Abstract
A portable gas-monitoring instrument for measuring formaldehyde (HCHO) concentrations in indoor air has been commercially available. The instrument is the FP-30, which can be purchased from RIKEN KEIKI Co., Tokyo, Japan. An important feature of the instrument is its easy operation. However, the instrument's reliability requires confirmation.
Repeatability of the FP-30's performance was examined. The coefficient of variation (CV) was 7.5% (n=10) at the mean HCHO concentration of 0.040 ppm. The regression equation was y=0.825x+0.013 (n=19), where x is the HCHO concentration measured by the standard DNPH/HPLC method, and y is that measured by the FP-30 instrument. The correlation coefficient was 0.958.
HCHO concentrations in wooden detached houses and college buildings were measured with the FP-30 instrument in August 2004. The subjects of the investigation were newly built houses. Since July 2003, HCHO emissions from construction materials in houses and buildings have been regulated by ordinances issued by Japan's Ministry of Land Infrastructure and Transport.
The levels of HCHO in wooden detached houses in three cases (measured points n=6) were 0.036-0.090 ppm (average level: 0.058ppm). The levels of HCHO in buildings ten years or two years after construction were 0.040-0.165 ppm and 0.040-0.220ppm, respectively.
