FORMALDEHYDE, SOLUTION, reacts violently with strong oxidizing agents (hydrogen peroxide, performic acid, perchloric acid in the presence of aniline, potassium permanganate, nitromethane). Reacts with bases (sodium hydroxide, potassium hydroxide, ammonia), and with nitrogen dioxide (explosive reaction around 180°C). Reacts with hydrochloric acid to form highly toxic bis(chloromethyl) ether. Polymerization reaction with phenol may develop sudden destructive pressure [Bretherick, 5th ed., 1995, p.168].
Toxic vapors such as carbon dioxide and carbon monoxide are generated during combustion. Explosion hazard: when aqueous formaldehyde solutions are heated above their flash points, a potential for explosion hazard exists. High formaldehyde concentration or methanol content lowers flash point. Reacts with nitrogen oxides at about 180; the reaction becomes explosive. Also reacts violently with perchloric acid-aniline, performic acid, nitromethane, magnesium carbonate, and hydrogen peroxide. When heated, irritant formaldehyde gas evolved from solution. The main products of decomposition are carbon monoxide and hydrogen. Metals such as platinum, copper, chromia, and alumina also catalyze the formation of methanol, methylformate, formic acid, carbon dioxide, and methane. Reacts with peroxide, nitrogen oxide, and performic acid causing explosions. Can react with hydrogen chloride or other inorganic chlorides to form bis-chloromethylether (BCME), a known carcinogen. Very reactive, combines readily with many substances, 40% solution is powerful reducing agent. Incompatible with amines, azo compounds, dithiocarbamates, alkali and alkaline earth metals, nitrides, nitro compounds, unsaturated aliphatics and sulfides, organic peroxides, oxidizing agents, and reducing agents. Aqueous solutions are unstable. Commercial formaldehyde-alcohol solutions are stable. Gas is stable in absence of water. Avoid oxidizing and alkaline materials. Hazardous polymerization may occur. Compound will polymerize with active organic materials such as phenol. Will polymerize violently in the presence of caustics and nitrides; (amines) exothermic reaction, (Azo compound) exothermic reaction giving off nitrogen gas, (caustics) heat generation and violent polymerization, (dithiocarbamates) formation of flammable gases and toxic fumes, formation of carbon disulfide may result, (alkali and alkaline earth metals) heat generation and formation of a flammable hydrogen gas.
Sources and uses of formaldehyde are numerous. Exposed
people are mainly health workers, cleaners, painters, met alworkers, but also photographers (color developers) and
carbonless copy paper users. Formaldehyde can induce
contact urticaria. Formaldehyde may be the cause of sen sitization to formaldehyde releasers: benzylhemiformal,
bromonitrodioxane, bromonitropropanediol (?), chloroal lylhexaminium chloride or Quaternium-15, diazolidinylu rea, dimethylol urea, dimethyloldimethylhydantoin or
DMDM hydantoin, hexamethylenetetramine or methe namine, imidazolidinylurea, monomethyloldimethylhy dantoin or MDM hydantoin, N-methylolchloracetamide,
paraformaldehyde and trihydroxyethylhexahydrotriazine
or Grotan BK.
Formaldehyde is used for the synthesis of many resins.
Some of them, such as formaldehyde-urea and melamine formaldehyde resins, can be used in textiles and second arily release free formaldehyde (see Chap. 40).
Other resins, such as p-tert-butylphenol formalde hyde resin or tosylamine formaldehyde resin, do not
It commonly contains added MeOH. Add KOH solution (1 mole KOH: 100 moles HCHO) to ~37% by weight aqueous formaldehyde solution (formalin), or evaporate to dryness, to give paraformaldehyde polymer which, after washing with water, is dried in a vacuum desiccator over P2O5 or H2SO4. Formaldehyde is regenerated by heating the paraformaldehyde to 120o under vacuum, or by decomposing it with barium peroxide. The monomer, a colourless flammable gas, is passed through a glass-wool filter cooled to -48o in a CaCl2/ice mixture to remove particles of polymer, then dried by passage over P2O5 and either condensed in a bulb immersed in liquid nitrogen or absorbed in ice-cold conductivity water. The gas or aqueous solutions have pungent suffocating odours, are LACHRYMATORY and suspected carcinogens, handle carefully. Formalin is a disinfectant and a preservative of dead animal and plant tissues. [Beilstein 1 IV 3017.]
Formaldehyde,HeHO, also known as methanol,formol,and methylene oxide,is a colorless gas at room temperature, In solution with water,it is a colorless poisonous liquid with a pungent odor. Formaldehyde is used in the manufacture of plastics and resins by reaction with phenols,urea, and melamine. It is used as a preservative,a disinfectant, and as a chemical intermediate,
Formaldehyde, also called formic aldehyde or methyl aldehyde, has extensive application. For instance, it is used as a tissue preservative or organic chemical reagent. Thus, formaldehyde is very common to the chemical industry. In fact, formaldehyde is an important chemical used widely by industry to manufacture building materials and numerous household products. It is also a by-product of combustion and certain other natural processes. It is present in substantial concentrations both indoors and outdoors. Formaldehyde is well known as a preservative in medical laboratories, as an embalming fluid, and as a steriliser. Its primary use is in the production of resins and as a chemical intermediate. Urea–formaldehyde (uf) and phenol–formaldehyde (pf) resins are used in foam insulations, as adhesives in the production of particle board and plywood, and in the treating of textiles. Sources of formaldehyde in the home include building materials, smoking, household products, and the use of unvented, fuel-burning appliances, like gas stoves or kerosene space heaters. Formaldehyde, by itself or in combination with other chemicals, serves a number of purposes in manufactured products.
Formaldehyde itself is a colourless gas, but it is more commonly purchased and used in aqueous solution (called formalin solution), with a maximum concentration of 40%. Formalin solutions often contain some amount of methanol as well. Both formaldehyde gas and solutions have a characteristic pungent, unpleasant odour.
The probable oral lethal dose for humans is 0.5-5 g/kg, or between 1 ounce and 1 pint for a 150 pound person. Acute -- below 1 ppm, odor perceptible to most. 2-3 ppm, mild tingling of eyes. 4-5 ppm, increased discomfort, mild lacrimation. 10 ppm, profuse lacrimation; can be withstood only for few minutes. 10-20 ppm, breathing difficult, cough, severe burning of nose and throat. 50-100 ppm, acute irritation of respiratory tract, very serious injury likely. Skin -- primary irritation from strong solutions, gas. Delayed -- sensitization dermatitis. Suspected carcinogen. Effects in women include menstrual disorders and secondary sterility. Solutions splashed in eyes have caused injuries ranging from severe, permanent corneal opacification and loss of vision to minor discomfort. In people sensitized to formaldehyde, late asthmatic reactions may be provoked by brief exposures at approximately 3 ppm.
Air & Water Reactions
The solution gives up formaldehyde vapors readily. These vapors are flammable over a wide vapor-air concentration range. Water soluble.
ChEBI: The simplest aldehyde.
Microbiocide, Fungicide, Bactericide; Soil
sterilent: Registered for use in the U.S. Not approved for
use in EU countries. Formaldehyde has found wide
industrial usage as a fungicide, germicide and in disinfectants. It is used most often in an aqueous solution
stabilized with methanol (formalin). It is also a pesticide
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