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Fit for the future

The amendments to the IBC Code are being finalized. The revised chapters will presumably come into effect on 1 July 2020. DNV GL is helping customers assess the impact of new requirements will have on their vessels to ensure timely compliance.

Closing the gap between the categorization of new versus existing IBC Code products is the purpose of the amendments to the code being discussed at IMO. The process involves reassessment of all existing products. The finalized new chapters 17 and 18 are expected to pass at PPR5 in early 2018 whereupon they will be submitted to MEPC and MSC for approval and adoption. Unless the time frame changes, the revised chapters will enter into force on 1 July 2020 and bulk transport of chemicals will be subject to the new carriage requirements from that date. This means that a new Certificate of Fitness including a new product list based on the new requirements has to be issued for each chemical tanker.

The IBC Code

Chapter 17 of the IBC Code lists each product and its carriage requirements, such as ship type, tank type, pollution category, ventilation, tank environmental control, electrical equipment, gauging, vapour detection, fire protection as well as additional specific requirements based on toxicity, heat sensitivity, water reactivity, risk of polymerization and other properties. Chapter 18 of the IBC Code specifies several products which are considered to be less hazardous and are therefore not subject to the IBC Code. Chapter 21, originally introduced in 2004, states the criteria for assigning carriage requirements pursuant to Chapter 17 based on physical properties, behaviour and toxicological data.


The main reason for the current review is the fact that the relevant changes could not be incorporated into the 2004 Amendments to MARPOL Annex II and the IBC Code because of time constraints. The 2004 Amendments introduce the new pollution categories X, Y and Z and moved most of the Chapter 18 products to Chapter 17, requiring products such as vegetable oils to be carried on chemical tankers. At the time, only the ship types, tank types and pollution categories were reviewed based on the pollution aspects addressed by MARPOL Annex II for existing products. The safety criteria defined by the new Chapter 21 of the IBC Code and the corresponding Chapter 17 requirements were not discussed in 2004, which left a discrepancy between existing products assessed prior to the 2004 Amendments and new products assessed thereafter. Since then, stricter carriage requirements have often been applied to new products than to comparable pre-2004 products.

To eliminate this discrepancy and close the gap, a full reassessment of Chapters 17 and 18 of the IBC Code was initiated to review the carriage requirements for each and every product, applying the assessment criteria specified in Chapter 21. At the beginning of this process the existing assessment criteria were questioned, especially those for tank and ship types. In some cases these criteria have resulted in disproportionately strict requirements for certain cargoes. It was decided to revise Chapter 21 and the assessment criteria before proceeding with the product assessments in Chapter 17 and 18.

The most important change to Chapter 21 was the introduction of the SVC/LC50 method, which allows the inhalation toxicity of products with very low vapour pressure or next to no vapour emission to be disregarded when determining the ship and tank types. The same principle may optionally be applied to other carriage requirements where inhalation toxicity is a factor. Other, minor adjustments were made to achieve a more realistic outcome when applying Chapter 21.

Ship and tank type

The most significant implication of the revisions is the required change of ship type or tank type for certain products. In particular, a change to Ship Type 1 and/or Tank Type 1G (independent tanks) could be challenging since the available tonnage is limited. A few products, including acetone cyanohydrin among others, will be upgraded to both Ship Type 1 and Tank Type 1G for which there is hardly any appropriate bulk tonnage in existence. There are also volume restrictions for Ship Type 1 and 2 cargoes (1,250 m3/tank and 3,000 m3/tank respectively). To ensure efficient utilization of tank capacity, it may be advisable to use multiple, smaller tanks for the affected products. Other products will be downgraded to Ship Type 3 so larger quantities can be carried in individual tanks.

Toxic products

Under the IBC Amendments, more than 200 products which are currently deemed to be non-toxic will be reclassified as toxic. This typically implies additional requirements for toxic vapour detection, cargo tank vent position, a higher pressure valve opening set point, cargo and vent piping systems, use of stern line arrangements, and the cargo tank location relative to fuel tanks. Compliance with most of these requirements can be achieved through minor modifications. However, cargo tanks located next to fuel oil tanks will no longer be admissible for these products.

There are already various products requiring toxic vapour detection where no such equipment is available, and the revised Chapter 17 will expand this list considerably. Flag state administrations may exempt some ships from this requirement by imposing other operational requirements on the crew and vessel instead, such as using breathing apparatus and protective gear when entering a tank that previously contained relevant cargo, or spaces directly adjacent to it.


One cargo product of particular interest has been methanol, or methyl alcohol as it is called in the IBC Code. Methanol, often carried in large volumes, is currently assigned to Ship Type 3, which allows unrestricted filling and is not affected by any toxicity-related requirements. Methanol was originally intended to receive stricter treatment under Chapter 21 but is now back to Ship Type 3 following submission of new product data and modifications to Chapter 21. However, toxicity-related requirements have been added. An initiative from the industry to further ease the carriage requirements for methanol in deviation from Chapter 21, backed by expert opinions and proper arguments, is expected.


Chemical tanker operators should be proactive and determine the impact of these amendments on their fleets in due time. Depending on charter parties and cargoes of interest, some modifications may be necessary.

As the revised carriage requirements are more or less clear by now and only minor adjustments are to be expected, DNV GL stands ready to assist customers in predicting the impact on any DNV GL-classed vessel that has received a Certificate of Fitness from DNV GL. This service comprises preparation of a GAP report indicating cargoes that may be lost or gained as well as the affected tanks.

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Kristian Johnsen

Kristian Johnsen

Group Leader MARPOL/ Principal Engineer

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