Key Updates to IMDG Code 40-20: What Shippers Need to Know Before June 2022

The International Maritime Dangerous Goods (IMDG) Code 40-20 Edition enters mandatory force on June 1, 2022. For supply chain partners shipping hazardous materials from China, these revisions impact classification, documentation, packaging, lithium battery rules, and operational controls. Below is a compliance-focused summary aligned with international logistics best practices.

1. General Provisions & Terminology

Radiation terminology: "Radiation level" is replaced with "dose rate" throughout the Code, aligning with IAEA standards for radioactive material transport. Shipments involving radioactive substances may require updated transport documents.
Heightened security: Additional substances with severe consequences are now subject to enhanced security measures, including certain 1.4/1.6 explosives (e.g., UN0512, UN0513) and Category A medical waste (UN3549).

2. Classification Changes (Part 2)

Class 1 (Explosives): Fire testing now permits ISO methods; some 1.4G fireworks meeting default criteria may classify under UN0431 without full Series 6 testing (subject to Competent Authority approval).
Class 2 (Gases): Scope expanded to include pressurized chemicals (UN3500–3505), governed by Special Provision (SP) 362.
Class 5.2 (Organic Peroxides): UN3116 reassigned to UN3118 for bis(4-tert-butylcyclohexyl) peroxydicarbonate; packaging shifted from OP7 to OP8.
Class 6.2 (Infectious Substances): New UN3549 added for solid Category A medical/clinical/veterinary waste containing infectious substances. Liquid Category A waste remains UN2814; Category B waste continues as UN3291.
Class 7 (Radioactive): Seven new radionuclides recognized; SCO-III (surface contaminated objects) classification formalized.
Class 8 (Corrosives): If in vitro tests cannot distinguish Packing Group (PG) II vs. III, assign PG II by default. Four OECD test guidelines (404, 435, 431, 430) are now accepted.
Class 9: UN3363 scope broadened to cover dangerous goods contained in articles, machinery, or instruments.

3. Dangerous Goods List & Special Provisions (Part 3)

New/Revised Entries

UN Number	Proper Shipping Name	Class/Div	Notes
UN0511/0512/0513	DETONATORS, PROGRAMMABLE ELECTRONIC	1.1B/1.4B/1.4S	New entries; Excepted Quantity (EQ) only
UN2522	2-Dimethylaminoethyl methacrylate, stabilized	6.1	PG II; ≤100 mL per inner package
UN3363	Dangerous Goods in Articles/Machinery/Instruments	9	Enhanced applicability per SP301
UN3549	Medical Waste, Category A (human/animal)	6.2	New entry; Packaging P622/LP622 applies

Critical Special Provisions

Lithium Batteries (Key Updates):

SP188: Revised gross mass limits for packages.
SP376: Damaged/defective cells failing UN Manual of Tests criteria must undergo leakage, short-circuit, and physical integrity assessment.
New SP390: Packages containing both batteries installed in equipment and those packed with equipment must bear dual markings (e.g., "UN3091 Lithium metal batteries packed with equipment" AND "UN3481 Lithium ion batteries packed with equipment") and reflect both on transport documents. Button cells inside circuit boards are exempt.

Approval Requirements: SP76 (total prohibition absent national authority approval) removed for seven UN numbers (e.g., UN3126 self-heating corrosive solids). Eight UN numbers (e.g., UN2249 symmetrical dichlorodimethyl ether) moved from SP76 to SP976, requiring approval from origin, destination, and flag state authorities.
Air-Sea Restrictions: New SP123 clarifies five 4.2-division commodities (including UN1372 wet animal fibers, UN1387 wet waste wool) are regulated for both air and sea; prior sea-only restriction deleted.

4. Packaging & Tank Provisions (Part 4)

Explosives: Large Packaging LP101 authorized for 32 explosives (e.g., UN0005).
Medical Waste Packaging: New P622/LP622 details rigid/flexible packaging for UN3549: puncture-resistant inners, ≤30 kg max net per flexible inner, liquid absorption, and secure cushioning.
Gas Packaging (P200): LC₅₀ values revised per ISO 10298:2018 for gases like silicon tetrafluoride (UN1859).
Lithium Battery Packaging (P903): Activated devices (RFID tags, loggers) must comply with electromagnetic radiation limits to avoid aircraft interference.
Organic Peroxides (IBC520): UN3119 (tert-amyl peroxyneodecanoate) approved for IBC transport under specified temperature controls (+0 °C control / +10 °C emergency).

5. Documentation, Marking & Labeling (Part 5)

Labels/Marks: Lithium battery mark minimum size reduced to 100 × 100 mm (may scale to 100 × 70 mm for small packages); non-compliant packages under SP188 must not display it. Non-relevant marks must be removed/covered; flame icon color specifications clarified for Division 2.1.
Documents: Declarations for liquids with Class 3 subsidiary risk must state flash point. Added documentation requirements for refrigerated liquefied gas portable tanks.

6. Packaging Construction & Testing (Part 6)

Aluminum drums require interior linings when used with incompatible materials.
ISO standards updated for pressure receptacle manufacture.
Radioactive material container approvals extended to SCO-III.
Wall thickness requirements revised for metal Intermediate Bulk Containers (IBCs).

7. Operational Controls (Part 7)

Stowage/Segregation: New stowage code H5 assigned to UN2814, UN2900, and UN3549. Stricter segregation between nitrates/chlorates/perchlorates and infectious substances.
Portable Tanks/MEGCs: Onboard filling/discharge prohibited during voyage; actual maintenance end-date recording required.

✅ Action Items for International Shippers

Review SDS and product classifications against updated IMDG 40-20 tables.
Update DG declarations, packing certificates, and lithium battery handling procedures per SP188/376/390.
Ensure packaging suppliers align with P622/LP622, IBC520, and revised IBC/metal drum specs.
Confirm transport documents include flash points where applicable and remove obsolete marks before shipment.