Risks to cultural heritage vary from catastrophic events (such as earthquakes, floods, etc) to gradual processes (such as chemical, physical, or biological degradation). The result is loss of value to the heritage. Sometimes, the risk does not involve any type of material damage to the heritage asset, but rather the loss of information about it, or the inability to access heritage items. So, heritage managers need to understand these risks well so as to make good decisions about protection of the heritage (for future generations) while also providing access for the current generation. ICCROM (Intergovernamental Organisation devoted to protect Cultural Heritage) and the Canadian Conservation Institute have published the “The ABC Method: a risk management approach to the preservation of cultural heritage”.