**Abstract**

Engineered wood products are used as a construction material due to enhance performance, faster and higher construction of buildings, durability, and less impact on the environment. However, its flammability and resistance to mold, insects and water limits its use in construction, and especially in exterior use. Thus, the necessity of developing wood coating formulations that reduce the impact of the environment and increases the durability of engineered wood products. Biopolymers have attracted considerable interest as alternatives in coating applications for engineered wood products due to their availability, environmentally friendly and compatibility with the main wood components. The focus of this book chapter is to give an overview of the treatment methods and bio-based coating of the engineered wood, with special emphasis on lignin-based coating. Lignin/lignin nanoparticles, due to the presence of functional groups, is a promising polymer for coating formulations and applications. Lignin can produce a significant quantity of char when heated at high temperatures. This is important combustion characteristic when lignin is to be used as coating additive for wood. As such, lignin-based fire retardant and antibacterial action of lignin are important properties when lignin-based coating formulations are developed, and they are discussed in this chapter.

**Keywords:** biopolymers, engineered wood products, lignin-based coating, lignin-fire retardant, antibacterial activity of lignin
