Performance Evaluation of Real Time Formaldehyde Monitors: PTR-MS and Interscan 4160-500B Portable Monitor

Exposure to volatile organic compounds (VOCs) in buildings is a health hazard. Of particular concern is formaldehyde, a ubiquitous carcinogen emitted from furnishings and adhesives in homes and offices. Practitioners and researchers in the area of building performance are very interested in measuring formaldehyde in homes, and they need instrumentation that responds immediately. Current formaldehyde monitoring techniques are hampered by interfering substances in the sample airstream, compromising measurement accuracy and leading to drift. Many experts are now using a tabletop real-time formaldehyde instrument, the Interscan 4160-2, that LBNL researchers have found to be very sensitive to water vapor and low levels of volatile organic compounds (VOCs). Unless ways are found to remove these interferences, relying on the Interscan's readings in buildings will lead to the wrong conclusions about formaldehyde levels and could trigger subsequent unnecessary expense and/or inappropriate responses.

This report describes a solution to the challenge of monitoring formaldehyde levels accurately in real-time, LBNL's new VOC True Read device that is now ready for commercialization. Its innovative trap design strips water vapor, alcohols, and other VOCs from the sample, allowing formaldehyde — or other target gases — to pass through to a detector. The filter presents an economical answer to a long-sought method for sensitive formaldehyde measurement because it can be attached to, and can retrofit, in-place sensors to increase their detection accuracy. The filter's internal structure can be arrayed various ways to adsorb other interferents, as needed. The device answers a widely recognized need for accurate, long-term, inexpensive, real-time monitoring of building air for formaldehyde to assist exposure assessment and demand-controlled ventilation. It can be added to real-time or passive monitors for formaldehyde, such as electrochemical sensors in handheld devices or table-top monitors with sensors that respond to oxygenated VOCs as well as formaldehyde.