, Testing and Maintenance of HVAC Systems” (which covers HVAC systems used for maintaining indoor air quality), “Field Guidelines for the Temporary Ventilation of Confined Spaces with an Emphasis on Hotwork,” and “Recognition, Evaluation, and Control of Legionella in Building Water Systems” are just three examples of the many helpful guidelines available from AIHA.
“Guideline for the Commissioning of HVAC Systems” and “Guideline for Preparation of O&M Documentation for Building Systems,” among other ASHRAE guidelines, address the commissioning, operation, and maintenance of HVAC systems.
“A Recommendation for Recirculation of Exhaust Air” is representative of the many NIOSH guidelines available.
“Building Air Quality—A Guide for Building Owners and Facility Managers,” a famous and still-used reference text, covers managing buildings for good indoor air quality; diagnosing IAQ problems; mitigating ventilation problems; and controlling water, moisture, mold, radon, and other air contaminants.
Remember to use the latest versions of all standards and guidelines. Detailed information on ventilation standards can be found in many AIHA publications, such as the “Industrial Ventilation Workbook,” “IAQ and HVAC Workbook,” and “Laboratory Ventilation Guidebook.” For more information, visit the
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Editor's note: This "Building and Fire Codes" section of this article has been updated to provide a more complete list of organizations that developed model building codes.