I want to remove all BLOBs from a table - set to NULL or EMPTY_BLOB?

Question

I want to remove all BLOBs from an Oracle table that are older than a certain date. I was thinking of running a query like this:

update blob_table set blob_column = NULL where date_column < some_date;

Is it OK to use NULL, or should I really be setting them to EMPTY_BLOB, e.g.:

update blob_table set blob_column = EMPTY_BLOB() where date_column < some_date;