The high-temperature periods of summer and autumn represent peak seasons for hazardous materials (hazmat) transport vehicle failures. Improper operation or maintenance oversights can easily trigger severe accidents, such as cargo leakage. This technical specification establishes standardized operational procedures and mitigation requirements to minimize operational risks.

1. Pre-Trip Safety Inspections

• Placarding and Marking Verification: Ensure that all vehicle and trailer reflective markings, UN number placards, and hazard class labels are intact and clearly visible. The bulk container/tank markings must strictly match the specific Proper Shipping Name (PSN) of the cargo loaded.
• Vehicle Operational Readiness: Verify the integrity and functionality of the braking system, lighting/signaling, and tires. Vehicles with any mechanical or electrical deficiencies are strictly prohibited from entering public roadways.
• Containment and Seal Inspection: Regularly monitor the internal pressure and temperature metrics of the tank. Conduct leak detection on flange contact surfaces, ball valves, and couplings using a soap-bubble solution to proactively identify and eliminate micro-leaks.
• Safety Relief and Discharge Controls: Confirm the operational integrity of all safety relief valves and emergency shutoff devices before departure. Ensure that emergency shear valves, internal valves, and loading/unloading ball valves are fully closed and secured.

2. Cargo Loading Controls

• Properties Awareness: Transport personnel must be thoroughly familiar with the safety data sheet (SDS) properties of the specific hazardous cargo, including flash points, toxicity levels, and thermal expansion coefficients. For substances with high thermal expansion coefficients, use sunshades or thermal blankets and continuously monitor tank pressure variables.
• Dedicated Transport Controls: Enforce a strict dedicated-tank policy. Cross-contamination or mixing of incompatible hazardous materials inside the same containment is strictly prohibited to prevent catastrophic chemical reactions.

3. En-Route Transport Management

• Thermal Risk Mitigation: During periods of extreme heat, implement a “day-rest, night-run” scheduling model to avoid peak daytime temperatures. This prevents product thermal expansion from exceeding the Maximum Allowable Working Pressure (MAWP) of the tank.
• Route Planning and Compliance: Establish and approve fixed transit routes prior to departure, intentionally avoiding unverified infrastructure or poor road conditions. Unauthorized route deviations are strictly prohibited.
• Hazard Avoidance: Prioritize routing that bypasses high-density population zones and peak traffic hours. In the event of an en-route emergency, prioritize moving the vehicle to an open area. If immobilization occurs, immediately activate hazard warning lights and deploy emergency warning devices.

4. Driving Safety Operations

• Credential Compliance: Vehicle operators and transport attendants must carry all legally required transport documents at all times, including Dangerous Goods Transport Licenses, Dangerous Goods Manifests (Shipping Papers), and route permits.
• Load Limit Enforcement: Loading must strictly adhere to the vehicle’s certified gross vehicle weight rating (GVWR) and designated cargo capacity. Overloading is strictly prohibited.
• Fatigue Management: Enforce a mandatory rest period every two hours of driving. Driving while fatigued is strictly prohibited to maintain continuous situational awareness.
• Speed and Space Management: Strictly adhere to specialized speed limits for dangerous goods transport. Maintain safe following distances according to road conditions, and proactively decelerate or detour if congestion is detected ahead.

5. Transfer and Transfer-Site Management (Loading/Unloading)

• Authorized Personnel Access: Cargo transfer operations must be performed exclusively by certified hazmat technicians. Unauthorized individuals are strictly barred from entering the exclusion zone of the transfer site.
• Site Zoning Controls: The designated transfer area shall be used strictly for loading and unloading operations. It must not be utilized as a temporary rest area. Performing non-essential vehicle maintenance or unrelated tasks within this zone is strictly prohibited.
• Adverse Weather Restrictions: Prior to performing transfer operations during thunderstorms, verify that all lightning protection, static grounding/bonding connections, and moisture-proofing safety protocols are fully active and validated.

6. Emergency Response Requirements

• Preparedness and Drills: Fleet operators must conduct regular hazmat emergency response drills and continuously update site-specific and cargo-specific Emergency Response Plans (ERPs).
• Equipment Proficiency: Transport personnel must be proficient in operating all onboard fire suppression systems and emergency equipment. In an emergency, containment and mitigation actions must strictly follow standard operating procedures (SOPs) and response plans.
• Immobilization Signage: If a mechanical breakdown compromises road traffic safety, immediately activate the vehicle’s hazard warning flashers. Deploy reflective warning triangles/devices 50 to 100 meters behind the vehicle on standard roads, and at least 150 meters behind the vehicle on expressways/highways. All personnel must immediately evacuate to the safety zone beyond the road shoulder or guardrail before calling emergency services.
• Uncontrolled Leak Response: In the event of a cargo leak that cannot be mitigated by initial onboard measures, immediately move the vehicle to an open area far from population centers and water resources. Instantly report the incident to the fleet dispatcher and local emergency management agencies, specifying the exact UN number/cargo name, chemical state, and estimated leak volume. Simultaneously initiate an exclusion zone to evacuate nearby civilians, strictly prohibiting bystanders or unauthorized personnel from entering the perimeter.