Population, economic growth and industrialization in the world increase the amount of waste. A waste policy should be developed and the studies of the waste management should be carried out, especially in the environment causing landfill problems. Recycled polyethylene terephthalate (r-PET) is a widely recycled plastic employed for new textile production in the world. It reduces environmental impact and lowers cost of the production [1]. The influence of the anionic detergent Felosan FOX (CHT/Bezema Group) on the whitness degree and the colour properties of r-PET fibres was determined