[Code of Federal Regulations]
[Title 24, Volume 5]
[Revised as of April 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 24CFR3280.406]

[Page 141]
 
                 TITLE 24--HOUSING AND URBAN DEVELOPMENT
 
 CHAPTER XX--OFFICE OF ASSISTANT SECRETARY FOR HOUSING--FEDERAL HOUSING 
        COMMISSIONER, DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT
 
PART 3280--MANUFACTURED HOME CONSTRUCTION AND SAFETY STANDARDS--Table of Contents
 
                           Subpart E--Testing
 
Sec. 3280.406  Air chamber test method for certification and qualification of formaldehyde emission levels.

    (a) Preconditioning. Preconditioning of plywood or particleboard 
panels for air chamber tests shall be initiated as soon as practicable 
but not in excess of 30 days after the plywood or particleboard is 
produced or surface-finished, whichever is later, using randomly 
selected panels.
    (1) If preconditioning is to be initiated more than two days after 
the plywood or particleboard is produced or surface-finished, whichever 
is later, the panels must be dead-stacked or air-tight wrapped until 
preconditioning is initiated.
    (2) Panels selected for testing in the air chamber shall not be 
taken from the top or botton of the stack.
    (b) Testing. Testing shall be conducted in accordance with the 
Standard Test Method for Determining Formaldehyde Levels from Wood 
Products Under Defined Test Conditions Using a Large Chamber, ASTM E-
1333-90, with the following exceptions:
    (1) The chamber shall be operated indoors.
    (2) Plywood and particleboard panels shall be individually tested in 
accordance with the following loading ratios:
    (i) Plywood--0.29 Ft2/Ft3, and
    (ii) Particleboard--0.13 Ft2/Ft3.
    (3) Temperature to be maintained inside the chamber shall be 77 deg. 
plus or minus 2  deg.F.
    (4) The test concentration (C) shall be standardized to a level 
(CO) at a temperature (tO) of 77  deg.F and 50% 
relative humidity (HO) by the following formula:

C = CO x [1 + Ax (H - HO)] x 
    e-R(1 / t - 1 / t O)

where:

C = Test formaldehyde concentration
CO = Standardized formaldehyde concentration
e = Natural log base
R = Coefficient of temperature (9799)
t = Actual test condition temperature (O K)
tO = Standardized temperature (O K)
A = Coefficient of humidity (0.0175)
H = Actual relative humidity (%)
HO = Standardized relative humidity (%)


The standardized level (CO) is the concentration used to 
determine compliance with Sec. 3280.308(a).
    (5) The air chamber shall be inspected and recalibrated at least 
annually to insure its proper operation under test conditions.

[49 FR 32012, Aug. 9, 1984, as amended at 58 FR 55009, Oct. 25, 1993]