In June 2009, the HSE agreed a comprehensive programme with the UK LPG suppliers for buried metal pipe work to be replaced with newer and more robust plastic pipes. Businesses with buried metallic service pipework, which can corrode over time, were required to replace it with more durable materials, such as polyethylene. The oldest buried metallic service pipework in the least well-maintained condition and located in the most corrosive soils was targeted first.