The greatest indication of asbestos on a U.S. Navy ship is it's age. Vessels built prior to 1980 commonly contained high amounts of asbestos in insulating and decking materials as well as pipes and cables. The contaminant, typically a fluffy, fibrous gray padding, was used most often in the lower decks of naval vessels.
Until the dangers of asbestos were revealed in the 1970s, the U.S. Navy used it extensively in vessels, especially in engine and boiler room areas. Twenty crew ratings in that particular military branch are considered at-risk for exposure to the material, most commonly in lower-deck occupations. Even common non-duty areas such as sleeping quarters and mess halls typically had asbestos products. The Navy implemented an abatement program that removed a significant quantity of the contaminant, but exposure to asbestos continues to be an issue for sailors, as of 2015.
Asbestos is a naturally occurring mineral known for its fire-, heat- and chemical-resistant qualities. The toxicity of the material stems from disturbing its fibers, which break off and are inhaled. The resultant long-term exposure to the mineral causes asbestosis, a group of respiratory illnesses including fibrosis and a high rate of pleural cancer. Shipworkers from World War II, for example, were seven times as likely to contract these diseases compared to the national average.