Oxalic acid and glycerin strips are a clever, effective, and biological way of controlling the dangerous Varroa destructor mite that infects bee colonies.
With the proper application it kills Varroa mites at a rate of <93%, this is possible by adding glycerin to the strips making the preparation effective for 30 days. They are made exclusively in Greece.
Ingredients: Pure cellulose strips, High purity Oxalic Acid 99.6%, High purity Glycerin pharmaceutical 98.5%.

Oxalic acid stripes are cellulose strips immersed in a mixture of an appropriate ratio of high purity oxalic acid over 99.6% and vegetable refined glycerin over 98.5% purity, for biological use against varroa mite.
Oxalic acid is an organic acid with the chemical formula C2H2O4. It is a white solid, relatively strong carboxylic acid. It is found in nature in concentrations of sorrel (commonly nettle) and in many other plants
Vegetable Refined Glycerin is a clear, colorless, odorless, viscous, hygroscopic liquid that is widely used as an ingredient in cosmetics and food.
To summarize: All the ingredients used are suitable for the biological control of Varroa by beekeepers.