Toward Better Buildings. Resources for Managing IAQ during Construction

Transcription

1 Toward Better Buildings Resources for Managing IAQ during Construction 26

2 BY DONALD WEEKES, WANE A. BAKER, AND JACK SPRINGSTON EEPA estimates that, on a yearly basis, many Americans spend an average of ninety percent of their time indoors, where concentrations of certain pollutants may be two to five times higher than outdoor levels. Over the past few decades, this confluence of pollutants and people has led to the development of the indoor air quality (IAQ) field as a sub-category of industrial hygiene practice. Since the late 1990s the IAQ field has grown rapidly, and many IAQ practitioners have spent virtually their entire careers working in offices, schools, and homes, rather than traditional IH settings such as factories and manufacturing facilities. This article discusses the unique IAQ issues associated with construction sites and reviews guidelines that focus on construction and IAQ. It also introduces the requirements in the latest version of the Leadership in Energy & Environmental Design (LEED) program for construction IAQ management plans, and for the assessment of select IAQ parameters following completion of construction, but prior to occupancy. With this information, industrial hygienists who want to provide IAQ services during the construction process will be better able to meet their clients needs. CONSTRUCTION HEALTH AND SAFETY In recent years, IAQ practitioners, industrial hygienists, and other professionals such as architects and building scientists have realized the need to address potential IAQ issues in buildings prior to their construction and, in some cases, even before they are designed. In fact, managing indoor environmental quality (IEQ) a term that includes IAQ plus complementary indoor stressors during building construction and renovation has become commonplace and has even spawned its own specialty practice. For many health and safety professionals working in construction, worker safety has been the primary concern, with IEQ an afterthought at best. Certainly worker safety on construction sites remains a priority. At the recent annual meeting of the Voluntary Protection Program Participants Association in Nashville, OSHA Administrator David Michaels noted that the fatality rate in the construction sector rose from 9.1 per 100,000 fulltime equivalent (FTE) workers in 2011 to 9.5 in 2012, with workplace deaths in private-sector construction jumping from 738 fatalities in 2011 to 775 fatalities in 2012 a 5 percent increase. Fatality rate in the construction sector per 100, per 100,

