The present invention discloses high purity E-1-chloro-3,3,3-trifluoropropene (1233zd(E)) and methods to produce the same. More specifically, the present invention discloses the methods of making 1233zd(E) essentially free of toxic impurities (e.g. 2-chloro-3,3,3-trifluoropropene (1233xf), chlorotetrafluoro-propene (1224), and 3,3,3-trifluoropropyne). The present invention further provides methods for making high purity 1233zd(E) with concentration of 1233xf and 1224 at or below 200 parts per million (ppm) and 3,3,3-trifluoropropyne impurities at or below 20 ppm. Formation of 1233xf impurity can be avoided if pure 1,1,1,3,3-pentachloropropane is used as a starting material. It was also found that formation of 1233xf is avoided if a liquid phase manufacturing process is used.