For a classification of a compound it has first to be defined which hazard classes and, where applicable, which categories apply. From every category of a hazard class a H-phrase and a pictogram is derived. If all pictograms of all hazards are put together, the result may be confusing.

Example:

If the following pictograms are derived from a classification,

then the "exclamation mark" has no more warning effect besides the skull. According to article 26 of the CLP-regulation the "exclamation mark" therefore may be omitted. Further simplifications according to artikel 26:

Besides...	... may be omitted
	and
	for irritation of skin or eyes
for respiratory sensitation	for skin sensitation or for irritation of skin or eyes

Are there more than one classifications within a hazard class then only the pictogram of the most hazardous classification applies.

Example:

If in the hazard class "acute toxicity" there is a classification "toxic if swallowed" and a second classification "harmful in contact with skin" then only the skull-pictogram is used for the classification as "toxic".