Dehydroxanthan Gum is derived from Xanthan Gum (polysaccharide, a sugar-based polymer produced by bacteria) and used as a natural thickener.
The Environmental Working Group (EWG's) Skin Deep is the world's largest personal care product safety guide. They rate ingredients according to their hazard score on a 0-10 scale from low to high hazard. For example, they give water a score of 0.
Accordingly they have rated Dehydroxanthan Gum with a score of 1.