Home environment humidity

Wolkoff, 1998 Haghighat and de Beilis, 1998). Table 15.7, for example, shows the effects of temperature and relative humidity on the emissions of particular compounds associated with carpet, PVC flooring, sealants, varnish, and wall paint (Wolkoff, 1998). Interestingly, exposure of these samples to N2 rather than air also increased the emissions in some cases. However, using increased temperatures to bake-out buildings and hence lower the concentrations of indoor VOCs does not appear to be particularly effective. For example, Bayer (1991) reports that the total VOC concentrations from particleboard are about the same after as before a 5-day bake-out at 88°C. Similarly, significant levels of HCHO have been observed in a mobile home even after 20 years of use in a hot ambient air environment (Pitts et al., 1989 see later). 

These test chambers can be incorporated to the enzymatic methods for formaldehyde determination. Formaldehyde emissions of a product, or mix of products, to the ambient air can be collected in distilled water or 1% sodium bisulfite as the absorbing solution. After collection, formaldehyde samples are analyzed as described above. In the mobile home simulator test method (2J, double or triple impingers, which are placed in series, should be used in order to collect all of the formaldehyde vapor. The test conditions should simulate the actual environment. Several factors such as temperature and relative humidity of the system including the specimens and background of formaldehyde in the test chamber, affect the precision and accuracy of the results. It has been shown that a 7 C change in temperature doubles the emission level (L). The temperature of the test chamber should be... 

Breakdown of protective oxide films on many metals, e.g., aluminum, requires that environmental stresses exceed some threshold condition. Aluminum is likely to rapidly pit when exposed to high chloride concentrations at humidity levels sufficiently high to adsorb several mono-layers of moisture. Most home and office environments do not cause these conditions. 

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