Are there special criteria for formaldehyde and acetaldehyde?
CRELs are developed without concern for practical issues. The CREL for formaldehyde (3 µg/m3) is approximately the same as outdoor formaldehyde concentrations in urban areas and almost always is exceeded indoors due to the many sources of this chemical. Consequently, OEHHA has developed an 8-hour indoor REL for formaldehyde based on its acute REL. This value is 33 µg/m3 (27 parts-per-billion), with the limit for individual products set at one-half that value. Acetaldehyde is another chemical with a very low CREL (9 µg/m3) that is found in ambient outdoor air. Similar to formaldehyde, one-half the CREL for this chemical is near its detection limit. Thus, the California Department of Health Services recommends using the full CREL as the pass/fail level for determining the acceptability of building products (See CA/DHS/EHLB/R-174, Addendum 2004-1, October 19, 2004).
