Advances in Hair Styling 426 resistance and hold, along with acceptable aesthetic properties such as no tack and low flaking.13 Dehydroxanthan gum, which also has fixative and rheological properties, has the advantage of being naturally derived and does not require neutralization.14 These three polymers are prime examples of exploiting all of the polymer’s features to yield multifunctional benefits. Hair sprays: The global landscape for hair spray products spans across a broad range through the diversity of solvent bases, polymers and blends, propellant types, packaging, components, and the use of auxiliary ingredients for added benefits. These products present the challenge of meeting regional expectations and/or regulatory restraints along with delivering performance, aesthetic acceptability, and compatibility within the completed system. Successful product development requires an intimate knowledge and integration of all of these facets. Regulatory changes, particularly in, but not limited to, the United States, have been a driving force in product modification and adaptation with respect to polymer choices, propellant usage, solvents, packaging, and components. The California Air Resource Board (CARB) has been aggressive in reducing the levels of volatile organic compounds (VOC) in hair styling products since 1993 (see Table 3).15 Canadian authorities, the United States Environmental Protection Agency (EPA), and regional US organizations and commissions such as the Ozone Transport Commission (OTC) have followed CARB’s lead to some extent. Clean Air for Europe (CAFE) may have a future impact in the European Union (EU), though no specifics are available. Regardless of the change or limitation, the solution for compliance often requires more than a simple change in solvent level or propellant type to maintain performance, aesthetics, and compatibility.