Chrysotile Asbestos

Chrysotile, also known as white asbestos, is a member of the Serpentine group, so-named because the fibre is curly. Chrysotile fibres are the most flexible of all asbestos fibres. Chrysotile fibres can withstand the fiercest heat but are so soft and flexible that they can be spun and woven as easily as cotton. Resistance to alkaline attack makes chrysotile a useful reinforcing material in asbestos-cement building products. Chrysotile was banned in the UK in 1999.

Chrysotile was traditionally the most widely used of all asbestos types, accounting for approximately 95% of asbestos mined annually. Like the other forms of asbestos, chrysotile can absorb organic materials such as resins and polymers and can be used to strengthen particulates such as cement.

Amosite Asbestos

Amosite, also known as brown asbestos, is a member of the Amphibole group. Its harsh, spiky fibres have good tensile strength and resistance to heat. In buildings, amosite was used for anti-condensation and acoustic purposes. On structural steel, it was used for fire protection.

Between the 1920s and the late 1960s amosite was used in preformed thermal insulation, pipes, slabs and moulded pipe fitting covers. In the UK amosite was also used widely in the manufacture of insulation boards. The import of amosite was banned as of 1 January 1986 by The Asbestos (Prohibitions) Regulations 1985.

Crocidolite Asbestos

Crocidolite, also known as blue asbestos, is a member of the Amphibole group. The needle like fibres are the strongest of all asbestos fibres and have a high resistance to acids.

Crocidolite was used in yarn and rope lagging from the 1880s until the mid 1960s and in preformed thermal insulation from the mid 1920s until 1950. The high bulk volume of crocidolite makes it suitable for use in sprayed insulation; a product which was first manufactured in this country in 1931 at the JWR factory in Armley.

Crocidolite is known to be the most lethal of all the asbestos types. The import of crocidolite peaked in 1950, fell by 25% in 1960 and by 88% in 1970. The "import, supply and use of crude, fibre, flake, powder or waste crocidolite or amosite" wasn't actually banned until the Asbestos (Prohibitions) Regulations of 1985 came into force, although strict guidelines had regulated its use since 1969.