3 However, many construction professionals have been asked to become more familiar with IEQ, including practices necessary to preclude IEQ issues once a building is occupied. To be effective, IEQ practitioners must become more familiar with construction processes and how they can negatively impact the indoor environment. For example, construction activities commonly generate and disperse a wide range of airborne contaminants, including particulate matter (dust and fibers, for example), chemical substances (volatile organic compounds), and biological aerosols (fungal spores, pollen), that can be irritating to occupants and lead to IEQ complaints. These activities can induce a variety of adverse health effects, such as mucous membrane irritation, exacerbation of asthma, respiratory illness and/or contact dermatitis. IEQ REFERENCES Fortunately, a number of excellent resources on IEQ and construction are readily available. Several are summarized below. IEQ Web page. The NIOSH web page Maintaining Indoor Environmental Quality (IEQ) during Construction and Renovation, available at bit.ly/nioshieqconstruction, presents information on common IEQ problems that can occur during new construction or renovation. In addition to links for related online resources, the page includes a helpful bulleted list of actions that building owners and managers should take to help prevent IEQ issues during construction in their building. Design resources. Building on the successful IAQ Tools for Schools Action Kit, EPA s IAQ Design Tools for Schools at forschools is targeted toward construction-related IEQ issues in K-12 schools. With colorful illustrations and well-designed checklists, this is a useful and engaging resource. We ve found that much of this information, including practices that contractors can adopt to reduce the potential for IAQ problems, is relevant for any construction site, not just schools. IAQ guide. ASHRAE s Indoor Air Quality Guide: Best Practices for Design, Construction, and Commissioning at provides excellent insight into IEQ and building design. Available as a free download, this 700-page guidance document has two sections: the first summarizes eight objectives for achieving good indoor air quality, while the second provides authoritative, detailed guidance on these objectives. Co-developed by ASHRAE, EPA, the U.S. Green Building Council (USGBC), the American Institute of Architects (AIA), the Building Owners and Managers Association (BOMA), and the Sheet Metal and Air-Conditioning Contractors National Association (SMACNA), the guide covers moisture control, the limiting of indoor and outdoor contaminants, and the reduction of contaminant concentrations through ventilation, filtration, and air cleaning. Guidelines for occupied buildings. SMACNA s publication IAQ Guidelines for Occupied Buildings under Construction (second edition) is a fundamental, practical resource. It focuses on maintaining satisfactory IEQ in existing, occupied buildings that are undergoing construction or renovation activities. This guide takes a pragmatic approach to a range of topics, including common sources of IAQ contaminants during construction; the design and operation of heating, ventilating and air-conditioning (HVAC) systems during construction; effective isolation of construction areas to prevent IAQ problems for occupants; moisture control during construction; and IAQ compliance monitoring during construction. There is also a chapter on troubleshooting typical complaint scenarios. Mold guidelines. Published in 2004, the Canadian Construction Association s booklet Mould Guidelines for the Canadian Construction Industry is another useful resource for IEQ professionals. Although the primary focus of the publication is mold prevention, the booklet is also a practical guide on how to avoid construction practices that may lead to microbial growth. LEED, IEQ, AND CONSTRUCTION As part of its LEED program, the USGBC has developed a comprehensive strategy for optimizing IEQ and minimizing potential air quality problems that may arise from the construction process. The LEED strategy addresses several related issues that can affect IEQ, including minimum IAQ performance standards, control of environmental tobacco smoke, use of low-emitting materials, ventilation, control of chemical and particle pollutant sources, thermal comfort, and introduction of daylight into the work space. The LEED construction IAQ management plan is a simple but effective protocol for ensuring that indoor air quality is acceptable during the construction process and prior to building occupancy. 28

4 Toward Better Buildings IAQ Management Plan In the most recent version of LEED for New Construction (LEEDv4), a credit is awarded for the development and implementation of an IAQ management plan for the construction and pre-occupancy phases of the building. In particular, LEEDv4 includes a requirement that all applicable recommended control measures outlined in chapter 3 of the SMACNA IAQ guideline be met or exceeded. Such control measures include protection of the HVAC system during construction, source control of potential IAQ contaminants, product substitution (when appropriate), pathway interruption to prevent the dispersal of IAQ contaminants to other sections of the building, housekeeping, scheduling of construction activities, and occupant relocation. To preclude unwanted microbial growth, LEEDv4 also requires the protection of absorptive materials stored on site from moisture damage, and prohibits the use of all tobacco products within 25 feet of any entrances to the construction site. In addition, LEED states that permanently installed HVAC systems should not be operated during construction unless filters with a minimum efficiency reporting value (MERV) of 8, as determined by ASHRAE , are installed at each return air grille and return or transfer duct. The temporary filters must be removed and the permanent filters replaced immediately before occupancy begins. IAQ Assessment LEED awards additional credits for establishing improved IAQ following the completion of new construction and during initial occupancy. To qualify for these credits, improved IAQ can be achieved via either a building flush-out or by performing air testing. For the first option, the IAQ professional can choose to perform the building flush-out either before or during occupancy. The before occupancy path requires that the building be flushed out by supplying at least 14,000 cubic feet of outdoor air per square foot of gross floor area. The during occupancy path requires that a minimum of 3,500 cubic feet of outdoor air per square foot of gross floor area be delivered before the space is occupied, and then a minimum of 0.3 cubic feet per minute (CFM) of outside air be delivered per square foot of gross floor area until a total of 14,000 cubic feet of outdoor air has been delivered to the space. During each day of the flush-out period, ventilation must begin at least three hours before occupancy and continue through occupied hours. Considering their desire for analytical data, the second option, air quality monitoring, will likely be Table 1. LEEDv4 Maximum Concentration Levels (By Contaminant and Testing Method) CONTAMINANT MAXIMUM CONCENTRATION Formaldehyde 27 ppb 16.3 ppb MAXIMUM CONCENTRATION (HEALTHCARE ONLY) ASTM AND U.S. EPA METHODS ASTM D5197; EPA TO-11 or EPA Compendium Method IP-6 ISO METHOD Particulates (PM 10 for all buildings; PM 2.5 for buildings in EPA nonattainment areas, or local equivalent) Ozone (for buildings in EPA nonattainment areas) PM 10 : 50 μg/m 3 PM 2.5 : 15 μg/m 3 20 μg/m 3 EPA Compendium Method IP ppm ppm ASTM D Total volatile organic compounds (TVOCs) 500 μg/m μg/m 3 EPA TO-1, TO-15, TO-17, or EPA Compendium Method IP Target chemicals listed in CDPH Standard Method v1.1, Table 4-1, except formaldehyde CDPH Standard Method v , Allowable Concentrations, Table 4-1 CDPH Standard Method v , Allowable Concentrations, Table 4-1 ASTM D5197; EPA TO-1, TO-15, TO-17, or EPA Compendium Method IP , Carbon monoxide (CO) 9 ppm; no more than 2 ppm above outdoor levels 9 ppm; no more than 2 ppm above outdoor levels EPA Compendium Method IP ppb = parts per billion ppm = parts per million μg/m 3 = micrograms per cubic meter 29

