Linking Seveso with the CLP physical hazards categories

Which physical hazard classifications are currently relevant to Seveso?

Several generic categories of dangerous substances in Annex 1 Part 2 of Seveso cover substances with physical properties:

• Oxidising
• Explosive
• Flammable liquids
• Highly flammable liquids
• Extremely flammable gases and liquids
• Substances which react violently with water or when in contact with water emit flammable gases with risk phrases R14, R14/15 and R29

Identifying the classification of a substance or preparation with physical properties under the EC Dangerous Substances and Preparations Directives is the first step in determining if Seveso applies.  Next, the Notes to Annex 1 Part 2 of Seveso must be applied.  These set out additional criteria to clarify which substances are in scope.

What are the new physical hazards categories in the CLP Regulation?

CLP has 16 classes for physical hazards:

• explosives
• flammable gases
• flammable aerosols
• oxidising gases
• gases under pressure
• flammable liquids
• flammable solids
• self-reactive substances and mixtures
• pyrophoric liquids
• pyrophoric solids
• self-heating substances and mixtures
• substances and mixtures which in contact with water emit flammable gases
• oxidising liquids
• oxidising solids
• organic peroxides
• corrosive to metals

Overall, the physical hazard classes in CLP cover a wider range of properties than the corresponding categories of danger in the current DSD/DPD system. This means that more substances and mixtures would potentially be classified under CLP.

What are the main differences between the DSD/DPD classification system and the new CLP classification criteria?

There is direct read across between DSD/DPD and CLP for only a small number of categories (oxidising gases, oxidising liquids and flammable gases).

In all other cases there are differences between the current classification arrangements in DSD/DPD and the new classes in CLP that could affect the scope of Seveso. These broadly fall into three categories:

• physical hazards in CLP that are currently not relevant to Seveso.  These are: gases under pressure, flammable solids, self-heating substances and corrosive to metals
• physical hazards that are relevant to Seveso and are covered by CLP and DSD/DPD but by a different hazard class and/or with different classification criteria.  This creates potential for the scope and regulatory oversight of Seveso to be changed.  These include classes for: explosives, flammable aerosols, flammable liquids, self-reactive substances and mixtures, organic peroxides, pyrophoric liquids, pyrophoric solids and oxidising solids
• physical hazards included in Seveso but not covered by CLP, which creates the potential for a decreases in the scope and regulatory oversight of Seveso.  Only one current category is affected - substances and mixtures which react violently with water or emit toxic gas in contact with water.

What are the implications of the new GHS/CLP classifications?

Details of the alignment possibilities and their potential impact are contained in the 'Physical Hazards' section of the report of the TWG.

• Report of the Technical Working Group Report on the Application of GHS substances classification criteria for the identification of Seveso establishments.