Wood and wood-based products (Particle board, plywood) can off-gas and cause metals to deteriorate. Shelves in the storerooms are best when made of stainless steel or chlorine and acetate free plastic or powder coated steel. Metals can be damaged by the use of rubber, felt, wool or the oil on our skin, so it is recommended to wear cotton gloves when handling metal objects. Other materials stored with or a part of a metal object, may impact or be impacted by the environment. Organic materials for instance may hold moisture or be more susceptible to deterioration than metals. This could impact the metals' stability. Lighting levels for metal preservation is best kept below 300 lux (up to 150 lux in case of lacquered or painted objects, up to 50 lux in case of objects with light sensitive materials) There are many lighting options available, including LED lights and filters that block harmful ultraviolet rays. Monitoring the condition of the metals assists in determining when and if other conservation measures are needed including restorative conservation work and/or the services of a qualified conservator. Whether written, drawn or photographed, documentation of a metal object will record changes of the object over time. This allows slow deterioration that may go unnoticed to be recognized and alleviated. Interventive conservation Interventive conservation or treatment is an intrusion and a deliberate attempt to alter the physical and/or chemical aspects of an object in an attempt to preserve and/or restore object. "In accordance with NPS Management Policies, conservation treatments are done as a last resort, kept to a minimum, and should be reversible." One of the main proponents of the ethics of conservation is to do nothing. Preserving the original materials and minimizing invasive treatments reduces "the chances of compromising the aesthetic, archaeological, cultural, historical, physical, religious, or scientific integrity of objects." Interventive treatments are needed when an object is disintegrating or fragile and the treatment will protect the object and/or stop the decay. Also the restoration of an object for visual display and presentation is also a possibility which may need pre-thought with discussions and negotiations with the parties involved. Planning will assist in making the best decision in a restorative, interventive treatment for the object and the situation. Similar to many other bronze statues, the statue of Joseph of Portugal had an interventive conservation treatment. The conservation decision made to remove the patina most likely