What is Crocidolite Asbestos?

Crocidolite asbestos is more commonly known as blue asbestos due to its coloration and is considered to be one of the most hazardous types of asbestos. It is part of the amphibole family of minerals and is completely banned in the UK as of 1999. Below, we explain important Crocidolite asbestos info including its appearance, health hazards, and uses. 

An Introduction to Crocidolite Asbestos 

Crocidolite asbestos is easier to identify due to its vivid blue hue although it can be found in different shades of blue-gray too. It has incredibly sharp, needle-like fibres that have a high strength which makes it highly resistant to acids.

The crocidolite fibres are incredibly flexible too and they can typically be bent to 90 degrees without snapping. The fine texture of the fibres means they are ridiculously easy to inhale though, which is why this mineral variety is so hazardous.

Compared to other asbestos types, it was not as widely used commercially, but on a global scale, it still saw much use and distribution.

Quick Crocidolite Asbestos Facts

  • Crocidolite asbestos is part of the amphibole family of inosilicate minerals.
  • It is considered one of the most dangerous types of asbestos.
  • It is believed Crocidolite asbestos is responsible for the most cancer-related deaths.
  • One of its most common uses was for steam engine insulation.
  • Compared to other types of asbestos, Crocidolite has less heat resistance.
  • Crocidolite asbestos along with all other asbestos types is banned in the UK since 1999[1].
  • The scientific name for Crocidolite asbestos is Riebeckite.
  • Crocidolite asbestos was alarmingly found in Kent cigarettes in the US in the 1950s.

Where is Crocidolite Asbestos Commonly Found?

As mentioned, Crocidolite asbestos has a lower heat threshold compared to other asbestos types like Chrysotile. This meant that it was not as widely used and it was generally not included in materials or products that needed heavy insulation. It was commonly found in the following products and areas:

  • Asbestos cement.
  • Asbestos tiles.
  • Asbestos-based insulation.
  • Spray-on asbestos coatings.
  • Pipe insulation.
  • As an additive in some plastics.

It was mainly used as an additive but the spray-on form of crocidolite asbestos was quite popular and this is one of the easiest types to spot on pipes for example due to its blue hue. Crocidolite ceiling tiles were also quite common because the insulation factor required wasn’t as high.

Does Crocidolite Asbestos Cause Health Problems? 

Crocidolite asbestos is actually considered to be one of the most dangerous asbestos types. You can read detailed info on the immune system toxicology here[2], but as a short summary, it can result in the following health conditions: 

  • Pleural disease[3] (lung problems including excess fluid and damage to the lining).
  • Asbestosis (severe lung scarring that can cause breathing problems).
  • Mesothelioma (lung cancer for which there is no definitive cure for at any stage).
  • General respiratory problems such as shortness of breath.

Typically, these health problems can take years to appear as the scarring and lung damage is slow to progress. However, in most instances, the damage is irreversible and has to either be managed with medication, or in severe cases such as Mesothelioma, can be fatal.

It is believe that Crocidolite is responsible for more cancer-related deaths compared to any other asbestos type and is extremely potent when the fibres and dust is breathed in.

This article is part of the "kinds of asbestos" series. Learn more about Chrysotile, Amosite, Tremolite, Anthophyllite


[1] – Legislation.gov The Asbestos (Prohibitions) (Amendment) Regulations 1999

[2] – Science Direct – Crocidolite

[3] – What Are Pleural Disorders from the National Heat, Lung, and Blood Institute

The content on this page/article was last updated on the 21st August 2023 by our team and was reviewed and fact checked by William Wright, DipNEBOSH on the 5th December 2023.

William is a qualified health & safety consultant who holds NEBOSH & IOSH certifications.