Wood Powder as a New Natural Sunscreen Ingredient

With increasing interest in ultraviolet (UV) protection, many efforts have been made to replace synthetic UV filters in sunscreens with natural materials. Wood is a highly scattering natural material mainly due to its cellular structure and can also absorb light through its components such as lignin. In this work, we first apply wood powder obtained from fine grinding of wood as an UV-shielding additive in sunscreens. The powders originating from softwood, hardwood, and waste wood were characterized using photography, color analysis, size analysis, and FTIR spectroscopy. Effects of its addition to a commercial sunscreen on UV-blocking performance were also examined. The wood powders were light in color unlike technical lignin, and when they were added to the sunscreen, they could enhance the sun protection factor (SPF) value significantly. In particular, the softwood powder increased the SPF value more than threefold at a concentration of 5 wt%.