OK, let kosher boy here clarify a few things. Kosher is for things supervised by rabbis knowledgeable in the field during preparation to make sure that the many rules dictating what is and isn't kosher is observed (hands washed and stuff, machinery not used for non-kosher food or both meat and dairy products). This chemical being labelled as kosher would clear it for use in places where food is used without unkoshering everything. Perhaps in making certain dietary supplements. Kasher is word in some ways different than kosher. Note stresses and pronunciation: ka-SHARE is Hebrew for kosher. KA-shur is the Yiddish pronunciation for the act of making something kosher and kushur is Yiddish for kosher. So kasher on a label means the exact same thing as kosher, though it would usually be spelled in Hebrew/Yiddish.
It is fine and generally better to buy kosher products as their preparation is supervised by yet another group of people. They are, sometimes, more expensive though.
