One of the biggest changes adopted in  IMDG Code 39^th amendment is segregation of organic peroxides.

Organic peroxides are classified as Type A to Type G under class 5.2 in IMDG Code. Type A is prohibited for transport and Type G is exempted from class 5.2. All organic peroxides are assigned to UN Numbers 3101 to 3120 basis the physical state, solid or liquid, and the need for temperature control during transport.

Some of these organic peroxides may have explosive (class 1) and or corrosive (class 8) subsidiary hazards.

Subsidiary hazard is allocated depending on the concentration of the organic peroxide.  A higher concentration may attract subsidiary hazard but same organic peroxide in lower concentration may not have the properties of subsidiary hazard.

However different organic peroxides belonging to the same chemical family do not react dangerously when they come in contact with each other.

Only peroxyacetic acid, being an acid, has a different property and require segregation from all other organic peroxides.

Organic peroxides of Type G exempted from the criteria of class 5.2 is flammable and belong to class 4.1, flammable solids. However, since they belong to same family of organic peroxides they do not result in dangerous reaction when they come in contact with other organic peroxides.

Citing bove justifications European Chemical Industry Council (CEFIC) submitted a proposal to IMO’s CCC (Sub-Committee On Carriage Of Cargoes And Containers) to add an exemption to segregation of organic peroxides in chapter 7.2 of IMDG Code.

This proposal was accepted by CCC and adopted into IMDG Code 39^th amendment published in 2018 which will come into force from 1^st January 2020.

Under section 7.2.6 Special segregation provisions and exemptions a new table is listed as below:

7.2.6.3.2 between dangerous goods which belong to a group of substances of different classes but for which scientific evidence exists that they do not react dangerously when in contact with each other. Substances within the same table shown below are compatible with one another.

IMDG Code 39-18

Table 7.2.6.3.4

Additionally, below organic peroxides are added to 2.5.3.2.4, List of currently assigned organic peroxides in packagings

In IBC instructions IBC 520 below organic peroxides are added