When must placards be posted on a loading vehicle with explosives?

Placards must be posted on a loading vehicle with explosives as soon as the first asset is loaded to ensure immediate identification of the hazardous material being transported. This requirement is crucial for safety and compliance reasons, as it alerts personnel and emergency responders about the presence of explosives. Early signage allows everyone in the vicinity to recognize potential hazards, facilitating appropriate safety measures and precautions during operations. By placing the placards right after the first asset is loaded, you ensure that the vehicle is compliant from the start of its loading process, thus minimizing risks throughout the loading and transport phases.