Formaldehyde formaldehyde detection
What is formaldehyde formaldehyde
Formaldehyde, also known as formaldehyde, is a colorless gas with a strong pungent odor. Easily soluble in water, alcohol and ether. It is gaseous at room temperature and often appears in the form of aqueous solution.
Molecular formula of formaldehyde: CHO; simplified structural formula: HCHO; molecular weight: 30.03; CAS registration number: 50-00-0; EINECS registration number: 200-001-8; melting point -92°C; boiling point -21°C, density in liquid state It is 0.815 g/3 cm (20°C) and is easily soluble in water and ethanol. A 35-40% formaldehyde aqueous solution is called formalin.
There is an aldehyde group in the formaldehyde molecule that undergoes a polycondensation reaction to obtain phenolic resin (bakelite).
Formaldehyde is an important organic raw material, mainly used in the plastic industry (such as phenolic resin, urea-formaldehyde plastic-electric jade), synthetic fibers (such as synthetic vinylon-polyvinyl formal), leather industry, medicine, dyes, etc. Formaldehyde has bactericidal and antiseptic capabilities and can be used to soak biological specimens. Its dilute solution (0.1-0.5%) can be used to soak seeds and disinfect them in agriculture.
Formaldehyde’s properties, harm to the human body and its sources
Formaldehyde (formaldehyde) is a pure poison that can bind to proteins. Inhaling high concentrations of formaldehyde can cause severe respiratory tract irritation and edema, eye irritation, headache, and bronchial asthma . Direct skin contact with formaldehyde can cause dermatitis, stains, and necrosis. Regular inhalation of formaldehyde can cause chronic poisoning, mucosal congestion, skin irritation, allergic dermatitis, nail keratosis and fragility, nail bed fingertip pain, etc. Systemic symptoms include headache, fatigue, poor appetite, palpitations, insomnia, weight loss, and autonomic nervous system disorders.
Various artificial boards (particleboard, fiberboard, plywood, etc.) can contain formaldehyde due to the use of adhesives. Adhesives are used in the production of new furniture and the decorative laying of walls and floors . Wherever adhesives are used in large quantities, there will always be formaldehyde released. In addition, some chemical fiber carpets, paints and coatings also contain a certain amount of formaldehyde.
Formaldehyde can also come from cosmetics. Cosmetics, detergents, pesticides, disinfectants, preservatives, printing inks, paper, textile fibers and other chemical and light industrial products. The uses and applications of formaldehyde formaldehyde
Formaldehyde (formaldehyde) is a popular chemical product with a wide range of uses, simple production technology, and sufficient supply of raw materials. It is mainly used in: synthetic resins, surfactants, plastics, rubber, leather, papermaking, dyes, pharmaceuticals, pesticides, photographic films, and explosives , building materials, as well as disinfection, fumigation and anti-corrosion processes, formaldehyde is used. It can be said that formaldehyde is a generalist in the chemical industry, but the use of anything must have a limit and a standard. Once the use exceeds the standards and limits, It will bring disadvantages.
The key substances derived from it mainly include polyformaldehyde, polyformaldehyde, phenolic resin, urea-formaldehyde resin, amino resin, methenamine products and polyols, etc.
Application of formaldehyde formaldehyde
1), wood industry
It is used to produce urea-formaldehyde resin and phenolic resin. It is produced by mixing formaldehyde and urea in a certain molar ratio.
2), Textile industry
The use of formaldehyde is involved in the resin finishing process of clothing. In the production of clothing fabrics, in order to achieve anti-wrinkle, anti-shrinkage, flame retardant and other functions, or to maintain the durability of printing and dyeing, or to improve the feel, formaldehyde needs to be added to the additives. At present, formaldehyde printing and dyeing auxiliaries are mostly used in pure cotton textiles, because pure cotton textiles are prone to wrinkles, and the use of formaldehyde-containing auxiliaries can improve the stiffness of cotton fabrics. Textiles containing formaldehyde will gradually release free formaldehyde when people wear and use it, causing respiratory inflammation and skin inflammation through human respiratory tract and skin contact, and can also cause eye irritation. Formaldehyde can cause allergies and can also induce cancer. Manufacturers use dyeing auxiliaries containing formaldehyde. In particular, some manufacturers use cheap auxiliaries with extremely high formaldehyde content in order to reduce costs, which is very harmful to the human body.
3), anti-corrosion solution
Formaldehyde is a substance released by the decomposition of formaldehyde and sodium bisulfite above 60°C. It is colorless, has a pungent smell, and is easily soluble in water.
35% to 40% formaldehyde aqueous solution, commonly known as formalin, has antiseptic and sterilizing properties and can be used to soak biological specimens, sterilize seeds, etc.
The main reason why formaldehyde has antiseptic and bactericidal properties is that the amino groups on the proteins that make up organisms (including bacteria) can react with formaldehyde.
4), food industry
Utilize the antiseptic properties of formaldehyde and add it to foods that are difficult to store, such as aquatic products.
Restrictions on formaldehyde
Textile auxiliaries that cause the formaldehyde content of textiles that are in direct contact with the skin to exceed 30 ppm and that cause the formaldehyde content of all other textiles to exceed 300 ppm cannot be used, such as wool protective agents, color fixing agents, cross-linking agents, and adhesives that contain excessive amounts of formaldehyde. wait.
Limit the amount of free and partially hydrolyzable formaldehyde in textile dyes to ensure that the amount of free and partially hydrolyzable formaldehyde on fabrics does not exceed 30 ppm for textiles that are in direct contact with the skin, but not for all other textiles. More than 300ppm.
Heavy metal salts (except iron) or formaldehyde cannot be used as color removers or fading agents in textiles.
In addition, the following standards also impose corresponding restrictions on materials that may contain formaldehyde:
Toy safety requirements EN71
Eco-textile requirements Oko-Tex 100; Eco-Textile
German food hygiene law LFGB
Requirements for formaldehyde release in Materials in Direct Contact with Food 2004/1935
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Formaldehyde Common Formaldehyde Testing Standards
EN717-1 Formaldehyde content detection in all wood products
EN717-2 Formaldehyde content detection in all wood products
EN717-3 Formaldehyde content detection in uncoated wood products
EN71-9 Formaldehyde content detection in toy materials
GB18580 Detection of formaldehyde content in man-made boards such as density boards, fiberboards, particleboards, plywood, blockboards, and decorative panels
GB17657 Formaldehyde content detection in artificial boards and decorative artificial boards
GB18584 Formaldehyde content detection in artificial boards
GB18582 Formaldehyde content detection in indoor wall coatings
GB18583 Formaldehyde content detection in adhesives for interior decoration
ASTM D5582 Wood products-containing urea-formaldehyde resin adhesives, including formaldehyde content detection in plywood, hardwood board, particle board, medium density fiberboard
ASTM E1333 Wood products-Containing urea-formaldehyde resin adhesives, including detection of formaldehyde content in plywood, hardwood boards, particleboards, and medium-density fiberboards
ASTM D6007 Formaldehyde content detection in wood products
JIS A 5905 Formaldehyde content detection in fiberboard
JIS A 1460 Formaldehyde content detection in building materials panels
JIS A 5908 Formaldehyde content detection in particle board
AS/NZS 4266.16 Formaldehyde content detection in artificial panels
BS EN 14184 Formaldehyde content detection in textiles
EN120 Formaldehyde content detection in wood products
AATCC 112, BS6806, GB/T 2912, DIN53315, SFS 4996, LAW 112, JIS L-1041, JIS L-1096, AATCC 94 Formaldehyde content detection in textiles
EN645, EN647, EN1541 Formaldehyde content detection in paper