IATA Class 8 Definitions

Many corrosives are classified as acids. Acidic substances contain hydrogen and dissolve in water to produce one or more hydrogen ions. They react with certain metals and bases or alkalis to form salts. Acidity is measured using a pH scale. Acids have a pH lower than 7. Some examples of acidic substances include hydrochloric acid, sulfuric acid, hydrogen sulfide, and acetic acid.

Two common corrosives are gallium and mercury. Gallium is a silvery-white metal with a melting point of 29.7° C (85.5° F). It can rapidly penetrate the grain boundaries of aluminum alloys and other metals and cause embrittlement. Mercury, also referred to as quicksilver, is a liquid metal at normal temperatures and has a boiling point of 356.73° C (674.11° F). It is highly toxic if inhaled or ingested.

Wet cell batteries consist of a series of metal plates immersed in an electrolyte. The electrolyte is either a dilute of sulfuric acid or potassium hydroxide, both of which are extremely corrosive. These liquids are stored in plastic casings. However, damage to the casing can cause leakage or may produce a fire by short-circuiting the terminals. A car battery is a common example of a lead-acid wet cell battery.

Non-spillable batteries are designed and constructed to prevent the leakage of the electrolytes, regardless of the position of the battery, through use of a jellylike electrolyte or porous absorbent separators.

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