In newer school buildings the trend towards tightly sealed construction
design — to reduce noise for example — plus the use of certain
synthetic building materials, toxic paints and varnishes, and items of furniture and
carpets that off - gas chemicals such as formaldehyde, all contribute to indoor air pollution.
When it comes to
carpets, Braungart prefers the
synthetic ones (without toxins of course) that can be recycled in the technosphere, because «a sheep is not
designed to be a
carpet», especially if it involved red wine stains.