Formaldehyde is the smallest and simplest member of the aldehyde functional group family of the organic compounds. It occurs naturally as a colourless, but strongly pungent smelling gas. It possesses a highly flammable nature. Its vapours are very irritating to humans if inhaled. Formaldehyde is the common name of this compound but is more popular than its chemical synthetic name and IUPAC name, viz., methanal.
Its structure contains just the three simplest elements that all the organic compounds are made up of – namely carbon, hydrogen and oxygen. Its structural formula is HCHO. In condensed form, it may be written as CH2O. Its structure may be represented in the following manner:
Formaldehyde is widely used in multiple industries for a variety of purposes. Following is a comprehensive list of its various uses:
• In very minor diluted quantities, formaldehyde is used in the food industry as a preservative in a variety of packaged foodstuffs.
• Formaldehyde is used in the paint industry for the production of various materials such as exterior primers and the paints used for giving clear coats to the walls.
• Formaldehyde is also used in the cosmetic industry. It is not directly used as an ingredient in cosmetics. However, it may be released into the cosmetic products as one of the by-products from certain preservatives which are used during the manufacturing of those cosmetics. These preservatives include quaternium-15, diazolidinyl urea, DMDM hydantoin, imidazolidinyl urea, sodium hydroxymethylglycinate and 2-bromo-2-nitropropane-1, 3-diol. However, such cosmetic products used be used with very caution as formaldehyde might be harmful to the skin if exposed to it for a longer period of time or in higher concentrations. It may cause irritation in eyes and nose. It has also been proven to be carcinogenic in some studies.
• It is used as an antiseptic solution in very small concentrations. It possesses anti-bacterial and anti-fungal properties. It can even be used to treat parasite attack and warts infections. The mechanism of action by which formaldehyde acts as an anti-microbial agent has been studied by many researchers. The most common explanation given in such studies is that formaldehyde acts as an alkylating agent for the proteins and nucleic acids which constitute the basic DNA structure of the microbes, thereby leading to their denaturation due to which coagulation of proteins occur in the microbial DNA, leading to their death.
• It has been widely used as a chemical sterilizing agent since ancient times. It was also used as a disinfectant in mortuaries (a funeral home or a room where dead bodies are kept before post mortem or autopsy).
• Formaldehyde is one of the components used to make RDX.
• It is often mixed with automobile fuels such as petroleum and natural gas to improve their yields. It helps in making the vehicles more energy efficient and also saves fuels. Some users even claim that using formaldehyde technology in their vehicles make their vehicles feel lighter than the usual heavy fuels. It is also thus sometimes encouraged to use formaldehyde technology to help conserve the other natural resources which are more prone to depletion than this resource, which is freely available in our nature.
• In the dye industry, formaldehyde is used for the manufacturing of ink. Formaldehyde is used for the manufacture of certain pigments (such as formalin pigment, also known as acid hematin) which are used in printing inks.
• Formalydehyde is used in the polymer industry for the manufacture of certain resins which are used in the production of wooden carpentry products such as cabins, chairs, tables and other furniture materials and moldings, wooden flooring, shelves, counters and other related household materials. The resins made from formaldehyde in the wood industry are known to be of very superior quality and tensile strength and cause minimal wastage of resources, Also formaldehyde being a natural source is better than other chemical and synthetic materials used for the same purpose, and hence is a more sustainable source. The resins produced from formaldehyde for such purposes include urea formaldehyde resin (produced by a reaction between formaldehyde and urea), melamine resin(produced by a reaction between formaldehyde and melamine), and phenol formaldehyde resin(produced by a reaction between formaldehyde and phenol).
• The melamine formaldehyde resins produced by the reaction between formaldehyde and melamine are probably one of the most durable formaldehyde-based resins. It is water resistant and is used for various purposes such as making rain resistant house top laminates, water repellent flooring laminates and water clearing material coats for vehicles.
• Formaldehyde has been conventionally used for the preparation of certain vaccines and their sterilization. It has been widely used in the preparation of influenza vaccine, since it itself also acts as an anti-viral agent, thereby causing cumulative and synergistic effect along with the active component of the vaccine. Also, it has been used for the inactivation of certain bacterial endotoxins products which are used as an inoculation for the treatment of certain bacterial infections.
• Formaldehyde was, in ancient times, used for the treatment of certain urinary tract infections, probably due to its anti-bacterial properties. Nowadays, a chemical substance derived from formaldehyde, named methenamine is used for the same purpose. It is also a component of certain topical ointments used to treat fungal infections. However, FDA has limited its use to certain proportions and should not be used beyond those proportions as it may be toxic and produce harmful side effects on the skin. Also, always consult your dermatologist before starting the use of such products as these should not be used without proper prescription and medical supervision.
• Formaldehyde is one of the raw materials used in the sanitary products industry for the manufacture of certain sanitary products such as towels, paper napkins, facial wipes, tissue papers, sanitizers and other related stuff.
• Formalin, a 37% solution of formaldehyde, is a known effective disinfectant used for disinfecting a variety of things. It is even used for the treatment of certain skin infections. It is also used as an anti-perspirant to prevent excessive sweating in areas such as feet (so as to prevent fungal infections).
• Formaldehyde acts as a building block of the polymers which are used as high-quality bonding agents such as adhesives. It has excellent binding properties. The glues and resins prepared by using formaldehyde are highly effective. It is also an economical option as compared to other synthetic adhesives as it is freely and cheaply available.
• The resins prepared by the reaction between formaldehyde and phenol are used for the production of brake linings or pads for vehicles. These resins are highly resistant to fire as they can bear very high temperatures without getting degraded or decomposed.
• Formaldehyde is a common ingredient in personal care products and fast moving consumer goods and hence is widely used in the FMCG industry during the manufacture of various products.
• Formaldehyde constitutes almost 90% portion of our upper atmosphere. In our lower atmosphere, if present in some quantities, it is broken down into smaller chemicals such as carbon dioxide, in presence of sunlight (due to the heat energy which is sufficient to cause its degradation and decomposition). In fact, it is one of the main components of the atmosphere of the planet Venus. The clouds in the atmosphere of Venus are formed by polymerized formaldehyde.
• Formaldehyde is one of the intermediates produced during the combustion of methane gas before it finally converts to carbon dioxide. It is also one of the main components produced and released into the air when any organic matter burns e.g., the burning of tree woods during forest fires, the exhaust producing due to the burning of fuel in automobiles and vehicles and smoke produced by tobacco users.
• Formaldehyde is also used in the textile industry. In addition to the preparation of dyes and pigments, it also acts as a binding agent and helps in the binding of those pigments to the fibers of the cloths. The cloths made from formaldehyde binding pigments are less prone to colour fading after washing as compared to other chemical and synthetic adhesives or binders used in the textile industry. Resins made from formaldehyde are also used in the textile industry to give wrinkle free properties to the fibers. The clothes prepared by using formaldehyde-based resins are lesser prone to the formation of wrinkles and creases even when folded or pressed.
• In biology laboratories, a 4% aqueous solution of formaldehyde in water is used for the preservation and storage of biological specimens of human, animals and insects. It protects these samples because of its polymeric property by which it forms cross-linking bonds with the nitrogen atoms (via forming –CH2 linkages) present in the primary amino acids (present in the primary straight chain structures of the protein chains) present in the DNA structure of biological samples.