Environmental Engineering Reference
In-Depth Information
Table 4.4
Formaldehyde Concentrations in U.S. Houses
Measured in the Period 1978-1989
Concentration (ppmv)
Study
N
Range
Mean
Median
Urea-Formaldehyde Foam Insulated Houses
New Hampshire
71
0.01-0.17
—
0.05
Consumer Product
Safety Commission
636
0.01-3.4
0.12
—
Manufactured Houses
Washington
74
0.03-2.54
—
0.35
Wisconsin
137
<0.10-2.84
—
0.39
California
663
—
0.09
0.07
Indiana
54
0.02-0.75
0.18
0.15
Conventional Houses
Texas
45
0.0-0.14
0.05
—
Minnesota
489
0.01-5.52
0.14
—
Indiana (particle board
underlayment)
30
0.01-0.46
0.11
0.09
California
51
0.01-0.04
0.04
—
Source:
From Godish, T.J.,
Indoor Air Pollution Control
, 1st ed., Lewis
Publishers, Chelsea, MI, 1989. With permission.
constructed in the U.S. and Canada, concentrations are unlikely to exceed
0.10 ppmv, with concentrations <0.05 ppmv the norm. In office buildings,
HCHO levels are rarely >0.05 ppmv, with concentrations in the range of 0.02
to 0.03 more common.
3.
Factors affecting formaldehyde levels
Formaldehyde levels in building environments are affected by a number of
factors. These include the potency of formaldehyde-emitting products
present, the loading factor (m
2
/m
3
), which is described by the surface area
) of inte-
rior spaces, environmental factors, materials/product age, interaction effects,
and ventilation conditions.
ically differed in their emission potential. These differences have decreased
with product improvements. Medium-density fiber board and acid-cured
finishes have been among the most potent formaldehyde-emitting materials.
(m
2
) of formaldehyde-emitting materials relative to the volume (m
3
Mobile homes have had the highest reported con-
centrations of HCHO. This has been the case in good measure because of
the high loading rate of formaldehyde-emitting wood products. In the past,
mobile homes were constructed using particle board floor decking, Luan
plywood wall covering, and wood cabinets (made from various combina-
a.
Loading factor.
