Guar Hydroxpropyltrimonium Chloride and Hydroxypropyl Guar Hydroxypropyltrimonium Chloride. Among these guar ingredients, Guar Hydroxypropyltrimonium Chloride is most frequently used in cosmetic products. It may be used in bath products, hair conditioners, hair dyes, other hair care products and skin care products. Guar Gum and the other guar derivatives may also be used in bath products, hair care products, shaving preparations and skin care products.