Surface contamination during heat treatment process can greatly affect the quality of the end products.  Although cleaning the post heat treated parts is considered a value added process in heat treatment, pre heat treated parts cleaning is also important and can influence the outcomes of subsequent processes dramatically.  Heat treatment industries are also facing growing challenges for replacing environmentally unfriendly cleaning chemicals and processes due to their concern for the environment as well as government regulations. This paper will discuss and characterize the surface contaminants which affect the various heat treatment processes and will identify the cleaning processes and the chemistries that are currently being necessary.  Alternatives to hazardous cleaning chemicals will also be discussed in this paper.