Acidic materials are corrosive to human tissue. Acidity is commonly measured using the pH scale. Acids have a pH lower than 7. It occurs within a relatively short period.
Exposure is measured in seconds, minutes, or hours relative to inhalation or skin absorption.
Bases are also referred to as alkalis or caustic materials and can be corrosive to human tissue. Basicity is commonly measured using the pH scale. Bases have a pH higher than 7. Flammable substances possessing low boiling points are considered fire hazards. A material with a pH less than 5.5 or greater than 9.5 is a corrosive hazardous material.