That's not stable; the Precautionary Principle suggests that we shouldn't use the Precautionary Principle on the Precautionary Principle, because we cannot rule out the possibility that it would do harm.
It is quite stable to say that we should never use the Precautionary Principle because the principle is logically inconsistent, precisely for this reason. This is stable because refusing to use the principle is not logically inconsistent.
Is the harm that the average ethical review board prevents less than the harm that they cause by preventing research from happening? Are principles such as requiring informed consent from all research participants justifiable from an utilitarian perspective?