Insulation products, release formaldehyde

Unwashed new clothing samples (Table IIC), fiberglass insulation products with formaldehyde resins (Table IID), paper products (Table HE), fabrics (cotton, nylon, olefin, and blended) (Table HF), and carpets (Table HG), had substantially 3 to > 100 fold) lower formaldehyde release rate coefficients, as measured by this method, than did pressed wood products or urea formaldehyde foams (1, 15). 

Most products tested released only small amounts of formaldehyde. Only some pressed wood and urea formaldehyde foam insulation products released higher amounts of formaldehyde. Products tested in both ventilated chambers and unventilated desiccators released similar amounts of formaldehyde. Formaldehyde released by particle board was reabsorbed by the second product tested in a dynamic chamber. In a house this reabsorption might lower the room level of formaldehyde. 

The relative ranking for each type of product on the basis of rate of release of formaldehyde per unit surface area was pressed wood products z formaldehyde foam clothes z insulation products z paper products > fabric > carpet. Considering the surface area of each type of product likely to be present in houses and the relative release rate coefficients. 

In 1993, worldwide consumption of phenoHc resins exceeded 3 x 10 t slightly less than half of the total volume was produced in the United States (73). The largest-volume appHcation is in plywood adhesives, an area that accounts for ca 49% of U.S. consumption (Table 11). During the early 1980s, the volume of this apphcation more than doubled as mills converted from urea—formaldehyde (UF) to phenol—formaldehyde adhesives because of the release of formaldehyde from UF products. Other wood bonding applications account for another 15% of the volume. The next largest-volume application is insulation material at 12%. 

Formaldehyde and other aldehydes are receiving increasing attention both as toxic substances and as promoters in the photochemical formation of ozone in the atmosphere. They are released into residential buildings from plywood and particle board, insulation, combustion appliances, tobacco smoke, and various consumer products. Aldehydes are released into the atmosphere in the exhaust of motor vehicles and other equipment in which hydrocarbon fuels are incompletely burned. A sensitive method for analyzing aldehydes and ketones is based on the sorption of these compounds to an SPE sorbent and their subsequent reaction with 2,4-dinitrophenylhydrazine (DNPH) on the sorbent. They are then analyzed as their hydrazones by HPLC (Fig. 7.9). A gradient analysis by HPLC may separate as many as 17 components with detection by ultraviolet (UV) light. 

Formaldehyde (CH2O) release was measured for seven types of consumer products pressed wood, urea formaldehyde foam materials, clothes, insulation, paper, fabric, and carpet. A modified Japanese Industrial Standard (JIS) desiccator test was used to measure release rate coefficients and to rank 53 products. Ten pressed wood products and five urea formaldehyde foam products showed the highest CH2O releases (1-34 mg m 2.day"b The remainder, representing all product types, had lower releases ranging from 680 yg m 2.day to nondetectable levels. In other studies, CH2O release was measured in a ventilated chamber for single samples of particle board, plywood, insulation, and carpet. 

After testing each of the four individual products, three pairs of products were tested. Formaldehyde release when multiple products were in the same chamber was measured as above. The three pairs tested were particle board/plywood, particle board/insulation, and particle board/carpet. 

Formaldehyde release rates were measured using multiple consumer products in a dynamic chamber. Particle board and plywood had high formaldehyde specific release rate coefficients. Combined plywood and particle board had a release rate 68% of the sum of the two products and 91% of the particle board release (Table V). When particle board was combined with insulation, the combined release rate was 71% of the sum of the separate release rates and 73% of the particle board release. Particle board and carpet combinations gave similar results. 

A good correlation was noted between release rate coefficients at loadings of 1.4-2.8 m2 of product surface area/m of chamber volume and formaldehyde extractable into toluene (Table V r = 0.999 p = < 0.001). Total extractable formaldehyde was quite low in both carpet and fiberglass insulation (0.5-1.6 mg/100 g of material) relative to that in plywood or particle board (22-55 mg/100 g of material) (Table V) (12). 

When particle board was paired with plywood, insulation, or carpet and tested in a dynamic chamber, the formaldehyde released was 60% of the sum of that released when each product was tested alone. Similar results have been observed by others (19). Approximately half of this reduction is related to the increase in chamber loading noted in Table IV (14-17). In fact, the release of formaldehyde when these products were combined with particle board was less than that released by particle board alone. These results suggest that formaldehyde from the high-emitting particle board moved into the lower emitting product. If this is the case, it is highly likely that the water present in the second product actually absorbed some formaldehyde given off by the particle board since formaldehyde tends to move into the water phase of the... 

Formaldehyde is also released from aminoplasts and their derivatives, such as urea-formaldehyde foam insulation (UFFI), wood adhesives, and textile finishing agents. It is this supplemental, industrial source of formaldehyde that has become the subject of risk analysis. Should we allow products that serve our daily comfort to alter our environment by releasing an irritating vapor with a pungent odor ... 

---