The risks of working with engineered stone have recently been in the media, and compared with asbestos risks.  Whilst the current PI cover does not include asbestos risks, there is no such exclusion for engineered stone.  But that might change in the future.

Engineered stone is widely used in benchtops, and usually machined off site, but there could also be some machining on site.  The risks, as now known, are that the machining process produces a fine dust that contains high levels of silica crystals, and this can cause the deadly lung disease silicosis.

A competent architect is likely to be held to know of that problem, and thus to have a responsibility and duty of care to ensure safety measures are taken if the product is being used, as defined by accepted practice.  Worksafe outlines such measures, so an architect has an obligation – to the extent within their control – to see that these are carried out.  

Obviously an architectural practice has a responsibility to ensure that its employees are aware of the risks and take the necessary precautions on site.  But in addition the architect is in a position to make clients aware of those risks:  that may be relevant in both selecting the product and during its installation.  Whilst the architect might not be able to control the off-site machining of the product, there would be an obligation to select and specify it in a way which recognises the risks and requires them to be addressed both on and off site.

NZACS suggests that engineered stone benchtops are fully pre-templated in MDF to avoid any site cutting;  that all off-site manufacture has to use wet-cutting;  and that a sticker is put on the product to identify the risks.  It is known that some practices have put the product on their prohibited list.

Further information about fabrication guidelines is available at https://impac.co.nz/rcs-accreditation/home/