formaldehyde

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formaldehyde

(fôrmăl`dəhīd'), HCHO, the simplest aldehydealdehyde
[alcohol + New Lat. dehydrogenatus=dehydrogenated], any of a class of organic compounds that contain the carbonyl group, , and in which the carbonyl group is bonded to at least one hydrogen; the general formula for an aldehyde is RCHO, where R is hydrogen
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. It melts at −92°C;, boils at −21°C;, and is soluble in water, alcohol, and ether; at STPSTP
or standard temperature and pressure,
standard conditions for measurement of the properties of matter. The standard temperature is the freezing point of pure water, 0°C; or 273.15°K;.
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, it is a flammable, poisonous, colorless gas with a suffocating odor. Formaldehyde is used in the preparation of dyes, in the production of BakeliteBakelite
[for its inventor, L. H. Baekeland], synthetic thermosetting resin. It has been widely used both alone, to form whole objects, and in combination with other materials, as a laminate or a surface coating.
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 and other plastics and synthetic resins, and for several other purposes, such as in glues and adhesives used to produce laminated and composite woods and wood products. Pure gaseous formaldehyde is uncommon, since it readily polymerizes into paraformaldehyde, a white crystalline solid. Paraformaldehyde in the form of candles has been used for fumigating rooms, since it yields formaldehyde when heated. Formalin is a 40% by volume solution of formaldehyde in water, usually with a small amount of methanol (methyl alcohol) added to prevent polymerization; it is used as an antiseptic, disinfectant, and preservative for biological materials. Formaldehyde is prepared commercially by passing methanol vapor mixed with air over a catalyst, e.g., hot copper, to cause oxidation of the methanol; it is also prepared by the oxidation of natural gas. It forms formic acid when it is oxidized. The IUPAC name for formaldehyde is methanal.
The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved. www.cc.columbia.edu/cu/cup/

Formaldehyde

A gas used widely in production of adhesives, plastics, preservatives, and fabric treatments and commonly emitted by indoor materials that are made with its compounds. It is highly irritating if inhaled and is now listed as a probable human carcinogen.
Illustrated Dictionary of Architecture Copyright © 2012, 2002, 1998 by The McGraw-Hill Companies, Inc. All rights reserved
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Formaldehyde

 

(also methanal), CH2O, the first member of the homologous series of aliphatic aldehydes. A colorless gas with a pungent odor, formaldehyde is freely soluble in water and alcohol. It has a boiling point of – 19°C.

Formaldehyde is prepared commercially by the oxidation of methanol (methyl alcohol) or methane with atmospheric oxygen. Because it polymerizes readily, especially at temperatures up to 100°C, it is stored, transported, and used mainly in the form of Formalin or in the form of solid low-molecular polymers— trioxane and paraformaldehyde.

Formaldehyde is highly reactive. Many of its reactions form the basis of numerous commercial methods for the preparation of important products. For example, on interaction with ammonia, formaldehyde yields urotropine (hexamethylenetetramine); with urea, urea-formaldehyde resins; with melamine, melamine resins; with phenols, phenol-formaldehyde resins; with phenol-sul-fonic and napthalene sulfonic acids, tanning agents; and with ket-ene, beta-propiolactone. Formaldehyde is used in the manufacture of polyvinyl formal, isoprene, pentaerythritol, pharmaceuticals, and dyes. It is also used in the tanning of leather and as a disinfectant and deodorizing agent. The polymerization of formaldehyde yields polyformaldehyde.

Formaldehyde is toxic; its maximum tolerable concentration in the air is 0.001 mg/liter.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

formaldehyde

[fȯr′mal·də‚hīd]
(organic chemistry)
HCHO The simplest aldehyde; a gas at room temperature, and a poisonous, clear, colorless liquid solution with pungent odor; used to make synthetic resins by reaction with phenols, urea, and melamine, as a chemical intermediate, as an embalming fluid, and as a disinfectant. Also known as formol; methanal; methylene oxide.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

formaldehyde, methylene oxide

A colorless, pungent, volatile liquid, readily soluble in water, widely used in the manufacture of plastics and resins and as a disinfectant.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.

formaldehyde

a colourless poisonous irritating gas with a pungent characteristic odour, made by the oxidation of methanol and used as formalin and in the manufacture of synthetic resins. Formula: HCHO
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
References in periodicals archive ?
Therefore, a closed loop of HCHO removal can be fulfilled with an excellent economic and environmental viability.
That study showed that the chemisorption was much higher than activated carbon and was around 10 mg/g with an HCHO concentration between 0.1-1 ppm, and 100 mg/g with an HCHO concentration at about 30 ppm.
Basados en las reacciones de remocion (sumideros) dadas en la Tabla V, se estima que el tiempo de vida fotoquimico del HCHO es de ~3h.
LEV 0.300/0.430 7.0/10.3 1.0/1.5 --/0.12 ULEV 0.180/0.257 7.0/10.3 1.0/1.5 --/0.06 SULEV 0.090/0.130 3.5/5.2 0.5/0.7 --/0.06 Vehicle type HCHO g/mile 50/120K MDV4 0.028/-- 8501-10.000 lbs.
The results showed that CoS/Ti[O.sub.2] had the best photocatalytic activity in the [H.sub.2] and HCHO production reactions under 300 W Xe lamp irradiation.
It is seen that the peak current increases linearly with the concentrations of HCHO from 1 to 10 ppm.
As mentioned earlier, the variability of manufactured products (and therefore variability in HCHO emissions) varies significantly across the wood composites panel industry given the differences in manufacturing technologies, diversity of feedstocks and chemical additives, and age of facilities.
Quantified HCHO was associated with neurologic symptoms (difficulty concentrating POR 1.47; 95% CI: 1.02, 2.13).
The performance of five typical portable air cleaners for residences available on the Japanese market, shown in Table 1, was evaluated; HCHO was chosen as the main challenge gas because of its carcinogenicity.
Las concentraciones de HCHO, HCOOH y C[H.sub.3]COOH medidas en las lluvias individuales recolectadas en Parupa, durante el periodo set 99 a dic 2000, no muestran ninguna tendencia estacional significativa, contrastando con lo observado en la region norte de Venezuela, en donde se observan altas concentraciones de HCHO y HCOOH durante el periodo de transicion entre la epoca seca y la de lluvia (Sanhueza et al., 1991).
The TG-1900KBP Formaldehyde (HCHO) gas monitor is a direct reading, compact instrument with digital display that uses a patented gas membrane galvanic sensor which never needs to be replaced.