Information for specifiers
Fired ceramic tile and the indoor environment
A practical account of VOCs, environmental impact and the evidence available for the Japanese ceramic tiles supplied by Mittsu.
A simple starting point
The nature of fired ceramic
Ceramic tile is made principally from clay and other inorganic mineral materials. These are formed, dried and fired at high temperature. On a standard glazed tile, the glaze is fused to the ceramic body during firing rather than applied as an organic surface coating after manufacture.
That basic material distinction matters. A volatile organic compound is an organic chemical capable of evaporating under normal indoor conditions. A finished, fired mineral surface without an added organic coating, binder or sealer does not present the same emissions question as paint, adhesive, resin, vinyl or another product containing volatile organic ingredients.
VOCs and indoor air
Why ceramic is treated as inherently non-emitting
Both the US Green Building Council and the International WELL Building Institute identify ceramic as an inherently non-emitting material. Their guidance does not require VOC emissions testing for ceramic where the product has no integral organic-based surface coating, binder or sealer.
Separate emissions certification, such as UL GREENGUARD, is one way of providing test-based evidence for products. It is not the only route recognised by building standards. For an uncoated fired ceramic tile, the relevant basis is the nature of the finished material and the inherently non-emitting provision.
Mittsu does not hold product-specific VOC emissions certificates for these tiles. The absence of a certificate should not be mistaken for evidence that the fired ceramic tile is a source of VOC emissions. If a particular tile receives a separate post-fired coating or sealer, that treatment must be assessed in its own right.
The complete installation
Most VOC questions arise around what is added on site
A tiled finish is more than the tile. Adhesives, primers, waterproofing membranes, grout additives, sealers, coatings and cleaning products can contain organic ingredients and may release VOCs.
These products should be selected using their own safety data, technical information and emissions evidence. Project teams seeking a low-emitting interior should assess the whole installation, with particular attention to wet-applied products and any finish added after firing.
Environmental impact
Durable does not mean impact free
Ceramic manufacture has environmental impacts. Clay and mineral raw materials must be extracted and prepared. Drying and firing require energy. Manufacturing can create emissions and waste, while packaging, international transport, installation and eventual removal add further impacts.
A correctly installed ceramic finish can remain in service for many years. Long service life can reduce the need for replacement, although the actual life of an installation depends on design, substrate, workmanship, use and maintenance.
Environmental Product Declarations use life-cycle assessment to report defined environmental indicators. Mittsu does not currently hold product-specific EPDs for these tiles, so we do not publish unverified figures for carbon, energy, water, waste or other life-cycle impacts. We also avoid broad descriptions such as “zero impact”, “carbon neutral” or “eco-friendly” where the evidence does not support them.
How to use this information
A proportionate basis for specification
Where a project accepts recognised inherently non-emitting materials, this statement explains the basis on which fired ceramic tile without an integral organic coating, binder or sealer can be considered. The project assessor should confirm the selected tile and review all installation products independently.
If a project contract specifically requires a named certificate, product-specific EPD or laboratory report, this general material statement does not replace it. It is an open account of the material and the limits of the evidence available.