Cal. Financial Code § 1639

Any documents, letters, or other articles found in a safe-deposit box opened pursuant to Section 1632, which in the judgment of at least two officers of the bank have no intrinsic or marketable value, need not be offered for sale. Any documents, letters, and articles and any other contents which have been offered for sale and for which no purchaser has been found, shall be retained by the bank for not less than one year from the date when the box was opened. At any time thereafter, unless sooner delivered to or on the order of the person in whose name the box stood on the records of the bank, the documents, letters, and articles and also those contents which have been offered for sale and for which no purchaser has been found, may be destroyed in the presence of an officer of the bank, but if no notice of intended sale of the contents of the box has been given pursuant to Section 1635, the bank shall mail a notice of its intention to destroy the documents, letters, and articles at least 30 days before the destruction of the same to the person in whose name the box stood on the records of the bank.