The general consensus is that they are not. Some reputable sources (Anne Watson, who is a great soapmaker) disagree. But for me, if there is a safety question and I can just zap test, it is *so* much easier, and pretty much fail-proof.
Well, by ruling out the "tongue" (AKA Zap) test, you have told the overwhelming majority of forum members not to reply.
You see, the question is not what the pH is, it is whether there is still free lye in the soap that poses a safety danger to potential users. The test for that is the "zap" test. To test the pH, you need a laboratory, or be willing to spend the money to send your soap into one to get a true pH reading.
As Susie said! (I agree with Susie a lot, I think that we would have great fun eating some of her southern cooking)
To tell the actual pH of a soap you need a good pH meter, properly calibrated, and a 1% soap solution. Then you can get your pH..........
........but what does that tell you? What pH is safe and unsafe? Is that the same from recipe to recipe? No, it isn't. There is no single pH barrier at which soaps are either safe or unsafe. So you would still need to benchmark your soaps somehow in order to know what pH is okay and what is not.
So you benchmark a soap and it has a pH of 11.2. Then you make another batch and it is 11.5. Is that now unsafe?