5 Toward Better Buildings more appealing to most industrial hygienists. Air testing must be completed following construction but prior to occupancy, although there is an exception for retail projects where the air testing can be conducted within fourteen days of occupancy. LEEDv4 lists several air contaminants that must be quantified, including formaldehyde, particulate matter, ozone, total VOCs, and carbon monoxide. The maximum concentration for each of these contaminants appears in Table 1, along with the acceptable sampling and analytical methods (ASTM, EPA, ISO) for measuring these contaminants (maximum concentrations for healthcare facilities are listed in a separate column). Of particular interest is the new VOC emission testing requirement, which stipulates that products must be tested and determined to be compliant in accordance with California Department of Public Health Standard Method v This option requires that all samples be collected during regular occupied hours with the ventilation system started at the normal start time, and operated at the minimum outdoor air flow rate through the duration of the sample collection period. PREPARING FOR CONSTRUCTION SITES For IEQ practitioners whose field experience is limited to remediation projects involving asbestos, lead-based paint, and mold, a building construction site can be a chaotic, unfamiliar workplace. Although such remediation projects are often performed as part of the demolition or renovation of existing buildings, they generally take place prior to the arrival onsite of other construction trades, such as plumbers, carpenters, and electricians. As a result, it can be daunting to visit a construction site for the first time and witness the myriad activities associated with the construction of a new office building, hotel, school, or retail space. Providing helpful, effective IAQ advice to experienced construction foremen, workers, and project managers that they perceive as being worth their time and trouble can be challenging for experienced practitioners as well as first-timers. Knowing the guidance documents and related resources described in this article can help you gain the confidence of construction professionals interested in protecting and improving the indoor environment. DONALD WEEKES, CIH, CSP, is a partner with InAIR Environmental Ltd. in Ottawa, Ont., and an AIHA Fellow. He can be reached at don.weekes@ inairenvironmental.ca or (613) WANE A. BAKER, PE, CIH, is an instructor with the Graduate Training Program at the Trane Company in La Crosse, Wisc. He can be reached at [email protected] or (608) JACK SPRINGSTON, CIH, CSP, is a senior project manager with TRC Environmental in New York City, an AIHA Fellow, and chair of AIHA s Indoor Environmental Quality Committee. He can be reached at [email protected] or (212)