International Maritime Dangerous Goods (IMDG) Code: Practical Guide

Introduction

The International Maritime Dangerous Goods (IMDG) Code is the global standard for safe maritime transport of dangerous goods. This guide provides practical information for shippers, freight forwarders, and chemical exporters.

IMDG Code Framework

Legal Status and Application

• SOLAS Convention requirement, mandatory since 2004
• Updated every 2 years, current edition: 2024
• Applies to packaged dangerous goods and container shipping

Structure

• Volume 1: General provisions, classification, training
• Volume 2: Dangerous goods list, appendices, indexes
• Supplement: Emergency procedures (EmS), medical first aid (MFAG)

Classification System

Nine Hazard Classes

Class 1-3: Physical Hazards

• Class 1: Explosives (divisions 1.1-1.6)
• Class 2: Gases (flammable, non-flammable, toxic)
• Class 3: Flammable liquids (flash point criteria, packing groups)

Class 4-6: Health and Physical Hazards

• Class 4: Flammable solids, spontaneously combustible, dangerous when wet
• Class 5: Oxidizing substances, organic peroxides
• Class 6: Toxic substances, infectious substances

Class 7-9: Special Hazards

• Class 7: Radioactive material
• Class 8: Corrosives (acids and bases)
• Class 9: Miscellaneous dangerous goods

Classification Process

1. Identify hazards through test data
2. Apply classification criteria
3. Assign class and packing group
4. Check special provisions

Dangerous Goods List (DGL)

DGL Structure and Use

• UN number, proper shipping name, class
• Subsidiary risk, packing group
• Special provisions, packaging requirements
• Emergency procedures codes

Selection Process

1. Identify correct UN number
2. Select proper shipping name
3. Verify class and packing group
4. Check special provisions
5. Determine all applicable requirements

Common Chemical Examples

• UN 1090: Acetone, Class 3, PG II
• UN 1789: Hydrochloric Acid, Class 8, PG II
• UN 1993: Flammable Liquid N.O.S., technical name required

Packaging Requirements

Performance Standards

• Drop test, leakproofness test, stack test
• Internal pressure test for liquids
• UN marking requirements

Packaging Codes

• Drums: 1A1 (steel), 1H1 (plastic)
• Jerricans: 3A1, 3H1
• Boxes: 4G (fiberboard), 4C1 (wood)
• Composite: 6HA1, 6HH1

Intermediate Bulk Containers (IBCs)

• Metal, flexible, rigid plastic, composite types
• Maximum 3 cubic meters, 3000 kg
• Specific testing requirements

Labeling and Marking

Package Marking Requirements

• Proper shipping name and UN number
• Shipper and consignee information
• Gross and net mass
• Durability and legibility standards

Hazard Labels

• Diamond shape, minimum 100mm x 100mm
• Color and symbol specifications
• Class number display
• Placement requirements

Handling Labels

• Orientation arrows
• Cargo aircraft only
• Limited quantity
• Environmentally hazardous
• Marine pollutant

Documentation

Dangerous Goods Declaration

• Shipper and consignee information
• Proper shipping name, UN number, class
• Packing group, quantity, flash point
• Marine pollutant indication
• Emergency contact information
• Signed declaration

Container Packing Certificate

• Container number and shipper name
• Declaration of proper packing
• Segregation compliance
• Securing methods confirmation
• Cleanliness and condition

Special Documents

• Emergency response information
• Exemption certificates (when applicable)
• Competent authority approvals

Stowage and Segregation

Stowage Categories

• Category A: On deck or under deck
• Category B: On deck only
• Category C: With protection from heat
• Category D: Away from heat sources
• Category E: Special requirements

Segregation Requirements

• "Away from" (Segregation 1)
• "Separated from" (Segregation 2)
• "Separated by complete compartment" (Segregation 3)
• "Separated longitudinally" (Segregation 4)

Segregation Groups

• Acids, alkalis, amines
• Cyanides, explosives
• Flammable liquids, oxidizers
• Organic peroxides

Container Packing

Packing Requirements

• Clean, dry, no incompatible residues
• Proper securing and weight distribution
• Compatibility checks
• Ventilation when required

Securing Methods

• Timber blocking and bracing
• Air bags and dunnage
• Strapping and lashing
• Load distribution considerations

Inspection Requirements

• Pre-packing: Container condition, cleanliness
• Post-packing: Proper securing, door closure
• Seal application and documentation

Port Operations

Reporting Requirements

• 24-hour advance notice typical
• Dangerous goods manifest
• Special requirements notification
• Emergency contact information

Handling Procedures

• Proper equipment and trained personnel
• Weather considerations
• Emergency preparedness
• Storage in designated areas

Emergency Response

EmS Guide (Emergency Procedures)

• Fire emergencies by class
• Spill emergencies
• Specific procedures by UN number
• Protective equipment requirements

MFAG (Medical First Aid Guide)

• Exposure symptoms recognition
• First aid measures
• Medical treatment guidance
• Antidote information

Incident Reporting

• Reportable incidents: spills, fires, injuries
• Immediate notification requirements
• Written report and investigation
• Corrective actions

Training Requirements

Training Categories

• General awareness: IMDG overview, hazard recognition
• Function-specific: Job-specific requirements
• Safety training: Emergency response, PPE
• Security awareness: Security risks and procedures

Training Records

• Training content and date
• Trainer information
• Competency assessment
• Validity: Every 2 years recurrent training

Conclusion

IMDG Code compliance is essential for safe and legal maritime transport of chemicals. JBSR ensures full IMDG compliance for all sea shipments, providing safe and efficient chemical delivery worldwide.