Operational Guide · Registers & Logbooks

# IBC Code and Operations on Chemical Tankers

The IBC Code governs the construction, equipment and operations of ships carrying dangerous chemicals in bulk, classifying ships into three types according to the risk level of the cargo they may carry.

IBC Code chemical tanker chemical carrier dangerous goods

## Operational Explanation

The IBC Code (International Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in Bulk) sets construction and operational standards for tank ships carrying dangerous chemicals in bulk. Ships are classified into three types (Type 1, 2, 3) according to the environmental and safety hazard level of the products they may carry: Type 1 ships carry the most severe-risk products and require the most stringent preventive measures.

Every chemical tanker operates according to a ship-specific Procedures and Arrangements (P&A) Manual, approved by the Classification Society, which governs loading, discharge, tank cleaning and residue management procedures for each product the ship is approved to carry.

## Regulatory Reference

SOLAS Chapter VII, Part B and MARPOL Annex II make the IBC Code mandatory for ships built after 1 July 1986. Amendments to Chapters 17 and 18 (Res. MSC.460(101) and MEPC.318(74), in force from 1 January 2021) moved several products from Chapter 18 (excluded products) to Chapter 17, assigning them a MARPOL Annex II Z pollution category and therefore requiring the Certificate of Fitness for carriage.

## Scope of Application

Tank ships dedicated to carrying dangerous chemicals in bulk, with the crew responsible for strictly complying with the ship-specific P&A Manual and the product compatibility tables before every loading or cleaning operation.

## Procedure / How to Complete It

1. Check that the product to be loaded is expressly permitted in the ship's Certificate of Fitness according to the type (1, 2 or 3) and the intended stowage tank.
2. Consult the P&A Manual's chemical compatibility tables before any operation, to avoid dangerous reactions with residues from previous cargoes.
3. Apply the tank cleaning procedure specific to the previous product, checked against the next product to be loaded.
4. Check the correct operation of the gas detection systems and ventilation plants before every loading/discharge operation.
5. Record every loading, discharge and cleaning operation in accordance with the P&A Manual and the Cargo Record Book for noxious liquid substances (MARPOL Annex II).

## Practical Example

Example: before loading a Category X product (MARPOL Annex II) into a tank previously used for a different product, the crew checks the P&A Manual's chemical compatibility table, carries out the required pre-wash and verifies the absence of incompatible residues before authorising loading.

## Real Cases

Incidents in the chemical tanker sector frequently result from errors in the tank cleaning sequence between incompatible cargoes, with unexpected chemical reactions generated by residues that were not completely removed: this is why the ship-specific P&A Manual, rather than a generic IBC table, remains the binding operational reference for every single operation.

## Common Mistakes Mistake Library

Mistake | Consequence | How to avoid it
--- | --- | ---
Cargo accepted without an explicit check of the ship-specific Certificate of Fitness | Carriage of a product not permitted for the ship type or the intended tank | Always check the Certificate of Fitness before accepting a new product, not just the general IBC classification
Tank cleaning sequence not checked against the compatibility of the previous and next product | Risk of a dangerous chemical reaction or cargo contamination | Always consult the P&A Manual's compatibility tables before every product change
Cleaning operation documentation incomplete or inconsistent with the Cargo Record Book | PSC deficiency and difficulty tracing events in the event of an incident | Record every cleaning and residue discharge stage in real time, not retrospectively
Tank coating and gasket materials not verified as specifically compatible with the product according to the P&A Manual | Coating degradation, cargo contamination or accelerated tank corrosion | Always check the compatibility of coating and gaskets with the specific product in the P&A Manual before loading
Bonding/earthing not carried out for 'static accumulator' products with high electrical resistivity | Build-up of electrostatic charge with risk of ignition during loading operations | Always apply the bonding/earthing procedures required for static accumulator products, in accordance with the P&A Manual
Cargo sampling sequence not planned, with tank openings that are not strictly necessary | Crew exposure to toxic or flammable vapours during avoidable operations | Plan sampling according to the minimum sequence required by the P&A Manual, limiting tank openings

## PSC Observations

PSCOs on chemical tankers check the consistency between the Certificate of Fitness, the ship-specific P&A Manual and the products actually carried, as well as the correct maintenance of the Cargo Record Book for noxious liquid substances under MARPOL Annex II.

## Operational Tips

- The ship-specific P&A Manual always takes precedence over the generic IBC Code tables: consult it for every operation, even when the product seems familiar.
- Do not underestimate the cleaning sequence between incompatible products: it is the most critical stage in chemical tanker operations.
- Always check that the Certificate of Fitness has been updated after structural changes or changes to product classification.

## Checklist

- Certificate of Fitness checked for the product to be loaded
- P&A Manual compatibility tables consulted before the operation
- Tank cleaning sequence checked and documented
- Gas detection and ventilation systems working and tested
- Cargo Record Book updated in real time for every operation

## FAQ

What distinguishes a Type 1 ship from a Type 3 ship under the IBC Code?
Type 1 ships carry the products with the most severe environmental and safety risk and require the most stringent preventive measures (reinforced double hull, greater distance from the shell plating); Type 3 ships carry lower-risk products.
What are the products moved from Chapter 18 to Chapter 17 of the IBC Code?
Under the amendments in force since 2021, several products previously excluded from the Code (Chapter 18) were reclassified into Chapter 17, now requiring the Certificate of Fitness and the assignment of a MARPOL Annex II pollution category (typically Z).
Is the P&A Manual the same for all ships of the same type?
No: it is specific to each individual ship, approved by the Classification Society based on the actual construction features and the products the unit is actually permitted to carry.
What is a 'static accumulator' product and why does it require specific precautions?
It is a product with high electrical resistivity that promotes the build-up of electrostatic charge during pumping; it requires specific bonding/earthing procedures and loading rate limits to prevent ignition from an electrostatic discharge.
Who approves the P&A Manual and how often must it be updated?
It is approved by the ship's Classification Society and must be updated whenever the approved products, the tank's construction features or the relevant operating procedures change, rather than on a fixed predetermined schedule.
What happens if a previous cargo residue is not compatible with the next product and cannot be completely removed?
The next cargo cannot be accepted into that tank until the incompatible residue has been removed according to the required cleaning procedure and verified as compliant; forcing the loading represents a serious risk of a dangerous chemical reaction.
🎬 Additional photos, videos and interactive diagrams for this topic will be available in a future version of the platform.

## Related Topics

Cargo Record Book (Record Book for Noxious Liquid Substances)Liquefied Gases and Operational Notes on the IGC Code

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