Can I freeze self-rising flour?

I buy King Arthur in bulk and put as much as I can into a five gallon Mylar bag, remove as much air as possible with a straw and then toss in a few oxygen absorbers. Then I seal the bag with a run of the mill woman's flat iron. Put the bag in a 5 gallon bucket and put a lid on it. Provided you keep it in a cool dry place, it will last for years.

Thank you everyone! I'm keeping it in the fridge. This may not be recommended either, but after a massive cleanup (and a lot of foodstuffs tossed out--such a waste!), I don't want to repeat the process. Planning to add a small amount of leavening when I bake to compensate. Recent batch of pancakes came out fairly well with this approach.

Not only can you freeze it, you should. You should for EXACTLY the reason you gave. I've frozen mine for years. The effectiveness of the leavening will deteriorate over time, the same as it would if you kept it at room temperature. I have read you should use it within a year, but I've never had it hang around that long so I couldn't say if it does last that long. I can tell you it will last as long as six months, which is the longest I've ever had it. I freeze mine in zip type freezer bags, with as much air pressed out as I can. So freeze yours with an easy mind.

I'm seeing "Not recommended" for freezing self-rising flour and baking powder which is the main leavener. The moisture fluctuations appears to degrade the baking powder. You might want to find an airtight container for the self-rising flour, to keep the critters out.