Chromated copper arsenate (CCA) is a wood preservative that has been used for timber treatment since the mid-1930s. It is a mix of chromium, copper and arsenic (as Copper(II) arsenate) formulated as oxides or salts, and is recognizable for the greenish tint it imparts to timber. CCA was invented in 1933 by Dr. Sonti Kamesam, an Indian scientist, and was awarded its first patent (British) in 1934. CCA is known by many trade names and is the world’s most widely used wood preservative. It is manufactured to national and international standards depending on the country of intended use, including AWPA P23-10 for the USA and SANS 673 for South Africa, and each manufacturer needs to comply with these standards.