Testing for asbestos in sand
A technical advisory note for businesses and industry on testing for asbestos in consumer products containing sand such as toys, hobby and decorative products.
Technical advisory note
Asbestos is a naturally occurring group of fibrous minerals that occurs in different mineral forms and fibre types. These fibres can vary significantly in their physical characteristics, including length, thickness, and shape. Some asbestos fibres are relatively coarse and more easily detected, while others are extremely thin making them more difficult to identify. All asbestos fibre types, regardless of size, have the potential to pose a health risk if fibres become airborne and are inhaled.
UK regulations prohibit the placing on the market of products containing asbestos fibres due to their classification as carcinogens. This document sets out OPSS’ position on the most appropriate testing methodologies for detecting asbestos in consumer products containing sand such as toys, hobby and decorative products.
Polarized Light Microscopy (PLM)
Polarized Light Microscopy (PLM) is an optical microscopy technique that uses polarised light to identify and characterise materials based on their optical properties. PLM can be suitable for materials with relatively high asbestos levels and larger fibres, such as bulk construction materials. However, it is generally not reliable when asbestos is present at low levels, less than ~0.1%, and may miss very fine or thin fibres.
SEM (Scanning Electron Microscopy) and TEM (Transmission Electron Microscopy)
Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) are electron-based laboratory techniques used to detect very small fibres that cannot be reliably identified using standard based optical methods. By using electrons rather than light, these techniques provide a much higher sensitivity and are able to detect asbestos at levels below 0.1% and very fine or thin asbestos fibres.
Recommendation
SEM and TEM are therefore the recommended techniques for detecting asbestos in consumer products containing sand such as toys, hobby and decorative products because they can more reliably identify low asbestos concentrations, below 0.1%, and fine or thin asbestos fibres likely to be present in contaminated products.