The pipe organ is an important part of Europe's cultural heritage. Unfortunately, this noble instrument is now under threat. The lead and lead-alloys used in the organ's pipes have been severely affected by indoor atmospheric corrosion. In order to combat this situation the COLLAPSE project has developed conservation strategies. These have included changing the environment to prevent corrosion in pipes. Organic acids are emitted from wood used in the construction of the organ's windtrunk and windchest. Traditionally, oak has been used in pipe organs. Unfortunately, oak is noted for emitting large amounts of organic acids, especially acetic acid. The temperature and humidity inside the instrument also affects corrosion by influencing the emission rate and corrosion process itself. Techniques and products have also been developed to clean corroded pipes and to protect those pipes already under threat, from further corrosion. The COLLAPSE project has developed a pneumatic valve that can be installed in the organ. The valve automatically ventilates the instrument before it begins to play, removing air laden with accumulated organic acids. The project carried out field studies on selected corroded and non corroded organs in Belgium, Germany, Italy and the Netherlands. The historical Stellwagen organ in St. Jakobi church, Lubeck was severely corroded. The COLLAPSE consortium fitted four valves to the windchest in order to rectify the situation. Organ builders, restorers and owners have now been made aware of the valve through conferences, seminars, written articles and the project website available at www.goart.gu.se/collapse The knowledge and skills developed through the COLLAPSE project will provide cultural institutions, parishes and SMEs new tools for safeguarding Europe's cultural heritage, by preventing pipe corrosion.