3. ICPE nomenclature headings

Within each part, substances and activities are designated under headings that include a title and a description.

Each heading has a four-digit number. This is the heading number.

• The 1 ^er digit indicates the part of the nomenclature concerned (1 for substances, 2 for activities, 3 for IED activities, 4 for hazardous substances and mixtures).

• The 2nd digit characterizes the substance or activity family: for example, 11XX for the family of toxic substances, in the 1 ^re part of the nomenclature.

• The 3rd and 4th digits characterize the activity or substance.