Reducing our carbon footprint with tile: Part 3 – Building material transparency, steps 1 & 2
by Scott Conwell, FAIA, FCSI, LEED AP, Director of Industry Development International Masonry Institute
The most basic measure in building sustainably is selecting natural and lasting materials like ceramic tile, stone, and masonry. Part 2 introduced readers to the Material Ingredient Guide, a tool published by Tile Council of North America (TCNA) to help unify and standardize the reporting process, ultimately positioning ceramic tile in a favorable light compared to other finish materials. This article is the third in a 6-part series about the many ways ceramic tile contributes to sustainable project goals.
The Material Ingredient Guide acknowledges the importance of maximizing transparency when reporting material ingredients. To that end, if outlines 4 steps to transparency: Inventory, screen & assess, report, and optimize. This article will look at the first two.
Step 1: Inventory
Inventorying ingredients is how manufacturers categorize and quantify the makeup of their products. It is good practice to report all the ingredients in a material, and if compliance with sustainable building rating systems is a goal, the reporting should be to the minimum specificity of 1,000 parts per million (ppm), with additional incentives possible when ingredients are reported to the higher degree of 100 ppm.
For example, let’s consider ceramic tile and its composition of clay, feldspar, and silica. Manufacturers break down those ingredients even further, to the substance level, quantifying the quartz, aluminum oxide, and iron oxide within the clay, each according to the substance’s unique chemical abstract service registry number (CASRN). The end result is a manufacturer's inventory report with all ingredients reported to the required level of precision and ready for step 2, assessing those ingredients.
Step 2: Screen & Assess
Once manufacturers have quantified their material ingredients in an inventory report, they move to step 2 of the transparency process, screening and assessing. In this stage, the ingredients are evaluated by an objective set of criteria to determine their relative level of toxicity. One common screening tool is the GreenScreen® assessment which scores substances based on persistence (the length of time a chemical can exist in the environment before being destroyed by natural processes), bioaccumulation (the process in which a chemical substance is absorbed by an organism), human toxicity, and ecotoxicity.
Under this GreenScreen® benchmarking method, ingredients are given a score 1 through 4. Benchmark 1 indicates substances to avoid due to high toxicity concerns. Benchmark 2 indicates substances that may be okay but it’s advisable to use a safer substitute. Benchmark 3 indicates substances that may be used, but there is still opportunity for improvement. Finally, benchmark 4 indicates preferred substances with low or no toxicity.
With the transparency goal in mind, the Material Ingredient Guide presents chemicals and substances common to tile, setting materials, and grout with their corresponding GreenScreen® benchmark scores, helping to communicate with designers and specifiers who require material ingredient disclosure.
TCAA contractors should have a basic understanding of material ingredient reporting and the importance of transparency so they can communicate the sustainable benefits of tile to their customers, clients, and stakeholders.
