The presence of chlorine in alternative fuels (., sewage sludge, municipal solid waste or incineration ash, chlorinated biomass,) has both direct and indirect implications on cement kiln emissions and performance. Methods have been developed to properly manage chlorine and its potential implications – but it is important that these implications be recognized and managed. Trace levels of chlorine in feed materials can lead to the formation of acidic gases such as hydrogen chloride (HCl) and hydrogen fluoride (HF) (WBCSD 2002). Chlorine compounds can also build-up on kiln surfaces and lead to corrosion (McIlveen-Wright 2007). .