Which of the following is NOT classified as dangerous goods?

Routine maintenance supplies are typically not classified as dangerous goods because they usually consist of items that are safe to handle and transport under normal conditions. These supplies are essential for the regular upkeep of equipment but do not pose significant risks such as toxicity, flammability, or reactivity that categorize materials as dangerous goods. In contrast, fuel and lubricants, explosives, and flammable liquids have specific properties that can be hazardous, making them subject to rigorous regulations to ensure safety during transport and handling. Thus, routine maintenance supplies stand apart from these other dangerous items.