Well, you certainly have demonstrated a total lack of common sense. Im sorry if this offends you, but you are being judged entirely from what you post. Judging from this thread, one could assume that you were mentally challenged!
To answer your question though, your sassafrass oil will remain useable, as is, for a very long time!
May i suggest that you read some hive literature before posting in future. I think this will prevent any future misunderstanding/frustration. Good day.