Zinc oxide is a white, powdery mineral that is used for making plastics and other textiles. It also appears in some cosmetics. This mineral is not soluble in water, but it does dissolve in acidic environments. It is known best in the United States as a primary ingredient in sunscreen lotions. When applied topically, zinc oxide offers several important benefits for the skin.
UV Protection
According to Dr. Marilynn Syrett, zinc oxide is one of the safest ingredients for protecting the skin from the harmful effects of ultraviolet ( UV) rays. UV rays penetrate the skin and damage tissue, speeding up the aging process and drying the skin out. These rays also increase the risk of skin cancer. Sunscreens containing zinc oxide filter out UV rays, keeping them from penetrating the skin and causing cell damage.
Skin Healing
Zinc oxide is also effective for healing the skin. It can be used to heal wounds, reduce the tenderness associated with sunburns and soften chapped skin. Jonathan Moore, DPM, notes that people who are zinc deficient typically experience slower wound-healing times. When zinc oxide is applied to the wound area, it provides the body with the extra zinc it needs to repair skin cells. Zinc oxide helps keep the wound area moist and clean.
Zinc oxide is an inorganic compound with the formula ZnO. ZnO is a white powder that is insoluble in water, and it is widely used as an additive in numerous materials and products including rubbers, plastics, ceramics, glass, cement, lubricants, [ 2] paints, ointments, adhesives, sealants, pigments, foods ( source of Zn nutrient) , batteries, ferrites, fire retardants, and first-aid tapes. It occurs naturally as the mineral zincite, but most zinc oxide is produced synthetically.[ 3]
The applications of zinc oxide powder are numerous, and the principal ones are summarized below. Most applications exploit the reactivity of the oxide as a precursor to other zinc compounds. For material science applications, zinc oxide has high refractive index, high thermal conductivity, binding, antibacterial and UV-protection properties. Consequently, it is added into materials and products including plastics, ceramics, glass, cement, [ 46] rubber, lubricants, [ 2] paints, ointments, adhesive, sealants, concrete manufacturing, pigments, foods, batteries, ferrites, fire retardants, etc.[ 47]
Rubber manufacture[ edit]
Between 50% and 60% of ZnO use is in the rubber industry.[ 48] Zinc oxide along with stearic acid is used in the vulcanization of rubber[ 18] [ 49] [ 50] ZnO additive also protect rubber from fungi ( see medical applications) and UV light.
Ceramic industry[ edit]
Ceramic industry consumes a significant amount of zinc oxide, in particular in ceramic glaze and frit compositions. The relatively high heat capacity, thermal conductivity and high temperature stability of ZnO coupled with a comparatively low coef
cient of expansion are desirable properties in the production of ceramics. ZnO affects the melting point and optical properties of the glazes, enamels, and ceramic formulations. Zinc oxide as a low expansion, secondary  ux improves the elasticity of glazes by reducing the change in viscosity as a function of temperature and helps prevent crazing and shivering. By substituting ZnO for BaO and PbO, the heat capacity is decreased and the thermal conductivity is increased. Zinc in small amounts improves the development of glossy and brilliant surfaces. However in moderate to high amounts, it produces matte and crystalline surfaces. With regard to color, zinc has a complicated in uence.[ 48]
Medicine[ edit]
Zinc oxide as a mixture with about 0.5% iron( III) oxide ( Fe2O3) is called calamine and is used in calamine lotion. Two minerals, zincite and hemimorphite, have been historically called calamine. When mixed with eugenol, a ligand, zinc oxide eugenol is formed, which has applications as a restorative and prosthodontic in dentistry.[ 9] [ 51]
Reflecting the basic properties of ZnO, fine particles of the oxide have deodorizing and antibacterial[ 52] properties and for that reason are added into materials including cotton fabric, rubber, oral care products, [ 53] [ 54] and food packaging.[ 55] [ 56] Enhanced antibacterial action of fine particles compared to bulk material is not exclusive to ZnO and is observed for other materials, such as silver.[ 57] This property is due to the increased surface area of the fine particles.
