# Quinacridones as a Building Block for Sustainable Gliding Layers on Ice and Snow

## TL;DR

This paper explores the use of quinacridones as a sustainable, durable gliding layer on ice and snow with minimal environmental impact.

## Contribution

The study evaluates the sustainability and safety of quinacridones using QSAR methods and experimental data.

## Key findings

- Quinacridones form stable, low-abrasion gliding layers due to their low solubility.
- Functional groups in quinacridones enable nanoparticle decomposition and enzymatic degradation.
- Field tests confirm excellent performance of DQA as a gliding layer on snow.

## Abstract

Quinacridone (QA) and 2,9-dimethylquinacridone (DQA) are synthetic substances suitable as a hard, abrasion-resistant, self-organizing gliding layer on ice and snow. For sustainable use, a large number of parameters must be considered to demonstrate that these non-biogenic substances and their by-products and degradation products are harmless to humans and the environment in the quantities released. For this task, available experimental data are used and supplemented for all tautomers by numerous relevant physical, chemical, toxicological and ecotoxicological estimated values based on various Quantitative Structure Activity Relationship (QSAR) methods. On the one hand, the low solubility of QA and DQA leads to stable gliding layers and thus, low abrasion and uptake by plants, animals and humans. On the other hand, the four hydrogen bond forming functional groups per molecule allow nanoparticle decomposition and enzymatic degradation in natural environments. All available data justify a sustainable use of QA and DQA as a gliding layer. The assessment of the toxicological properties is complemented by an investigation of the size and morphology of DQA particles, as well as field tests indicating excellent performance as a gliding layer on snow.