Due to its properties, asbestos was also used in fireplaces. After time, it can deteriorate and the dust and ash particles may contain asbestos particles, which would pose a great threat to someone
What is refractory mortar and where should it be used?
Fireplace insulation/backfill
Asbestos in old Gas Fireplace / Heater? : r/asbestoshelp
Where Does Asbestos Hide in Homes? (And What to Do if You Find It)
What Is a Chimney Smoke Test and How Is It Done?
What Happened To Real Fireplaces?, by Ben Kleschinsky
Clearing the Air on Asbestos
Asbestos in fireplace : r/asbestoshelp
Hollie Berries - Salamander Stoves - Small Wood Burning Stoves
Adobelite vs others
Can the outside of fireplace (brick and mortar, please see the picture) contain asbestos? : r/asbestoshelp
Asbestos Gallery - UKATA
Chimney Testing & Relining - Flame Check Limited
How to Identify Asbestos in Stoves and Fireplaces