Keeping CLP and SDS information on file
Under CLP and REACH, you are required to keep all of the information relating to a classification, label or SDS for 10 years from the date of last supply of the product.
This means that you need to keep all of the information relating to the classification of the product which has been used in its current classification, not just the classification information itself.
Similarly, you need to keep a copy of every iteration of an SDS, in both English and any foreign languages.
There is no requirement as to the format of the records being kept, and either paper or electronic records, or a mix o the two are likely to be acceptable. For example, you may have your own handwritten notes, printouts from web pages, and also soft-copy information on your server. In an ideal world, you would have everything either physically as hard copy (including printouts of all electronic documents), or as soft copy (including scans of all handwritten documents or other hard copy documents). In the real world, as long as you can lay your hands on all of the information you need, by whatever route, that should be sufficient.
As the timescale for keeping classification, labelling and SDS information is so long, you need to ensure that you have good archiving facilities for hard copy information; and good ways of retaining soft copy information, e.g. if you change servers, or move from using one particular set of software to another, whether for classification and/or SDS purposes, or even your email system or document authoring software.