Despite assurances from the manufacturer, Safe Klean did not work as a turpentine substitute in making the standard Ralph Mayer painting medium: Although it dissolved almost all the damar resin, Safe Klean formed an emulsion, not a true solution, with the stand oil -- unless I shook the mixture, to form a cloudy liquid, the mixture would separate into two fractions (remarkably not in the same proportions as the Safe Klean and stand oil -- something in the Safe Klean separated out). I cannot recommend Safe Klean for use as a painting medium.
In addition, as Karin pointed out, because Safe Klean contains linseed oil, it is not to be preferred for cleaning brushes. A dedicated brush cleaner, such as the Silicoil she uses (including the clever bottle with the coil in the bottom they sell, to help recycle the solvent), would be preferable, as would a typical solvent.
For cleaning hands, I use "Goop": It is very inexpensive and available at hardware, home, and auto supply stores -- it is used by painters and auto mechanics, both professional and amateur; and because it contains lanolin etc., it prevents hands from chapping, which is particularly good in cold weather (However, because it contains such waxy ingredients, I would not use it to clean brushes). It can also take some paint stains out of clothing.
What then is a safe and effective substitute for turpentine, for clean-up and painting media?
Well, the choice basically comes down to citrus-based products and odorless mineral spirits (OMS). Once again, that chart from Gamblin is instructive...
http://www.gamblincolors.com/materials/solchart.html
...and in addition, you may find similar information from Winsor & Newton (Read the "refresher notes" on solvents and Sansodor)...
http://www.winsornewton.com/Main/Sit...ivencyclo.html
Note that neither recommends citrus-based products (although it should be noted that neither manufacturer sells such a product).
Gamsol, the OMS from Gamblin, has a permissable exposure level of 300 ppm, tied with Sansodor, from W&N: Both are, thus, the safest odorless mineral spirits on the market, as far as inhalation.
The flashpoint of Gamsol is 145 degrees Fahrenheit, slightly lower (and thus more flammable) than that of Sansodor (with a "closed cup flashpoint" of 70 degrees Centigrade, that is 158 degrees Fahrenheit, according to their representative who returned my phone call).
However, to my hypersensitive nose, Sansodor has a slight odor (not entirely unpleasant); whereas Gamsol is virtually odorless -- it is my personal choice.
In the end, if one is to paint in oils -- and to enjoy all their benefits of handling and aesthetic appeal -- then one must either use the water-miscible oil paints (whose whites are ground in oils inferior to linseed and whose handling I personally find difficult) or accept the fact that using solvents is an occupational hazard.
Citrus-based products tend to attack the liver and kidneys; OMS, the nervous and respiratory systems.
The key, as I believe Karin pointed out, is studio safety, for which I refer all to the good advice from Robert Gamblin...
http://gamblincolors.com/safety.html
Good luck to everyone!