This concept is based in part on the pioneering work by Garry Thomson CBE, and his book Museum Environment, first published in 1978. Thomson was associated with the National Gallery in London; it was here that he established a set of guidelines or environmental controls for the best conditions in which objects could be stored and displayed within the museum environment. Although his exact guidelines are no longer rigidly followed, they did inspire this field of conservation. Conservation laboratories Conservators routinely use chemical and scientific analysis for the examination and treatment of cultural works. The modern conservation laboratory uses equipment such as microscopes, spectrometers, and various x-ray regime instruments to better understand objects and their components. The data thus collected helps in deciding the conservation treatments to be provided to the object. Ethics The conservator's work is guided by ethical standards. These take the form of applied ethics. Ethical standards have been established across the world, and national and international ethical guidelines have been written. One such example is: American Institute for Conservation Code of Ethics and Guidelines for Practice Conservation OnLine provides resources on ethical issues in conservation, including examples of codes of ethics and guidelines for professional conduct in conservation and allied fields; and charters and treaties pertaining to ethical issues involving the preservation of cultural property. As well as standards of practice conservators deal with wider ethical concerns, such as the debates as to whether all art is worth preserving. Keeping up with the international contemporary scenario, recent concerns with sustainability in conservation have emerged. The common understanding that "the care of an artifact should not come at the undue expense of the environment" is generally well accepted within the community and is already contemplated in guidelines of diverse institutions related to the field. Practice Preventive conservation Many cultural works are sensitive to environmental conditions such as temperature, humidity and exposure to visible light and ultraviolet radiation. These works must be protected in controlled environments where such variables are maintained within a range of damage-limiting levels. For example, watercolour paintings usually require shielding from sunlight to prevent fading of pigments. Collections care is an important element of museum policy. It is an essential responsibility of members of the museum profession to create and maintain a protective environment for the collections in their care, whether in store, on display, or in transit. A museum should carefully monitor the