Health & Safety


The safety of specifying and using mineral wool insulation

There are many myths and misunderstandings about the safety of mineral wool, which have all been investigated and dispelled by thorough independent research. 

The most up to date situation is given in our Health and Safety Fact Sheet which can be downloaded on the left.

Regulation (EC) No 1272/2008

Regulation (EC) No 1272/2008, Classification, Labelling and Packaging of Substances and Mixtures provides a means to demonstrate lack of carcinogenic potential. Mineral wool meets or exceeds these requirements so is not classified as a carcinogen in EU. Please click on the Mineral Wool HS Fact Sheet 2011 for further information.

Collateral Warranties

Some collateral warranty documents contain clauses relating to a list of ‘prohibited products’ or ‘deleterious materials’, which the architect is required to agree not to use in the construction.

Insulation wool, or mineral wool (glass wool, stone wool or slag wool), which belong to the generic group of man-made vitreous fibres (MMVF) sometimes appear on these lists, although there is no rational reason for their inclusion. In such cases, architects are, typically, asked to guarantee that:

‘no use will be made of materials generally comprised of mineral fibres which have a diameter of 3 microns or less, and a length of 200 microns or less, or which contain any fibres not sealed or otherwise stabilised to prevent fibre migration’.

The use of lists of deleterious materials has come in for considerable scrutiny over recent years and architects are probably now familiar with the publications ‘Good Practice in the Selection of Construction Materials’ by Ove Arup and Partners (Sponsored by the British Council for Offices and the British Property Federation) and ‘BRE Digest 425 - Lists of Excluded Materials, a change in practice’.

For those who still have concerns about signing collateral warranties, the following information should provide total reassurance about the safety of specifying and using mineral wool insulation.

The published guidance indicates that such lists should not be used and that architects and designers use their expertise to select appropriate materials. Materials subject to BS/EN Specifications or BBA approvals are generally considered suitable for the applications concerned. All UK manufactured mineral wool insulation used for construction complies with relevant BS or BBA requirements.

The requirement regarding the diameter and length of fibres is generally not relevant to mineral wool since the manufactured fibre diameter and fibre length are greater than 3 microns and 200 microns respectively.  Although smaller diameters will be present, and shorter lengths will occur due to breakage, they are not generally comprised of sizes prohibited in the warranty.

All pre-formed mineral wool products sold for construction are also bonded, or sealed, in the manufacturing process to give them shape and form. This stabilises the product to prevent fibre migration.  Measurements taken within insulated buildings have shown that the levels of airborne mineral wool fibres are so low that they are not usually detectable.

Following major epidemiological reviews around the world, mineral wool has been shown to be free of any suspicion of causing any form of malignant or non-malignant respiratory disease in workers or the general public.

The considerable increase in scientific and medical evidence and the fact the mineral wool fibres supplied for building insulation do not fall into the definition used in most lists of deleterious materials, supports the view that mineral wool products should not be excluded by such lists, and that architects may sign the documents and specify mineral wool products without any undue concerns.