Normally ligno or sodium gluconate based admixture is inclined to decay in the course of time. To prevent the problem, biocides are widely used and formaldehyde is common material. Our products are low-toxic preservative for various industry which is mainly composed of an organic cyclic compound containing nitrogen and sulfur and is free from heavy metals. It has high anti-microbial activity against bacteria, filamentous fungi and yeasts, so it can protect aqueous products in order to prolong their shelf life.