The special provision 238(a) in Chapter 3.3 of the United Nations “Recommendations on the Transport of Dangerous Goods Model Regulations” mainly pertains to the transport requirements for dangerous goods such as lead-acid batteries. The following is a detailed interpretation of this provision:

Regulatory Background

Lead-acid batteries, as a common type of rechargeable battery, contain dilute sulfuric acid solution as the electrolyte, which is corrosive to some extent. During transportation, if the battery is damaged or leaks, it may corrode containers, cargo holds, aircraft cabins, etc., posing serious safety hazards. Therefore, the United Nations “Recommendations on the Transport of Dangerous Goods Model Regulations” has proposed specific transport requirements for lead-acid batteries under Special Provision 238(a).

Provisions

Special provision 238(a) mainly sets forth three testing requirements for the transportation of lead-acid batteries, namely vibration testing, pressure differential testing, and 55°C leakage testing (referred to as the “three tests”). The purpose of these three tests is to ensure that lead-acid batteries can maintain their integrity and safety during transportation, preventing hazards caused by damage or leakage.

1. Vibration Testing

• Test Method: The battery is securely clamped to the vibration machine platform, applying simple harmonic vibrations with an amplitude of 0.8 mm (total displacement of 1.6 mm).
• Frequency Range: Varies from 10 to 55 Hz at a rate of 1 Hz/min.
• Test Duration: For each installation position of the battery (vibration direction), the entire range of vibration frequencies is applied back and forth, requiring a time of 95±5 minutes.
• Test Positions: Equal time tests are conducted on three mutually perpendicular positions of the battery (including injection and exhaust holes in inverted positions).

2. Differential Pressure Test

• Testing Conditions: After the vibration test, store the battery at 24°C ± 4°C for 6 hours while applying a differential pressure of at least 88 kPa.
• Testing Locations: Conduct tests for at least 6 hours in three mutually perpendicular positions of the battery (including the injection and exhaust ports in the inverted position).

3. 55℃ Leakage Test

• Testing Conditions: A non-leaking battery pack, at a temperature of 55℃, will not allow electrolyte to flow out from cracked or fissured casings, with no free liquid present.
• Protective Measures: Short-circuit protection was applied to the electrodes during transportation packaging.

Test Results and Classification

Not tested: Lead-acid batteries can be classified as Class 8 hazardous materials, UN number 2794. Passed vibration and pressure differential tests, but not conducted or failed the 55°C leakage test: Lead-acid batteries can be classified as Class 8 hazardous materials, UN number 2800. 

Sequentially passed all three tests and met relevant packaging requirements for transport regulations: Lead-acid batteries may be exempt from regulatory restrictions.

Notes

It is generally believed that three tests can be conducted when the electrolyte in the battery is not flowing internally. If there is free-state electrolyte in a lead-acid battery, the three tests cannot be performed.

If the tested sample fails, after effective rectification, the customer may submit another sample for testing again, but an additional fee for retesting will be charged.

When batteries are shipped in series and parallel configurations, only individual cell samples need to be provided for the three tests; it is not necessary to send the entire battery pack for testing.

In summary, Chapter 3.3 of the United Nations “Recommendations on the Transport of Dangerous Goods Model Regulations” Special Provision 238(a) imposes strict requirements for three tests on lead-acid batteries during transportation to ensure their safety and integrity throughout the shipping process.

Are there similar regulations for lithium batteries ? 

Whether lithium batteries are considered general cargo in maritime transport mainly depends on whether their lithium content or watt-hour ratio meets the specific provisions of the International Maritime Dangerous Goods Code (IMDG Code), particularly Clause 188 (SP188). The following are the conditions under which lithium batteries can be transported as general cargo according to this clause:

1. Lithium metal or lithium alloy batteries

• The lithium content of a single battery must not exceed 1 gram.
• The total lithium content of a battery pack must not exceed 2 grams.

2. Lithium-ion batteries

• The watt-hour rating (Wh) of a single battery must not exceed 20Wh.
• The watt-hour rating of the battery pack must not exceed 100Wh.

Lithium batteries that meet the above conditions can be treated as general cargo during transportation, but must still comply with certain packaging and labeling requirements. For example, lithium-ion batteries must clearly indicate their watt-hour rating on the outside of the container. With the exception of battery packs installed in equipment or packaged together with equipment, the total weight of all other battery packages must not exceed 30 kilograms. Batteries and battery packs must be placed in completely sealed inner packaging and ensure protective measures against short circuits to prevent contact with conductive materials that may cause a short circuit within the same container. The inner packaging must also be placed in sturdy outer packaging that meets IMDG Code requirements.

It is important to note that even if lithium batteries meet the above conditions and are considered general cargo, different shipping companies or ports may still have their own regulations and restrictions in practice. Therefore, when planning the sea transport of lithium batteries, it is advisable to communicate with the shipping company or relevant authorities in advance to confirm specific requirements. In addition, the transportation of lithium batteries is also subject to other international rules and standards, such as the UN Model Regulations for the Transport of Dangerous Goods.

Why can’t lead-acid batteries be transported by international express delivery ?

In recent years, international express logistics have generally refused to accept lead-acid batteries mainly because they contain electrolytes. Since international express shipments pass through multiple points, there are many uncertainties during transportation. If not placed correctly and instead laid on their side or inverted, it could lead to liquid leakage, contaminating and corroding other items.

Of course, lead-acid batteries can be transported as regular cargo through international air freight, sea freight consolidation, and full container logistics models, but it is necessary to ensure they are properly positioned and packaged using pallets or wooden boxes while indicating “lead-acid battery” on the air waybill.