Glossary / Physical properties
Melting point
Melting point is the temperature at which a solid changes into a liquid at normal pressure. For most pure substances it is the same as the freezing point, and it helps predict how a material behaves during storage, heating and transport.
Explanation
The melting point tells you what physical state a product will be in at your workplace. A material that melts just above room temperature may arrive as a solid and then liquefy in a warm warehouse, changing how it spills, leaks and pours. Conversely, a liquid with a melting point near room temperature may freeze in cold storage, which can damage containers and valves.
Mixtures and impure materials often melt over a range instead of at a single point, and the SDS may give a range or a freezing point. Some materials decompose or sublime rather than melt, in which case the SDS may state that. Wax-like solids, plastics and many powders can soften before they truly melt.
Heating solids to their melting point introduces other hazards: hot liquid burns, vapors given off by the melt, and sometimes decomposition products. Molten materials are also a particular danger around water, because moisture can flash to steam and throw hot liquid.
Melting point helps in identification and quality checking, and it is part of the physical description used to decide on handling steps and PPE. For dusts, a low melting point can affect how a powder behaves in equipment or when swept up.
What to do and watch for
- Check whether the material may melt or freeze at your storage and process temperatures.
- Keep water away from molten materials unless the procedure allows it.
- Allow for expansion when materials freeze or thaw in closed containers.
Where it appears on an SDS
- Section 9: Physical and chemical properties. Lists the melting point or freezing point, as a single value or a range, or states that it is not applicable.
SDS content and wording vary by supplier. This page is general reference and does not replace the current SDS for your product.