Zinc oxide is widely used to treat a variety of other skin conditions, in products such as baby powder and barrier creams to treat diaper rashes, calamine cream, anti-dandruffshampoos, and antiseptic ointments.[ 41] [ 58] It is also a component in tape ( called " zinc oxide tape " ) used by athletes as a bandage to prevent soft tissue damage during workouts.[ 59]
Zinc oxide can be used in ointments, creams, and lotions to protect against sunburn and other damage to the skin caused by ultraviolet light ( see sunscreen) . It is the broadest spectrum UVA and UVB reflector that is approved for use as a sunscreen by the FDA, [ 60] and is completely photostable.[ 61] When used as an ingredient in sunscreen, zinc oxide blocks both UVA ( 320– 400 nm) and UVB ( 280– 320 nm) rays of ultraviolet light. Zinc oxide and the other most common physical sunscreen, titanium dioxide, are considered to be nonirritating, nonallergenic, and non-comedogenic.[ 62] Zinc oxide is, however, slightly absorbed into the skin [ 63]
Many sunscreens use nanoparticles of zinc oxide ( along with nanoparticles of titanium dioxide) because such small particles do not scatter light and therefore do not appear white. There has been concern that they might be absorbed into the skin, [ 64] [ 65] and a study published in 2010 found that nanoparticles of ZnO that were applied to human skin via sunscreens could be traced in venous blood and urine samples.[ 66] In contrast, a comprehensive review of the medical literature from 2011 says that no evidence of systemic absorption can be found in the literature.[ 67]
Zinc oxide nanoparticles can enhance the antibacterial activity of Ciprofloxacin. It has been shown that nano ZnO which has the average size between 20 nm and 45 nm can enhance the antibacterial activity of Ciprofloxacin against Staphylococcus aureus and Escherichia coli in Vitro. The enhancing effect of this nanomaterial is concentration-dependent against all test strains. This effect may be due to two reasons. First, Zinc Oxide nanoparticles can interfere with NorA protein. NorA is a protein which is developed for conferring resistance in bacteria and has pumping activity that mediate the effluxing of hydrophilic fluroquinolones from a cell. Second, Zinc Oxide nanoparticles can interfere with Omf protein. Omf is a membrane protein that is responsible for the permeation of quinolones into the cell.[ 68]
Cigarette filters[ edit]
Zinc oxide is a constituent of cigarette filters. A filter consisting of charcoal impregnated with zinc oxide and iron oxide removes significant amounts of HCN and H2S from tobacco smoke without affecting its flavor.[ 47]
Food additive[ edit]
Zinc oxide is added to many food products, including breakfast cereals, as a source of zinc, [ 69] a necessary nutrient. ( Zinc sulfate is also used for the same purpose.) Some prepackaged foods also include trace amounts of ZnO even if it is not intended as a nutrient.
Pigment[ edit]
Zinc white is used as a pigment in paints and is more opaque than lithopone, but less opaque than titanium dioxide.[ 3] It is also used in coatings for paper. Chinese white is a special grade of zinc white used in artists' pigments. It is also a main ingredient of mineral makeup.[ 70]
UV absorber[ edit]
Micronized and nano-scale zinc oxide and titanium dioxide provide strong protection against UVA ultraviolet radiation, and are used in suntan lotion, [ 71] and also in UV-blockingsunglasses for use in space and for protection when welding, following research by scientists at JPL.[ 72]
Coatings[ edit]
Paints containing zinc oxide powder have long been utilized as anticorrosive coatings for metals. They are especially effective for galvanized iron. Iron is difficult to protect because its reactivity with organic coatings leads to brittleness and lack of adhesion. Zinc oxide paints retain their flexibility and adherence on such surfaces for many years.[ 47]

Specifications :
• Appearance : White and fine powder
Attributes :
• Excellent performance
• Stability in normal temperature
• Without lumps and free flowing powder
• Odorless chemical
• Soluble in acid
• Alkali and ammonium chloride solution
- ZnO Content = 99.95 %
- PbO = 0.002 %
- Sieve Residu = 0.002 %
- Insoluble HCl = 0.01
- Moisture Content = 0.02 %
- Ignition Loss = 0.16 %