Substance profile
Zinc oxide
Zinc oxide is white or yellowish-white powder; hexagonal crystals and is odorless.
01 · Identification
What Zinc oxide is
Zinc oxide is white or yellowish-white powder; hexagonal crystals and is odorless. Its molecular formula is OZn and its molecular weight is 81.4 g/mol. It melts at 1974 °C.
Under the GHS it carries the signal word Warning.
Other names for Zinc oxide
- ZnO
- Zinc Oxide, Crude
- Zinc Peroxide
02 · GHS classification
Hazards and label elements
Harmonised classification under CLP Annex VI. This is the legally binding classification in the EU; other jurisdictions may differ.
03 · Physical and chemical properties
Zinc oxide properties
Every value is shown with the conditions it was measured under and the source it came from. Where sources disagree, all values are listed rather than one being picked — the difference is usually a different form of the substance, not an error.
| Property | Value | Conditions | Source |
|---|---|---|---|
| Melting point | 1974 °C (3585.2 °F) | HSDB | |
| 1975 °C (3587 °F) | NIOSH | ||
| Density | 5.6 g/cm³ | HSDB | |
| 5.61 g/cm³ | NIOSH | ||
| Solubility | Insoluble in water | HSDB | |
| Soluble in dilute acid | HSDB | ||
| Slowly decomposed by water | decomposes | HSDB | |
| Vapor pressure | 0 mmHg | approx | HSDB |
| Lower explosive limit (LEL) | Noncombustible Solid | NIOSH |
Values compiled from PubChem Laboratory Chemical Safety Summary. Temperatures converted to Fahrenheit for reference.
04 · Handling and storage
Storing and handling Zinc oxide
Storage conditions
Store in airtight containers.
Source: Hazardous Substances Data Bank (HSDB)
Incompatible materials
Slow addition of zinc white (a voluminous oxide containing much air) to cover the surface of linseed oil varnish caused generation of heat and ignition. Lithopone, a denser (air-free) grade of oxide did not cause heating.
Source: Hazardous Substances Data Bank (HSDB)
Reactivity
ZINC OXIDE is insoluble in water. What little solubility it has yields aqueous solutions that are neutral in pH. Intimate mixtures of zinc oxide and chlorinated rubber with or without hydrocarbons or chlorinated solvent react violently, even explosively upon heating [Chem. Trade J., 1962, 151, 672]. Slow addition of zinc oxide to cover the surface of linseed oil varnish caused generation of heat and ignition, [Chem. Trade J., 1933, 92, 278].
Source: CAMEO Chemicals
Planning storage for a mix of chemicals? Check Zinc oxide in the storage compatibility matrix →
Next