When it comes DANGER placards you could survey a hundred people and most won’t know ( other than Dangerous goods on the side) what LEGAL requirements governs DANGER placards on units. It has a fine line, must meet standard for use.
A dangerous goods safety mark can be a label, placard, orange panel, sign, mark, letter, word, number or abbreviation, or any combination of these things. Dangerous goods safety marks are displayed on a means of containment to identify dangerous goods and to show the nature of the danger they pose. Dangerous goods safety marks give a quick identification of dangerous goods in the event of an emergency situation such as a release of dangerous goods from a means of containment. Dangerous goods safety marks are also an information tool for people involved in transportation, including truck drivers, train crews, loading dock workers, reception personnel at a lab or a hospital and aircraft loading personnel.
And YES, Generally, labels are displayed on small means of containment (capacity less than or equal to 450 L) and placards are displayed on large means of containment (capacity greater than 450 L). For example, labels would be displayed on a box, while a placard would be displayed on a truck carrying the box.
The DANGER placard is optional. It may be displayed on a large means of containment instead of any other placard required by Section 4.15 of the Federal Legislation of the TDG Regulations if two conditions are met:
1. The large means of containment contains two or more dangerous goods that require different placards; and
2. The dangerous goods loaded into the large means of containment are contained in two or more small means of containment. However, there are exceptions to this rule. The DANGER placard cannot be displayed on a large means of containment if: · The dangerous goods have a gross mass greater than 1,000 kg, are included in the same class and are offered for transport by one consignor; · The dangerous goods require an emergency response assistance plan (ERAP); · The dangerous goods are included in one of the following classes: o Class 1, Explosives; o Class 2.3, Toxic Gases; o Class 4.3, Water-reactive Substances; o Class 5.2, Organic Peroxides, Type B; o Class 6.1, Toxic Substances (subject to Special Provision 23); and o Class 7, Radioactive Materials, Category III – Yellow label. If a road or railway vehicle to be transported by ship contains a flammable gas, the flammable gas placard (Class 2.1) must be displayed on the road or railway vehicle.
And in the USA, DANGEROUS placard. A freight container, unit load device, transport vehicle, or rail car which contains non-bulk packages with two or more categories of hazardous materials that require different placards specified in table 2 of paragraph (e) of this section may be placarded with a DANGEROUS placard instead of the separate placarding specified for each of the materials in table 2 of paragraph (e) of this section. However, when 1,000 kg (2,205 pounds) aggregate gross weight or more of one category of material is loaded therein at one loading facility on a freight container, unit load device, transport vehicle, or rail car, the placard specified in table 2 of paragraph (e) of this section for that category must be applied.