Synthetic mineral fibres (SMF) is a generic term used to collectively describe a number of amorphous (non-crystalline) fibrous materials including glassfibre, mineral wool and ceramic fibre.

Glassfibre and mineral wool have been used for many decades. The major application of SMF materials is in thermal and acoustic insulation, and as a reinforcing agent.

In some specialized instances, these materials have been used as a replacement for asbestos, especially where high temperature insulation properties are required. Ceramic fibre has also been used to replace refractory brick and mortar materials.

The results of epidemiological and animal studies into the health effects of synthetic mineral fibres have been reviewed and a slightly increased risk of lung cancer in workers employed in the early days of rockwool and slagwool manufacturing has been shown. A suggestive increase has also been indicated in the glasswool sector. This increased risk has not been associated with the duration or intensity of exposure and is not anticipated under currently experienced working conditions.

Although the results in many instances are not conclusive, sufficient evidence exists to state that there is no risk of lung fibrosis or mesothelioma occurring due to synthetic mineral fibre exposure in the manufacturing or user industries.

Skin, eye and upper respiratory tract irritation is possible from non-respirable glassfibre and rockwool fibres.