A complete labelling is not always needed.
There are the following facilitations in labelling of chemicals:
Labelling of bottles in a laboratory according to the TRGS 201
If a risk assessment shows that a complete labelling is not necessary the labelling may be facilitated. This is only possible if there are operating instructions and if the staff has been instructed about the possible hazards at the workplace and the safety measures.
With a facilitated labelling the label must at least contain the name of the compound and the hazard pictograms (CLP-regulation) of the main risk(s) by
- health hazardous or
- environmental risks
of the compound.
If the resulting information of a facilitated labelling is too unspecific, it may be necessary to add a hazard code or other short descriptions.
Solution proposals are found in annex 4 of the BGI/GUV-I 850-0. Unfortunately labels described in this text at the moment are only available at the "Jedermann-Verlag" and are quite expensive. But if you print out CLAKS labels you will find there pictograms and warning phrases.
Labelling of unknown reaction products
Compounds - so far not classified or with unknown structures of course cannot be labelled with H- or P-phrases. Nevertheless according to Section 8 of the Hazardous-Substances Ordinance all these compounds must be identifiable. You may perform this by having a coding system and if you could check by the entries in your lab journal how these compounds have been prepared. This is also a good practice for the scientific aspects of your work.
Labelling of small quantities
For several less hazardous compounds a labelling is not necessary if the size of the bottle is not bigger than 125 ml. See details in the TRGS 200 and in the CLP-regulation. (Use the search engine of your pdf-reader to search for the string "125") Unfortunately the rules are very complicated.