Toxic Blog#3 – The difference between transport classification for corrosive substances/mixtures and CLP/GHS

Ahead of the live training webinar ‘Introduction to Transport Classification for Safety Data Sheets’ (24th March 2020), I asked expert trainer Caroline Raine to explain the difference between classification under transport and supply (i.e. CLP) for corrosive substances.

Classification for corrosive substances & mixtures

Under ADR corrosive substances are allocated to Class 8, this aligns to the most hazardous CLP Category for skin corrosion.

This means that a substance or mixture that ADR classifies as Class 8 & poses a risk to human health would, under CLP be assigned to Skin Corrosion Category 1.

Furthermore, CLP splits Skin Corrosion Category 1 into subclasses (A/B/C) to further define the hazard posed by a substance, and these divisions are aligned to the ADR Class 8 Packing Groups.


Packing Group

CLP Category
I 1A

In addition, CLP/GHS  has Skin Irritant Category 2,  and GHS has Skin Irritant Category 3. Neither of these would be classified as corrosive under ADR.

Serious Eye Damage / Eye Irritant

Under ADR there are no classification criteria for a substance that would be hazardous to eyes. However, under CLP there are two classifications Serious Eye Damage Category 1 & Eye Irritation Category 2.

It should be noted that there is no direct conversion available between ADR to CLP for Eye Damage.

That said, CLP’s bridging principles which, in the lack of experimental data, triggers a Skin Corrosion Category 1 to also be classed as a Serious Eye Damage Category 1.

Corrosive to Metals

A substance or mixture classified under ADR as Class 8 PG.III that does not fulfil the requirements to be classified as corrosive to skin or eyes would be classified under CLP as Corrosive to Metals Category 1Corrosion rate on either steel or aluminium surfaces exceeding 6,25 mm per year at a test temperature of 55oC when tested on both materials.

If you would like to learn more about transport classification for safety data sheets, or classification and labelling for health hazards (CLP/GHS) register for the upcoming training courses.

Classification of Mixtures for Health Hazards in accordance with GHS/CLP on Tuesday 10th March 2020.

‘Introduction to Classification for Transport for SDS’ on Tuesday 24th March 2020 (1400- 1530 UK time) 

This entry was posted in TRAINING COURSES 2012. Bookmark the permalink.