This study was conducted to identify suitable methods for measurement of formaldehyde in ambient air at sub-ppm levels. Experiments were designed to compare four different analysis procedures including NIOSH Method No. 3500, NIOSH Method No.2541, EPA ...
This study was conducted to identify suitable methods for measurement of formaldehyde in ambient air at sub-ppm levels. Experiments were designed to compare four different analysis procedures including NIOSH Method No. 3500, NIOSH Method No.2541, EPA Method No. 67 and passive tube method under favorable conditions(laboratory exposure chamber) and in ambient air of the household furniture shops.
The results were as follows ;
1. Absolute bias by each method were less than 26.8% at the theoretical exposure concentration of 0.21ppm and all methods except the passive method produced precise results at this levels. Use of the NIOSH Method No. 3500 indicated accuracy was approximately 1.5~2.8 times higher than those determined by NIOSH Method No. 2541 and EPA Method No. 67.
2. EPA Method No. 67 had the best precision and accuracy at 0.12ppm level similar to the current regulatory limit for the formaldehyde in ambient air.
3. The amounts of released formaldehyde for household furniture shops were 0.040ppm by NIOSH Method No. 3500, 0.051ppm by NIOSH Method No.2541, 0.054ppm by EPA Method No. 67 and 0.096ppm by passive tube method, respectively. The concentrations indicated by passive tube method were consistently higher than those measured by the other methods. No statistically significant differences of formaldehyde concentrations among ambient air except the passive tube method were found(p<0.05).