Safety marks are used to indicate the presence of dangerous goods and to identify their hazard class. The visible safety marks are generally the labels, placards and UN/product identification number.
Labels are used on packages, cylinders, drums and other small containers. Placards are used on large containers (capacity over 450l) and transport units. UN/Product Identification Numbers are four digit numbers that are assigned to a specific product; e.g., gasoline is UN1203. UN/PIN is required if the dangerous good is in trailerload, truckload or bulk quantities. Please refer to Transport Canada's website for more information about labels and placards.