Zinc oxide
Zinc oxide is a mineral-based skincare ingredient widely known for its UV protection, anti-inflammatory, and skin-soothing properties. As a broad-spectrum physical sunscreen agent, it sits on the skin’s surface and reflects both UVA and UVB rays, making it one of the most effective and safest sunscreen ingredients available. Unlike chemical sunscreens that absorb UV rays and convert them into heat, zinc oxide provides immediate protection without irritating sensitive skin.
One of zinc oxide’s standout benefits is its gentle, non-comedogenic nature, making it suitable for all skin types, including sensitive, acne-prone, and rosacea-prone skin. It has anti-inflammatory properties that help calm redness, irritation, and conditions like eczema, psoriasis, and dermatitis. Because of this, zinc oxide is commonly found in calming creams, baby products, and barrier repair formulations.
In addition to sun protection, zinc oxide is known for its oil-absorbing and antibacterial properties, making it beneficial for acne-prone skin. It helps to reduce excess sebum, minimize breakouts, and promote healing by forming a protective barrier over compromised skin. This is why it is often included in spot treatments, anti-acne formulations, and healing balms.
Unlike many chemical sunscreens that can break down and lose effectiveness over time, zinc oxide is photostable, meaning it remains effective for longer periods under sun exposure. It is commonly found in mineral sunscreens, tinted moisturizers, and daily SPF products, often combined with titanium dioxide for additional UV protection. Many reef-safe and eco-friendly sunscreens use non-nano zinc oxide to provide sun defense without harming marine ecosystems.
Although traditional zinc oxide formulations could leave a white cast, modern skincare technology has led to micronized and non-nano versions, which provide better blendability and a more natural finish. Whether used for sun protection, skin healing, or calming inflammation, zinc oxide remains one of the most trusted and effective ingredients in skincare, offering long-term benefits for healthy, resilient skin.
Zinc oxide is an inorganic compound with the formula ZnO. It is a white powder which is insoluble in water. ZnO is used as an additive in numerous materials and products including cosmetics, food supplements, rubbers, plastics, ceramics, glass, cement, lubricants, paints, sunscreens, ointments, adhesives, sealants, pigments, foods, batteries, ferrites, fire retardants, semi conductors, and first-aid tapes. Although it occurs naturally as the mineral zincite, most zinc oxide is produced synthetically.
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| Names | |
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| Other names
Zinc white, calamine, philosopher's wool, Chinese white, flowers of zinc
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| Identifiers | |
3D model (JSmol)
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| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| DrugBank | |
| ECHA InfoCard | 100.013.839 |
| EC Number |
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| 13738 | |
| KEGG | |
PubChem CID
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| RTECS number |
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| UNII | |
| UN number | 3077 |
CompTox Dashboard (EPA)
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| Properties | |
| ZnO | |
| Molar mass | 81.406 g/mol |
| Appearance | White solid |
| Odor | Odorless |
| Density | 5.6 g/cm3 |
| Melting point | 1,974 °C (3,585 °F; 2,247 K) (decomposes) |
| Boiling point | 2,360 °C (4,280 °F; 2,630 K) (decomposes) |
| 0.0004% (17.8°C) | |
| Band gap | 3.2 eV (direct) |
| Electron mobility | 180 cm2/(V·s) |
| −27.2·10−6 cm3/mol | |
| Thermal conductivity | 0.6 W/(cm·K) |
Refractive index (nD)
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n1=2.013, n2=2.029 |
| Structure | |
| Wurtzite | |
| C6v4-P63mc | |
a = 3.2495 Å, c = 5.2069 Å
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Formula units (Z)
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2 |
| Tetrahedral | |
| Thermochemistry | |
Heat capacity (C)
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40.3 J·K−1mol−1 |
Std molar
entropy (S⦵298) |
43.65±0.40 J·K−1mol−1 |
Std enthalpy of
formation (ΔfH⦵298) |
-350.46±0.27 kJ mol−1 |
Gibbs free energy (ΔfG⦵)
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-320.5 kJ mol−1 |
Enthalpy of fusion (ΔfH⦵fus)
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70 kJ/mol |
| Pharmacology | |
| QA07XA91 (WHO) | |
| Hazards | |
| GHS labelling: | |
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| Warning | |
| H400, H401 | |
| P273, P391, P501 | |
| NFPA 704 (fire diamond) | |
| Flash point | 1,436 °C (2,617 °F; 1,709 K) |
| Lethal dose or concentration (LD, LC): | |
LD50 (median dose)
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240 mg/kg (intraperitoneal, rat) 7950 mg/kg (rat, oral) |
LC50 (median concentration)
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2500 mg/m3 (mouse) |
LCLo (lowest published)
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2500 mg/m3 (guinea pig, 3–4 h) |
| NIOSH (US health exposure limits): | |
PEL (Permissible)
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TWA 5 mg/m3 (fume) TWA 15 mg/m3 (total dust) TWA 5 mg/m3 (resp dust) |
REL (Recommended)
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Dust: TWA 5 mg/m3 C 15 mg/m3 Fume: TWA 5 mg/m3 ST 10 mg/m3 |
IDLH (Immediate danger)
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500 mg/m3 |
| Safety data sheet (SDS) | ICSC 0208 |
| Related compounds | |
Other anions
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Zinc sulfide Zinc selenide Zinc telluride |
Other cations
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Cadmium oxide Mercury(II) oxide |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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