There are three main types of asbestos found in UK buildings: chrysotile (white), amosite (brown) and crocidolite (blue). All three are dangerous and have been banned, but blue and brown are generally considered more hazardous than white. In a finished material you cannot tell them apart by eye — only a laboratory test confirms which type is present.
White asbestos (chrysotile)
The most common type in UK buildings and the last to be banned, in 1999. It was used in cement products, textured coatings like Artex, floor tiles and gaskets. Its fibres are curly, and while it is the least hazardous of the three, it is still a known cause of asbestos-related disease.
Brown asbestos (amosite)
Common in asbestos insulating board (AIB), ceiling tiles, pipe lagging and thermal insulation. Its straight, needle-like fibres make it more hazardous than white, and materials containing it — especially AIB and lagging — usually require licensed removal.
Blue asbestos (crocidolite)
Considered the most dangerous type, with very fine, sharp fibres that are easily inhaled. It was used in sprayed coatings, some lagging and high-temperature insulation. It was the first type banned in the UK and almost always means licensed removal.
Does the type change what you should do?
It changes the risk level and often whether removal must be licensed, but the safe response is the same: do not disturb it, get it sampled and identified by a UKAS-accredited lab, then make a proportionate plan to manage or remove it.