Office of Security, Safety and Risk Management
Physical Data
This section of the MSDS should provide the necessary physical data to identify a substance. The following physical data is listed in many of the MSDSs but varies depending on whether the substance is a gas, liquid, or solid at room temperature.
- boiling point, ( degree C and/or degree F);
- melting point ( degree C and/or degree F);
- vapor pressure, (mmHg @ 20 degree C);
- vapor density, (air = 1);
- viscosity;
- specific gravity, (water =1);
- evaporation rate, (with butyl acetate = 1);
- solubility in water, (usually by percent);
- solubility in other solvents, (listing solvents substance will dissolve in);
- volatiles by volume, (percent that evaporates);
- odor threshold, (ppm);
- flash point, (many MSDSs list this in Fire and Explosion Data section);
- upper and lower explosion limits, (many MSDSs list this in Fire and Explosion Data section);
An important feature of this section is the appearance and odor description. This description should give the reader an idea of what the chemical looks and smells like at room temperature.
By knowing the physical properties of a substance, the person may be aware of how the material will behave at different temperatures or when it is exposed to water. If the chemical has the properties of low boiling point, high vapor pressure and high volitility, then it is likely to evaporate quickly and therefore present a inhalation hazard. If the chemical is also flammable or toxic, great care must be taken handling this material to prevent fire or overexposure by inhalation.
To see examples of section 3 click on:
The MSDS for bromine begins with the description, ("heavy red-brown liquid with pungent odor"), followed by its important physical data. The MSDS for methylene chloride list the physical data first followed by it appearance and odor description. Methylene chloride has a low boiling point of 40 degreee C, whereas bromine boils at a temperature 19 degrees greater. But the vapor density of bromine is 175 while methylene chloride is twice that at 350. Bromine boils at a higher temperture, but give off vapor at a much greater extent than methylene chloride. Therefore, bromine presents a greater inhalation hazard (coupled with the fact that it is extremely toxic) than methylene chloride.