The global issue of water scarcity is abundantly clear. The Earth may be 70% water, but just 3.5% of it is freshwater. More urgent, global water consumption is growing at twice the rate of the population. By 2025, about 1.8 billion people are expected to live in areas with absolute water scarcity. To combat the global water crisis, consumers are rethinking their use of water in personal grooming. Consumers want products that require less rinsing without compromising product performance. As a result, sustainability is becoming integral to FMCG companies’ business models. To reduce the water footprint in the personal care industry, a few companies have developed water-smart products with a primary focus on “faster rinsing” claims to conserve water. However, there was no established method to adequately measure the rinsing behavior of the hair care product until this work.
Previously, some companies have studied the rinsability of hair care product by focusing on the hair itself, not the hair care formula as it washes off the hair because the rinsed-off conditioners formed colloidal system while it was rinsed-off from the hair surface, which posted a big challenge on the determination of the concentration. In this study, by combining the Beer-Lambert law, or A = εmCl, with the light scattering theory, the calibration curves of the studied conditioners were successfully established, and the concentrations of the rinsed-off conditioners calculated through the measurement of light transmittance using Turbiscan