Carboy help

I have aquired a few US Labs nalagen 6 gallon carboys from my job. The have never been used for anything but transport r/o water. I was thinking of using them to ferment with primary/secondary. They have a screw on top with seal so I was thinking of drilling hole in cap and putting in a airlock. Is there any reason this would not work for a good carboy. I was thinking of drillling one about 2" up and putting in a ball lock valve. Any suggestions or ideas would be great.

If those handles are hollow, you’ll need to pay close attention to cleaning and sanitizing. If you want to install a valve, look at the Better Bottle racking valves which are made of teflon and come with a piece of tubing to hold the racking piece from the inside while you install through the wall from the outside.

Make sure its BPA free. I wouldn’t suggest it for long term storage either as it may allow oxygen to leach into the beer.
+1 to Shade.

Whats the recycle code on the bottom?

On the bottom it has a recycle code 5 meaning Polypropylene. Does this mean its safe for a carboy? According to the website it is FDA approved.