In April 2008, the State of California adopted an airborne toxic control measure (ATCM) to reduce formaldehyde emissions from composite wood products, proposed by the California Air Resources Board (CARB), part of the California Environmental Protection Agency. Phase 1 started in January 2009, and at the end of the implementation, in July 2012, formaldehyde emission limits will range between 0.05 and 0.13 ppm, depending on the type of products, based on the ASTM E 1333 Large Chamber Method.
These new limits are in the order of the limits of detection of the current analytical methods presently used, and rendered the chromotropic acid reaction, on which the ASTM E 1333 is based, with a limit of detection of 0.01 ppm less precise.
The use of Near Infrared technology was investigated in 2009/2010. This analytical technique was not initially considered to be sensitive enough to measure formaldehyde emissions at very low levels. Recent developments in the broadband sources of near infrared radiation available and the type of detectors used have contributed in recent years to improve spectral stability and sensitivity. Some instruments have recently been tested in Europe and equipment suppliers claim that these systems can be used for online monitoring of formaldehyde emissions. This analytical technique is not recognized at this time by Canadian and US regulatory authorities and more testing was required to demonstrate the system’s reliability. Commercial products with very low free formaldehyde have been tested in 2009 with NIR sensors and results have been correlated with the ASTM E 1333 Large Chamber test results. At least one Canadian panel manufacturer has already expressed interest in running a mill trial. Results will be presented to regulatory authorities.