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Urea-formaldehyde (UF), also known as urea-methanal, so named for its common synthesis pathway and overall structure, [1] is a nontransparent thermosetting resin or polymer. It is produced from urea and formaldehyde. These resins are used in adhesives, plywood, particle board, medium-density fibreboard (MDF), and molded objects.
The Biden administration has officially determined the chemical formaldehyde poses an “unreasonable” risk to human health and should be regulated. The Environmental Protection Agency (EPA ...
The structure of the molecule of urea is O=C(−NH 2) 2.The urea molecule is planar when in a solid crystal because of sp 2 hybridization of the N orbitals. [8] [9] It is non-planar with C 2 symmetry when in the gas phase [10] or in aqueous solution, [9] with C–N–H and H–N–H bond angles that are intermediate between the trigonal planar angle of 120° and the tetrahedral angle of 109.5°.
Formaldehyde is a common precursor to more complex compounds and materials. In approximate order of decreasing consumption, products generated from formaldehyde include urea formaldehyde resin, melamine resin, phenol formaldehyde resin, polyoxymethylene plastics, 1,4-butanediol, and methylene diphenyl diisocyanate. [40]
The energy consumption and greenhouse gas emissions associated with the production of Urea-formaldehyde are lower than those of Phenol formaldehyde adhesives. But Urea-formaldehyde adhesive is judged to have a nearly 50% higher life cycle impact than Phenol formaldehyde mainly because of acid based emissions during its production process. [15] [13]
Despite genuine concerns, formaldehyde is a naturally occurring substance, of which human beings produce approximately 1.5 oz a day as a normal part of a healthy metabolism. Formaldehyde also occurs naturally in many fruits, such as bananas, apples, and carrots, and does not bioaccumulate in either plants or animals. [4]
Compounds baring N-methylol groups, such as dimethylol ethylene urea and the related Dimethylol dihydroxyethylene urea (DMDHEU), are commonly used for the treatments because of their relatively low costs; however, they produce free formaldehyde, [10] which has been identified as a potential human carcinogen, and it can also cause harmful ...
Formaldehyde is dangerous to human health. [8] [9] In 2011, the US National Toxicology Program described formaldehyde as "known to be a human carcinogen". [10] [11] [12] The danger of formaldehyde is a major reason for the development of formaldehyde releasers which release formaldehyde slowly at lower levels. [13]