Once again, as for questions of mineral spirits, I can only refer to the solvent chart from Gamblin...
http://www.gamblincolors.com/materials/solchart.html
...which is the most comprehensive I've found, and to Ralph Mayer's "bible", The Artist's Handbook.
I'm very glad if BioShield is non-toxic (Does the container carry the "AP Nontoxic" or similar certification label, as does SafeKlean?). All I know is what that Gamblin chart said, that solvents based on citrus peel have harmful vapors (When one source says one thing, and another another, who am I to say?).
As far as cleaning brushes, hands, etc. with soap and water after using SafeKlean, I'm willing to do so for a safe solvent that works like turpentine (which, of course, is very toxic and flammable).
SafeKlean, however, is not "of the same ilk" as Turpenoid Natural, which it was specifically designed to out-compete. In particular, according to Turpenoid Natural's own literature, "since the proportion of Turpenoid Natural in paint mixtures should not exceed 25%, do not use Tupenoid Natural to create washes, glazes or to 'wet' canvas before painting." I was assured from the SafeKlean people that it may be substituted 1:1 for turpentine in the Ralph Mayer standard glazing medium.
Every person's physiology is different, as are every artist's sensibilities. It's good there is a variety of solvents to choose from.