[freebeard]

If you can believe someone that goes by Squidly-Diddly.

its ASBESTOS!
https://www.isomatex.com/medias/our-products/MSDS Filava BSB EN vers 2017.pdf
and if not, same difference. No one ever got sick breathing asbestos for the first few years.

Silicate needles vs continuous fibers.

Originally Posted by Wikipedia

Occurrence of Pulmonary Fibrosis & Other Pulmonary Affections in Asbestos Workers, was presented to Parliament on 24 March 1930.[45] It concluded that the development of asbestosis was irrefutably linked to the prolonged inhalation of asbestos dust, and included the first health study of asbestos workers, which found that 66% of those employed for 20 years or more suffered from asbestosis.