This standard specifies safety colours and photometric requirements for illuminated and internally illuminated safety signs used in workplaces and in public areas for the purpose of accident prevention, fire protection, protection from health hazards and emergency evacuation. This standard applies in connection with DIN ISO 3864-1. DIN 4844-1:2005-05 was the modified adoption of ISO 3864-1:2002. Due to the revision of the International Standard ISO 3864-1 and the new International Standard ISO 3864-4 it has become necessary to revise DIN 4844-1.The background is: a) The previous photometric requirements for internally illuminated and illuminated safety signs from ISO 3864-1:2002 have been replaced by an informative allocation of differing distance factors to corresponding required luminance of the contrast colour or by illuminances on safe condition signs. b) The specification of required contrast between safety and contrast colours and the evenness of the colour regions can now be found in ISO 3864-4. c) The specifications of the relevant colour ranges of safety and contrast colours as they are significantly specified by the CIE and also internationally mandatorily used by other regulators have been replaced by the extended colour regions in ISO 3864-4. The following changes have been made with respect to DIN 4844-1:2005-05: a) division of the content into two standards: DIN ISO 3864-1 and DIN 4844-1; b) this standard now only contains the photometric requirements for internally illuminated and illuminated safety signs and colorimetric requirements; c) clarification of the requirement for required luminance of internally illuminated safety signs in clause 5; d) update of the references for measurement of colorimetric specifications; e) the standard has been editorially revised. This standard has been prepared by Joint Working Committee NA 095-01-06 GA "Sicherheitskennzeichnung" ("Safety marking") of the Safety Design Principles Standards Committee (NASG).