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Volatile organic compound comparison of several ventilation systems.

Calvert C; Lawrence R; Hudnall J; Duling M; Berardinelli S; Coffey C
American Industrial Hygiene Conference and Exposition, May 10-15, 2003, Dallas, Texas. Fairfax, VA: American Industrial Hygiene Association, 2003 May; :62
The ventilation system of a government facility consists of six commercial air-handling units (AHUs), three operating on 100% outside air intake and three using recycled mixed air (15-20% outside air). All AHUs used 85% efficient Purolator Defiant Filters with Koch prefilters. A strong odor emanating from used ventilation filters in one of the single-pass systems was noticed during annual routine maintenance. A study was undertaken to determine the cause of the odor and identify the source. To see if there was the potential for this problem to exist elsewhere, a second building of the same agency in another city was also investigated. The AHUs contained Columbus Industries average-efficiency, single-component bag filters with low-efficiency pre-filters. The study was conducted in both buildings over a period of several months in order to determine if the problem was time-related or location-specific. Air samples were collected in evacuated canisters for further analysis by gas chromatography-mass spectroscopy (GC-MS). Samples were collected in all AHUs upstream and downstream of the filter bank. Portions of new and used samples of the pre-filter and filter media were collected for GC-MS headspace analysis. The analysis of the air samples collected in the air intakes (outside air) from both buildings was very similar. The samples contained low concentrations (<10 ppb) of chloromethane, 1,3-butadiene, 3-chloropropene/allyl chloride, methylene chloride, and acrylonitrile. These same compounds were found in higher concentrations in the used filter headspace samples for both types of filter media of both buildings. It is concluded that the filter acts as a large vapor collection bed regardless of the filter media for these compounds that are found in outside air. This research and subsequent analysis may be useful in evaluating building indoor air quality and might lead to improved filter replacement schedules.
Organic-compounds; Ventilation-systems; Filters; Air-samples; Gas-chromatography; Indoor-air-pollution; Indoor-environmental-quality
74-87-3; 106-99-0; 107-05-1; 107-05-1; 107-13-1; 75-09-2
Publication Date
Document Type
Fiscal Year
NIOSH Division
Priority Area
Work Environment and Workforce: Indoor Environment
Source Name
American Industrial Hygiene Conference and Exposition, May 10-15, 2003, Dallas, Texas
Page last reviewed: December 18, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division