Indoor Environmental Quality During Construction and Renovation

If you have worked as a lab manager long enough, you have probably lived through at least one construction or renovation project. Maybe it went smoothly and you can barely remember the details. Most likely, however, a number of things went wrong and there are memories that you want to forget, perhaps even a nightmare or two. In this month’s column, we intend to help you avoid replaying those bad scenes and enlighten you about how to proactively eliminate the most common errors.

In order to maintain employee and occupant health, comfort and productivity, it is essential to manage indoor environmental quality (IEQ) effectively. Below, we provide a few guidelines to assist you in reducing and minimizing any negative impacts from renovation projects or adjacent new construction on occupied spaces, and hopefully preserve acceptable indoor environmental conditions both during and after your renovation project.

The first step is to involve your Environmental Health and Safety (EH&S) office as early as possible. Most EH&S programs will have an IEQ policy that will make your job much easier. If the EH&S office is given the opportunity to review and comment on architectural or engineering submittals, many of the pitfalls can be avoided altogether. If any of the recommendations given here are at variance with traditional/consensus guidelines or local codes, try to apply the more stringent of the two. Make sure any exceptions or variations are reviewed and approved by the EH&S office.

The most common IEQ concerns stemming from construction and renovation projects are transient smells, nuisance odors, noise and dust. Building occupants can experience mucous membrane irritation and headaches, as well as aggravated allergies or asthma symptoms, even with low-level exposures to contaminants. In addition, excessive noise has a definite effect on focus, concentration and productivity. If these conditions are repeatedly introduced into the occupied areas, the workers are going to let you know about it, and rightfully so. However, most of these conditions that affect IEQ , and thus employee comfort, productivity and health, are preventable. After years of dealing with IEQ complaints resulting from construction and renovation adjacent to occupied spaces, we recommend the following tips to keep your project moving toward completion and your employees happy, healthy and productive.

• Prior to beginning your construction or renovation project, ensure that the ventilation systems supporting the adjacent, occupied spaces are generally consistent with all appropriate recommendations of the latest version of the American Society of Heating, Refrigeration and Air Conditioning Engineers Standard 62, Ventilation for Acceptable Indoor Air Quality.¹ This might be a good time to perform a test and balance of the ventilation system, unless one has been done in the past twelve months.
• Separate construction/renovation project areas from adjacent, occupied areas with full-height hard wall barriers. These type of barriers will effectively block any transmission of dust, odors or other contaminants and attenuates noise, thus isolating the construction zone from the adjoining work areas.
• Maintain the construction/renovation areas with a slight negative air pressure, relative to the adjacent, occupied spaces. Should positive pressurization occur, then contaminants, dust and odors could push into nearby offices and labs. Set up and maintain negative pressurization during the test and balance by adjusting the HVAC system or installing additional exhaust ventilation to support the construction/renovation work. If local exhaust ventilation is used, for example, specialized hoods or snorkel systems, it should follow the recommendations of the American Conference of Governmental Industrial Hygienists’ Industrial Ventilation, a Manual of Recommended Practice.²
• For the construction/renovation work, try to segregate all areas utilized for containment. Move any odor-or contaminant-generating activities away from the return air system and ensure that adequate exhaust air is provided. Alternatively, you could block the return air vent temporarily in the construction/ renovation area.
• Make sure regular, daily housekeeping is performed to prevent construction workers from tracking dust and debris outside the work area and into occupied spaces. If possible, set up decontamination zones or antechambers so that workers can wipe down and clean off before leaving the construction area. The use of sticky mats greatly reduces the dust and debris carried by worker footwear. Your facility housekeeping staff will also appreciate their use.
• Ask the facility maintenance personnel to perform a routine checking and replacing of HVAC system air filters throughout the project. Use more efficient filters if dust loading in adjacent occupied areas becomes excessive. We recommend pleated, extended surface area filters with a minimum dust spot efficiency of 60 percent (MERV 11).
• Many construction and renovation projects necessitate the use of equipment that produces odors or contaminants, and this equipment is often set up outside. Examples include roofing tar pots, spray equipment, pressure washers, portable gas- or diesel-powered engines or generators, and portable showers/ lavatories. Any such equipment set up outside must be carefully located well away from any ventilation system air intakes and building entrances to prevent the re-entering of contaminants.
• Make sure that Material Safety Data Sheets are maintained on-site for all chemical products used during the construction/renovation process. When the inevitable calls start coming in, you will need to know what the contaminants are so that the appropriate actions can be taken.

Construction and renovation projects are always fraught with unknowns and the unexpected. Even if you are extremely diligent, chances are something will upset the delicate balance and cause unacceptable indoor environmental quality conditions in unintended places. There may be times when controls are just not possible. When these cases arise, your only alternative may be to have your contractors schedule a continuation of the work after regular work hours or on weekends. It is not often that you run into these situations, but it is a good idea to consider adding contingencies to the project budget, just in case. Good luck with your next construction or renovation project, and remember—Safety First!

References

1. Ventilation for Acceptable Indoor Air Quality. American Society of Heating, Refrigeration and Air Conditioning Engineers Standard 62-2009. Atlanta, Ga.
2. Industrial Ventilation, a Manual of Recommended Practice. American Conference of Governmental Industrial Hygienists. 27th Edition, 2010. Cincinnati, Ohio.