Graphology - the study of handwritings; autograph - written with one's own hand; seismograph - a machine noting strength and duration of earthquakes. marina - a harbor for pleasure boats; maritime - relating to the sea; submarine - an undersea boat; aquamarine - color of sea water.
Chemicals are classified into various hazard classifications in accordance with their physiochemical properties and health hazards. Each class of chemical has a pictorial symbol called a danger symbol.
Fire extinguishers with a Class A rating are effective against fires involving paper, wood, textiles, and plastics. The primary chemical used to fight these fires is monoammonium phosphate, because of its ability to smother fires in these types of materials.