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.
Caustic Chemicals & Bases. Caustics fall into one of two categories: acids and bases. Acids are chemicals whose first atom is hydrogen, and whose pH value is less than 7. Bases are chemicals whose molecular chain ends with an oxygen-hydrogen pair, and whose pH value is greater than 7.