There are a few safety precautions you should take when practicing IPT:
1.) NEVER potty your baby in a porta-potty, as drowning could occur. This danger is one reason why I highly recommend the Potty on the Go (about $20), found in my Amazon store. It's nice to always have a safe potty place available for your baby!
2.) Never leave your baby alone on the toilet, as they could fall off. Of course, as they get older you'll be able to use your judgment as to when they can safely be left alone.
3.) Always support babies on the potty when they're not able to sit up by themselves really well.
4.) Even if a baby can sit up really well, still be available to catch them until you're confident of their abilities.