IEC 60695-10-3:2016 specifies a mould stress relief distortion test. It is applicable to electrotechnical equipment including parts made from polymeric materials. This test method is intended to evaluate the effects caused by relief of the residual process-induced stress, set in a moulded polymeric assembly of an end product. This stress relief occurs when the sample (energized or not), is exposed to conditioning at a defined temperature for a defined period of time. The test specimen is considered to have satisfactorily withstood the test if, after conditioning to room temperature, it meets defined test criteria. This basic safety publication is primarily intended for use by technical committees in the preparation of standards in accordance with the principles laid down in IEC Guide 104 and ISO/IEC Guide 51. It is not intended for use by manufacturers or certification bodies. This second edition of IEC 60695-10-3 cancels and replaces the first edition issued in 2002. It constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: - Updated references; - Updated equipment; - Added terms and definitions; - and added Bibliography. Key words: Fire Hazard, Abnormal Heat, Fire Safety Engineering, Mould Stress Relief Distortion Test.