Zinc Oxide Uses

Zinc oxide is an inorganic compound that occurs in the Earth's crust as a mineral, known as zincite. However, zinc oxide is also synthesized artificially in order to meet most of its commercial demand.

The chemical formula of zinc oxide is ZnO. It is a white, powdery substance that is insoluble in water and alcohol, but soluble in most acids, including hydrochloric acid (HCl).

The mineral zincite can appear slightly yellowish or reddish in color, due to the presence of manganese and other impurities. Zinc oxide is known to react strongly with aluminum and magnesium powder.

Another interesting property of this inorganic compound is that it can absorb ultraviolet radiation. It is also known for its high thermal conductivity and antibacterial properties.

Zinc oxide has been in use for medicinal purposes for a long time. In fact, it was mentioned in the ancient Indian medical text, the 'Charaka Samhita'. Even the Greek physician Dioscorides mentioned the use of zinc oxide for medicinal purposes. Today, this compound has found a myriad of applications in both, the industrial and pharmaceutical sectors.

✧ Zinc oxide is used as an additive in a wide range of materials and products. It is used in rubber manufacturing, mainly in the vulcanization of rubber. Vulcanization of rubber is a chemical process that helps improve the strength and elasticity of rubber. Vulcanized or cured rubber is mostly used in manufacturing tires and shoe soles.

✧ This compound is also used for concrete manufacturing. It helps make concrete more water resistant, besides improving the processing time required.

✧ Zinc oxide is a component in cigarette filter. A cigarette filter is used to remove certain harmful compounds, such as hydrogen cyanide and hydrogen sulfide gases from tobacco smoke, without altering its flavor.

✧ It is a very common ingredient in ceramic glazes, including tiles. It lowers the melting point of the glazes, and changes their optical properties besides improving elasticity. Zinc oxide is also used in manufacturing photochromic lenses and heat-resistant glass and cookware.

✧ Zinc dialkyldithiophosphates (ZDDP), which is used in lubricating oil is derived from zinc oxide. The ZDDP compounds are formed when zinc oxide reacts with dialkyl dithiophosphoric acid intermediate. These compounds help inhibit corrosion, which is why they are used in lubricating oil.

✧ This inorganic compound is also used as a pigment in paints due to its opacity. Zinc phosphate pigments are used in anti-corrosive paints. They are formed when zinc oxide reacts with phosphoric acid. Paints containing zinc oxide have also been used as anticorrosive coatings for metals, especially for galvanized iron.

✧ It is highly valued in the plastic industry, as it imparts heat-resistant properties to acrylic composites and increases their mechanical strength. Zinc borate, which is widely found in plastics, is formed when zinc oxide reacts with boric acid.

✧ This compound is also used in the formation and cure of epoxide resin. It can impart fire-resistant properties to nylon fibers and moldings.

✧ It can prevent the growth of fungi, due to which it is used in many applications. The antistatic, fungistatic, and emulsion stability properties of vinyl polymers can be attributed to zinc oxide. It is also added to fungicides in order to make them more effective in preventing the growth of fungus.

✧ Apart from this, this compound and its derivatives can be found in fire retardants, batteries, fuel cells, adhesive, sealants, varistors, and cement.

✧ Zinc oxide has antibacterial properties, for which it is extensively used in treating several skin conditions. It is topically used to provide relief in skin irritation, minor burns, and cuts. It can be used for dry and chapped skin as well.

✧ It is the most commonly used product for treating and preventing diaper rash. It basically forms a protective barrier between the skin and the diaper, and thus help prevent any rash.

✧ It is added to baby powder, anti-dandruff shampoos, antiseptic creams, and surgical tapes due to its medicinal properties. Along with iron oxide, it is used to make calamine lotion.

✧ This compound is mixed with eugenol to form zinc oxide eugenol, which is used in dentistry for restorative and prosthodontic applications.

✧ The ability to treat itching and skin irritation has made this compound an important ingredient in many rectal suppositories, that are used to relieve irritation and discomfort caused by hemorrhoids.

✧ This compound is also a source of the mineral nutrient zinc, which is required for carrying out a wide range of vital biochemical reactions in the body. So, It is added to dietary or vitamin supplements.

As a food additive, zinc oxide can be found in vitamin and mineral-fortified breakfast cereals. Due to its fungi-static properties, this compound is used in the packaging of meat, fish, and vegetable products as well.

✧ Zinc oxide has found several uses in the cosmetic industry. It can absorb the ultraviolet radiation of the sun, and thereby protect the skin from sunburn and other damaging effects of UV radiation. It has been approved by the FDA to be used in sunscreen lotions and creams.

✧ It is one of the most important ingredients of mineral makeup. As zinc oxide is not absorbed by the skin, it does not cause any kind of skin irritation. It is also non-comedogenic and nonallergic.

✧ It is also used in deodorants and soaps. It helps remove body odor and prevents the growth of bacteria. It can soothe the skin and protect it from irritants as well.

However, you should be a bit careful while using zinc oxide or its preparations topically. It should not be used for severe burns and wounds. One should also take care that it does not get into the mouth and eyes.

Exposure to zinc oxide fumes can irritate the lungs and cause 'metal fume fever', that can produce flu-like symptoms. So, inhalation of zinc oxide fume is hazardous, though zinc oxide itself is not toxic.