So far, there was no validated European method available for emissions control, prompting the creation of a specific working group (WG 40) within the Technical Committees 264 (CEN TC 264) to publish a qualified method for quantifying formaldehyde emissions from stationary sources (such as power plants, incinerators, petrochemical facilities, and industrial plants using combustion for energy purposes).

Preliminary test trials were conducted to assess (1) the sampling protocol and (2) the analytical technique. From a measurement standpoint, two methods were selected: EPA 323-VDI 3862-6 and VDI 3862-2. Each new method prepared by CEN must undergo field verification under real conditions to ascertain its metrological properties (precision, bias, reproducibility, and repeatability), costs, and personnel training requirements. To this end, two measurement campaigns were conducted, yielding significant insights into the H-CHO sampling procedure.

Due to the typically high water levels present, condensation during sampling is critical and can lead to unpredictable errors; impingers provide reliable responses. Sampling in pure water appeared unstable, but using an H2SO4 solution resolved this issue, thus it was recommended.