insulation
Rock wool/Glass wool Insulation
Rock- or otherwise known as mineral wool insulation is made of natural stone or iron-ore waste fibres combined with a binder. Glass wool is made out of fibres of glass combined with a binder. While using fibres of natural materials sounds great, however, please do keep in mind that until 2002 the World Health Organisation had rock-/ mineral wool on its official list of carcinogens.

Glass wool insulation is currently the most commonly used type of insulation. It does tend to be cheaper than other products. Rock wool and glass wool insulation both can only be applied when protective gear is worn. Both are made out of renewable materials and turned into non degradable materials. Glass wool and mineral wool can be potentially recycled and made into new insulation material, cutting down on landfill.
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Rock and glass wool insulation do both lose on efficiency once they absorb moisture. The fact that they do not let moisture travel through can also potentially lead to damages in the structural frame and lead to rot.
Dr. Marjolein Drent, a lung disease expert of Maastricht University in the Netherlands, summarised the situation: “The effects of the fibres of glass wool and stone wool can be compared to those of asbestos. In the past, we did not know asbestos was very dangerous. The results of the effects of fibres in glass wool and mineral wool are only being seen right now, so we must deal with it carefully. The point is that these substances are harmful, but people do not realise it sufficiently, and that is something we have to worry about. It is too easily accepted that 'we have a replacement for asbestos'. But the replacement may not be as good as we thought it was at the beginning, there is insufficient attention given to this fact.” (3).

Sources:
(3) EU political report, 'What is mineral wool and what are the health concerns?', Author: James Wilson, May 2019