Our railway sleepers goes through a process of high pressure treatment with CCA (Chromate Copper Arsenate) at 500 kPa for 1 hour.
CCA is a preservative obtained by mixing copper, chromium and arsenic compounds, elements that occur naturally in the earth’s crust and atmosphere and are used in the form of oxides. Copper is an excellent fungicide in combination with other materials. On the other hand, Chromium plays an important role in fixing these chemical elements to the wood fibers. Arsenic is part of the CCA composition due to its efficiency against xylophages insects.
Together, the chemical elements of the CCA guarantee the durability of the materials treated against fungi and insects.