Final answer:
Guar Hydroxypropyltrimonium Chloride is used in hair care products as a conditioner and to promote a healthy scalp by reducing microbial load.
Step-by-step explanation:
Guar Hydroxypropyltrimonium Chloride is used as a conditioning agent in various hair care products such as shampoos and conditioners. Derived from guar gum, it effectively conditions hair by neutralizing the negative charges on hair strands that cause static and tangles. Moreover, it is preferred because of its natural origin and its ability to reduce microbial load on the skin or tissue when used in tandem with mild cleansing chemicals, thereby promoting a healthy scalp environment.