The screen "Replace Substance Data" is accessible through the menu option "Go to - External Databases." This screen allows you to replace substance data for one or more substances of a specific origin (SOFOS, BIG, ChemWatch, etc.) with data from another source. The links to other parts of SOFOS (department, employee, article, etc.) will reflect the data of the new substance.

Source: you can only choose from the databases for which a license has been acquired and for which the maximum number of substances to be purchased has not yet been reached.

• Complete the "Current origin" field.
• Complete the "New origin" field.

After filling up both fields, any substances with an origin equal to "Current origin" are automatically selected.

Once you have entered the "New origin" field, the system determines the maximum amount of substances that can replaced, considering the license and existing substances. This calculated value is then displayed in the "Max number of substances" field, indicating the maximum number of compounds that can be replaced. You can modify this field as needed.

You can optionally specify if a substance was used after a specific date. You can also select one of the substances on the list to convert.

Next, you specify the number of compounds you want to read per batch. This is useful because reading substances based on the 'Used after'  can take a long time in some cases. In these cases, the system checks the substance's most recent mutation dateand the most recent mutation dates of any article and pot (associated to those articles). By limiting the number of substances that may be read, you can shorten the time it takes to begin updating substance data.

By clicking the 'Read substances' button, you can retrieve the specific number of substances based on the criteria provided. The 'Number of filtered substances' field displays the number of substances you have read but have not converted yet. These substances will not be returned when you click the 'Search substances' button the next time. This prevents a substance that you do not intend to convert or cannot convert from being fetched repeatedly when you use the 'Replace substance data' function at different times. Next to the field is the 'Reset filtered substances' button, which allows previously filtered substances to be included again for retrieval via the 'Read substances' feature.

After entering all the required information, you select the substances in the "To be processed" overview that you want to replace (use the square in the header to select all rows ate once). Next, find the corresponding substance in the "New origin" database for these substances. Because this process can take time, it does not occur automatically; you must initiate it manually. You can accomplish this by clicking the "Get substance info" button. This action searches for possible corresponding substances for all of the selected items at once. Alternatively, you can do this for individual substances by selecting the "Connect" button in the overview.

It may happen that a substance originally from source X can be copied or converted into a SOFOS-substance. If you later decide to revert the SOFOS-substance back to its original source X, you will lose any changes that you made to the SOFOS-substance. To avoid this, you must confirm this action by using the 'Force' button.

After you click the 'Get substance info' button, SOFOS searches for the relevant substance in the "New origin" database for each substance you choose. Initially, it will search using the CAS number, and then possibly the name. If this search returns only one result, the found substance will be linked to the substance being processed, and the status of the substance being processed will be changed to 'Can be replaced'.

If no- or more than one substances are found (the status reads 'Still to be connected'), the substance can be manually linked using the "Connect" button. This button also allows already-connected substances to be linked to another chemical.

After clicking the "Connect" button, the "Search for a substance to replace the substance" screen appears, allowing you to search for a substance in the external database by name or CAS-number. You can start your search by clicking the 'Search substance' button. The overview displays the compounds found. You can select a specific substance, and when you close the screen, it will be linked to the substance that will be replaced.

After a substance has been linked, click the "Process selected" button to replace the data of the selected substances with the data of the linked substances.

The substance data will be replaced which means that any connection to articles or pots will stay intact. After replacing the connected items will reflect the data of the new substance.