Formaldehyde is the first member of the aldehyde series. It is present in green leaves of plants where its presence is supposed to be due to the reaction of \(CO_2\) with water in the presence of sunlight and chlorophyll. Commercially, formaldehyde is obtained by the controlled oxidation of methane in the presence of molybdenum oxide \((MoO)\) acting as a catalyst. Formaldehyde is a constituent of a number of polymers also called resins. These are non volatile solids or semi solids which are obtained directly from certain plants and can be synthesized in the laboratory.

How is formalin useful? 

Formalin is used as germicide, disinfectant and antiseptic

The correct answer is option 2. Formalin is used as germicide, disinfectant and antiseptic.

Formalin is a solution of formaldehyde gas in water and has several practical uses due to its chemical properties. Here's a detailed explanation of its applications:

Uses of Formalin

Germicide, Disinfectant, and Antiseptic:

Germicide: A germicide is a substance that destroys or inhibits the growth of microorganisms. Formalin acts as a broad-spectrum germicide because it effectively kills bacteria, fungi, and viruses. This property makes it valuable in medical settings and laboratories to maintain sterility and prevent contamination. Used in disinfecting laboratory equipment, surfaces, and medical instruments.

Disinfectant: A disinfectant is a chemical agent used to eliminate or reduce harmful microorganisms on surfaces. Formalin is a strong disinfectant that can be used to sanitize environments where pathogens are a concern. Commonly used in hospitals, clinics, and industrial settings to disinfect surfaces and equipment. It is also used in the water treatment process to ensure water is free from harmful microorganisms.

Antiseptic: An antiseptic is a substance used to prevent infection by killing or inhibiting the growth of microorganisms on living tissue. Formalin, in diluted forms, can act as an antiseptic, although it is more commonly used in higher concentrations as a disinfectant. Used in some medical settings for treating minor wounds and cuts to prevent infection, although its use is less common compared to other antiseptics.

Preservation: Preservation refers to the process of maintaining biological samples in a state that prevents decomposition and decay. Formalin prevents the breakdown of biological tissues by cross-linking proteins, thereby preserving them for long periods. Used in embalming to preserve human remains and in laboratories to preserve tissue samples for histopathological examination.

Medical and Clinical Uses: Preservation in medical contexts involves maintaining tissue samples and specimens for research and diagnostic purposes. Formalin’s ability to preserve tissue structure makes it invaluable for medical research and pathology. Used to fix and preserve tissue samples in clinical laboratories.

Industrial Applications:

Resins and Plastics: Resins are synthetic substances used in various industrial applications. Formalin is used in the production of phenolic resins and urea-formaldehyde resins, which are key components in many industrial products. Phenolic resins are used in the manufacture of durable goods such as laminates, and urea-formaldehyde resins are used in adhesives and particleboard.

Textiles and Paper: Textile and paper industries use chemicals to treat and strengthen materials. Formalin is used to treat fabrics to enhance their durability and to improve the strength of paper products. In textiles, it helps in wrinkle resistance, and in paper production, it increases paper strength.

Not Used For:

Antibiotics: Formalin is not an antibiotic. Antibiotics are specifically designed to target and kill bacteria or inhibit their growth, while formalin acts as a general disinfectant and preservative.

Insecticides: Formalin is not used as an insecticide. Insecticides are chemicals designed to repel or kill insects, and formalin does not have this specific function.

Antacids: Formalin is not used as an antacid. Antacids neutralize stomach acid to relieve heartburn, and formalin is not suitable for this purpose.

Conclusion: Formalin's primary uses are as a germicide, disinfectant, and antiseptic, making it valuable in healthcare, laboratory settings, and industrial applications. It plays a crucial role in preserving biological samples and disinfecting environments, but it is not used for antibiotics, insecticides, or antacid