Vapors

Vapors are the gaseous form of substances that are normally in a liquid state at room temperature and pressure. They are formed by evaporation. Like gases, vapors are measured as a percent volume of air, or ppm.

Vapors may be formed when liquids are heated, such as steam created from boiling water, and some solvents form vapors without being heated.

Most vapors found at maritime worksites come from solvents. A solvent is a substance, most likely a liquid, which dissolves another substance. Common solvents are in paint thinners and adhesives. Many solvents used in the maritime industry cause some form of dermatitis, such as skin dryness, cracking, redness, and blisters. However, when inhaled, solvent vapors can enter the blood stream and travel to other parts of the body, particularly the nervous system, resulting in a toxic exposure.

The temperature at which a liquid gives off vapor is called the flash point. How much vapor is released into the air and how quickly the vapor will fill a space is based on a liquid's vapor pressure. All vapor produced by solvents have densities greater than one. Solvents with a higher vapor pressure produce more vapors, making them more hazardous.

To learn more about Shipyard Chemical Hazards visit our Shipyard Chemical Hazards & Toxic Substances Online Training web page.