I don't see why not. Its not harmful to have on your breast while you nurse. I checked the tube it doesn't say anything about diapers but safe and nontoxic to baby's. Hope this helps. Its way cheeper on line to buy I recommend getting two at a time. Its saved me on shipping!
I am not sure what the letters HPA mean, maybe natural hypoallergenic? The product ad says For more information to call: (1-800-292-3794). I know one thing, this cream was great for my nipples/breast while I was breastfeeding. It worked great.