Part 1: Application and Purpose
Part 2: Test Results and Data
Part 3: Cross Sensitivity and Analysis


The Quality Housing Components Certification System was introduced in 1974, as part of the effort to provide superior performance and serviceability, to housing in Japan. The purpose of the system was to stimulate the development of advanced construction components, in terms of quality, cost, availability, and serviceability. The intent of these efforts was to improve living standards and safety of the consumers. In 1999 indoor air quality standards for housing were introduced. A limit of 0.08 PPM for formaldehyde was legislated for new housing.

Formaldehyde is a particularly ubiquitous chemical. It is emitted from wood and polymer products used in the construction of housing. The certification of an indoor air level in the 0-0.08 range posed a significant measurement problem: To accurately measure such low levels of formaldehyde, using cost effective portable instruments. In addition, the solution needed to be performed by personnel with little or no special instruction. This required an advance in measurement technologies.

Test studies were conducted to qualify instruments that can attain the required level of accuracy. A total of five instruments, with different sensing technologies were selected. The first two instruments used absorption tubes, a second instrument used a colorimetric method, and the other two were electronic meters. One of the meters used a semiconductor and the other an electrochemical sensing element. The brief description of the instruments and the various techniques used in the study are given in Table I.



Table I
Formaldehyde Measuring Instruments Tested


Manufacturer
Kitagawa
GasTech
Biocheck-F
Cosmos, Formtector

ESC Z300JA

Measurement Technology
Absorption tubes, 0.3 l/min. for 30 min.
Absorption tubes, 0.2 l/min. for 30 min.
Color Change, free convection, 30 min. exposure
Semi-conductor, Free convection, average of six measurements, one/5 min.
Free convection, electrochemical/filter, one point.


The required tests were performed in the labortory of The Ministry of Construction, in Tsukuba, Japan. Mitsubishi Chemical Co.'s personnel performed the actual tests. They were funded by The Ministry of Construction, through the Center for Better Living (CBL).

Test Results and Data-->