He/Ne laser irradiation produces various shape changes and haemolysis in erythrocytes. Under total absorption conditions, after correcting for the reflection from the surface, blood samples were exposed to various intensities of laser light. The upper limit of these intensities, at which the erythrocytes maintain their normal characteristics, has been used to develop safety levels for the various organs of subjects of varying complexions, assuming that even the cells below the skin layer are not damaged by laser exposures. Depending on the complexion these levels show considerable variations for various organs. © 1984 IFMBE.