Introduction
Used for decades in countless everyday objects, perfluoroalkyl and polyfluoroalkyl substances (PFAS) are a class of chemical compounds known for their water, grease, and oil-resistant properties. While highly useful, they are also extremely persistent and have been linked to a host of health conditions including; cancer, infertility, and immune and endocrine disorders. Oxyle has developed a breakthrough catalytic destruction technology that effectively degrades and mineralizes all PFAS into non-toxic by-products. To validate the effectiveness of our technology, we conducted a series of toxicity screenings, including a CALUX assay, which is critical in evaluating the reduction of toxicity in treated water.
What is a CALUX Assay?
CALUX Assays are bioanalytical methods used to detect the presence of certain chemicals that can interfere with endocrine systems, for example through thyroid hormone disruption. This assay uses cultured cells genetically engineered to produce a detectable signal when exposed to thyroid-affecting substances. The results are quantified by comparing the induced activity to the response from a known concentration of perfluorooctanoic acid (PFOA), which is set as a toxicity baseline of 1. This allows the assay to plot the toxicity of samples as micrograms of a PFOA equivalent.
How does it work?
The pollutant molecules penetrate the genetically engineered cells’ membranes and bind to the ligands of the thyroid hormone receptors. As a result of a two-step gene expression (via transcription and translation), the cells produce Luciferase proteins that generate a light signal. The change in the intensity of the light signal indicates the change in thyroid activity and therefore, toxicity.
Methodology
To evaluate our technology, we prepared synthetic PFAS solutions containing 20 different compounds with the same concentration. This solution underwent treatment using our catalytic destruction. A third-party partner conducted toxicity analysis both before and after treatment to measure the effectiveness of the PFAS degradation and formation of any potential by-products that would be picked up by the CALUX Assay.
The Results
The PFAS CALUX Assay demonstrated that after our catalytic treatment, a significant reduction in toxicity was observed. For instance, after our treatment, the level of toxicity (thyroid response disruption) in the sample with high PFAS concentration was reduced by 96%. Remarkably, the toxicity levels in the Oxyle-treated water were lower than those found in the control water sample (a popular bottled water). In this context, Oxyle’s technology resulted in even lower disruption to thyroid response compared to established drinking water standards.
CALUX Assays are a crucial metric in the validation process of PFAS elimination, as they provide a direct measurement of the impact of thyroid-disrupting chemicals in water – without having to deal with the complexity of measuring over 10,000 PFAS compounds. Although not the sole indicator, they are an integral part of a suite of bioassays that collectively demonstrate our technology’s capability to effectively address PFAS contamination.
Conclusion
The PFAS CALUX Assay effectively addresses the most critical question: Is the water we’re drinking safe from PFAS or not? These tests are used by regulators around the world to understand the risk posed by PFAS in water. It enabled us to reliably and clearly demonstrate the effectiveness of our technology in significantly reducing PFAS toxicity, ensuring safer, cleaner water for all.