Automatic SDS version history and revision control

Version history is the record of how a sheet has changed over its life: each issued revision, its revision number, the date it was prepared, and the ability to look back at earlier versions. Every SDS carries revision metadata — Section 16 of the standard format exists precisely to state the revision and preparation date.

SDS HQ maintains that history automatically for the sheets you author, so the revision information on the document is real and consistent rather than a field someone remembered to update.

When information about a hazard changes, the standard expects the sheet to be updated, and downstream users need to be able to tell one revision from another. If two versions of a sheet are both floating around with the same date and number, no one can say which is authoritative — and the wrong one may be the one guiding how a chemical is handled.

Reliable revision control resolves that: the current sheet is unambiguously current, its issue date reflects when it actually changed, and the trail of prior revisions is available if a question ever arises about what a sheet said at a given time.

Revision control is automatic and grounded in what actually changed, not in the calendar:

• When you re-publish a sheet whose content has actually changed, the revision number advances on its own — detected by comparing the sheet’s content, not by a manual bump.
• The revision date is frozen to the moment of that publish, so it reflects when the sheet genuinely changed rather than floating to today every time it is opened.
• The library flags a sheet as modified since its last issued revision, so you can see at a glance when a re-issue is due.
• You can set a whole-number revision manually where you need to, and the system never silently lowers it.
• Every sheet also records the classification engine version that produced it, so you always know the basis behind a given revision.

The result is version history you can trust without maintaining it by hand — the current sheet is clearly current, and its lineage is intact.