Asbestos insulating board

Asbestos insulating board, also known as "AIB" or by the trade name "Asbestolux", was an asbestos containing board used in the building trade because of its excellent fire resistance and heat insulating properties. These boards were commonly used in the UK from the 1930s up until production was terminated in 1980. AIB tended to contain 25-40% asbestos, with amosite being the most common form of asbestos used, although a mixture of amosite and chrysotile was also common, and crocidolite was sometimes used in older boards and some marine boards.
AIB is softer, more porous and less dense than asbestos cement. This and the fact it contains between two and three times more asbestos than cement makes it far more friable and thus a greater health risk if the boards are disturbed or in poor condition. The National Cancer Institute has said "Asbestos has been used as insulation against heat and fire in buildings. Loose asbestos fibers breathed into the lungs can cause several serious diseases, including lung cancer and malignant mesothelioma (cancer found in the lining of the lungs, chest, or abdomen)"