[en] The International Atomic Energy Agency (IAEA) has established a programme of work to develop safety standards related to the protection of the environment from the effects of ionizing radiation, in cooperation with other national and international organizations undertaking related work. The focus for the IAEA work has been on the identification of the ethical basis and the corresponding protection principles for environmental protection in general and with application to radiation in particular. This paper will provide a summary of progress. Three representative ethical viewpoints have been considered that reflect the spectrum of views on the environment and man's interaction with it - anthropocentric, ecocentric and biocentric ethics. Five broad principles have been identified that are incorporated in international legal instruments, and thus represent a consensus reached by signatories from many different cultural and ethical backgrounds. These are: sustainability, maintenance of biodiversity, conservation, environmental justice, human dignity. The identified protection principles are discussed in the light of the representative ethical viewpoints. In order to develop a practical framework for assessing the impact of ionizing radiation on the environment, it is necessary to link measurable components of the five principles with scientific information relating to radiation-induced changes. Four types of effect have been considered (morbidity, mortality, reduction in reproductive success and scorable cytogenetic effects), all of which are relevant to each of the above protection principles. In order to assess the impact of radiation on the environment, and to make decisions about its protection, it is necessary to relate these effects to measurable environmental quantities and this is the subject of on-going research by other organizations. The implications of both the identified principles and current scientific knowledge on the effect of radiation on living tissue for the development of radiation protection philosophy is discussed. Factors affecting the choice of measurable endpoints and approaches to develop a framework to aid decision-making environmental radiation protection are explored. (author)