Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, HETA 2011-0004-3128, 2011 May; :1-15
NIOSH investigators evaluated a federal government office on December 15-16, 2010, after receiving a technical assistance request from the property manager. The office employees believed a chemical odor present since the building opened in 2007 was responsible for their symptoms, which included nausea; headache; and eye, nose, throat, and respiratory irritation. We measured temperature, RH, CO2, and CO in the office. We took air samples for H2S, formaldehyde, and VOCs in the office and in two nearby businesses for comparison. We took carpet and paint samples from the office and analyzed them for VOCs. We also looked for water damage in the office and checked the HVAC system. We surveyed employees about odors in the office, asking them to describe the odors and health concerns they associated with the odor. The CO2 concentrations inside the office had a range of 750-1160 ppm, while the CO2 concentrations outdoors had a range of 420-440 ppm. Usually, CO2 concentrations are used to determine the adequacy of an HVAC system, but not for sparsely occupied areas such as this office. However, with only two employees working, the fact that indoor CO2 concentrations were nearly triple the outdoor concentration indicated the HVAC system was likely not introducing much outdoor air into the occupied office areas. Temperature in the office had a range of 71-75 degrees F and RH had a range of 21-28 percent, compared to outdoor temperature, which had a range of 18-27 degrees F and RH at 20 percent. These levels are within the recommended thermal comfort guidelines for the winter season. The CO concentrations were low (0-0.1 ppm) and were likely caused by the entrance door to the office being located adjacent to a parking lot. No water damage in the office was identified. No H2S was detected (detection limit was 1 ppm) and formaldehyde was less than 0.02 ppm in the office and ranged up to 0.03 ppm in the adjacent businesses. The formaldehyde concentrations are below some exposure guidelines for office spaces (0.05-0.10 ppm) but above other recommended indoor air levels for offices (0.003 ppm). In area air samples collected from carpeted areas of the office, we identified VOCs (specifically alcohols) that were similar to VOCs from a headspace analysis of carpet taken from the office. These VOCs were not found in air samples taken in non-carpeted areas of the office or from two nearby businesses that were not carpeted. This suggests that either the carpet or incompletely cured carpet adhesive may be the source of the odor. Incomplete curing of the carpet adhesive can happen when the concrete slab onto which the carpet was installed had excessive alkalinity and water vapor. We also surveyed employees about odors in the office, asking them to describe the odors and any health concerns they associated with the odor. All eight office employees returned surveys. Six reported having smelled an odor at the office, and four still smelled the odor. The odor was described as a glue, adhesive, plastic, chemical, or cleaner smell. Two employees mentioned burning of their eyes and one mentioned occasional headaches during work, which are irritation symptoms typically associated with indoor VOC and formaldehyde exposures. The residential-style electric HVAC system serving the office was well maintained and had been modified in 2010 to introduce outdoor air. Under some conditions the bathrooms and locker rooms were under positive pressure in relationship to the office, meaning that odors from the bathrooms and locker rooms could enter into the occupied office spaces. We recommended removing the carpet and adhesive to eliminate the source of the odor. We recommended running the HVAC system continuously to minimize stagnant air, evaluating the HVAC system to determine if enough outdoor air is being introduced into the occupied spaces, and to determine if bathrooms are under negative pressure. We recommended that employees minimize other sources of odor, like air fresheners. We also recommended that employees be informed in advance about any remediation efforts, such as carpet and adhesive removal and the installation of new flooring.
Office-equipment; Office-furniture; Office-workers; Odor-threshold; Odors; Indoor-air-pollution; Indoor-environmental-quality; Organic-compounds; Organic-vapors; Oxides; Dioxides; Volatiles; Temperature-effects; Temperature-measurement; Relative-humidity; Air-quality-measurement; Air-sampling; Sulfides; Formaldehydes; Paints; Adhesives; Water-analysis; Ventilation-systems; Heating-systems; Air-conditioning-equipment; Air-flow; Air-monitoring; Outdoors; Alcohols; Exposure-assessment; Exposure-levels; Exposure-limits; Alkalis; Health-surveys;
Author Keywords: Regulation, Licensing, and Inspection of Miscellaneous Commercial Sectors; odor; irritation; office; VOCs; indoor environmental quality; IEQ; ventilation; carpet; carpet adhesive