EVALUATION OF METHODS FOR ESTIMATING FORMALDEHYDE RELEASED FROM RESIN-CONTAINING PAPER AND WOOD PRODUCT DUSTS

Epidemiology studies have suggested that exposures to formaldehyde in combination with dust particles in workplace atmospheres may be linked to increased risk of some cancers. Information on the amounts of formaldehyde associated with different sized particles is lacking as well as appropriate methodology for assessing the possible significance of this mode of exposure. This prompted studies to evaluate methods for estimating amounts of formaldehyde that may be released from inhaled particles of paper and wood product dust containing formaldehyde-based resins. The relationship between quantities of released formaldehyde and particle soaking conditions were assessed. The chromotropic acid, MBTH, and acetylacetone analysis procedures were examined for their appropriateness in measuring released formaldehyde. Use of the chromotropic acid procedure for this purpose indicated formaldehyde levels for wood product dusts that were approximately 10 to 14 times higher than those determined by the MBTH and acetylacetone methods. The findings indicated that soaking dust particles in deionized water at 35°C for 6 hr, filtering to remove the particles, and measuring the released formaldehyde present in the water by a colorimetric procedure that used acetylacetone reagent would provide reliable estimates of releasable formaldehyde.