Environmental factors, formaldehyde

Once in the soil solution, urea—formaldehyde reaction products are converted to plant available nitrogen through either microbial decomposition or hydrolysis. Microbial decomposition is the primary mechanism. The carbon in the methylene urea polymers is the site of microbial activity. Environmental factors that affect soil microbial activity also affect the nitrogen availabiUty of UF products. These factors include soil temperature, moisture, pH, and aeration or oxygen availabiUty. 

Apart from the environmental factors, chemical compounds also induce cross-linking of gelatin. Supporting this is the mechanism in Fig. 5, which highlights the role of external aldehydes. Among the low molecular weight aldehydes, formaldehyde is most important as it is released in dosage forms from plasticizers and preservatives, fats, and polyethylenated... 

In reviewing the fate of formaldehyde in the environment, it should be noted that the environmental factors that influence the bioavailability to humans of formaldehyde from contaminated air, water, or plant material have not been studied. 

The need for control of formaldehyde emission from UF-bonded wood products has been recognized since Wittmann (4) reported in 1962 that extensive use of particleboard in furniture and building envelopes can cause indoor formaldehyde concentrations exceeding occupational threshold levels. However, it proved to be difficult to define the problem because formaldehyde emission from finished products was not regularly measured, and the correlation between emission rate and the environmental factors were not yet well established. 

Warm-box emissions Compared to the hot-box process, the emissions are significantly lower. The emissions do not contain phenol or ammonia, and also formaldehyde emissions are diminished by a factor of 4. As Ae pattern temperature is also lower compared to the one used for the hot-box process, the woiking conditions are also improved. The environmental impact is considered to be relatively low... 

Schwope AD, Costas PP, Mond CR, Nolen RL, Conoley M, Garcia DB, Walters DB, Prokopetz AT (1988) Gloves for protection from aqueous formaldehyde permeation resistance and human factors analysis. Appl Ind Hyg 3 167-176 Sessink PJM, van de Kerkhof, MC A, Anzion RB, Bos RP (1994) Environmental contamination and assessment of exposure to antineoplastic agents by determination of Cyclophosphamide in urine of exposed pharmacy technicians Is skin absorption an important exposure route Arch Environ Health 4 165-169 Van Ketle WG, Tan-Lim HN (1975) Contact dermatitis from ethanol. Contact Dermatitis 1 7-10... 

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