Synthetically produced biocides are effective and widely used in low-pH, rinse-off household and personal care applications to preserve products. Isothiazolinones, such as benzisothiazolinone (BIT) and methylisothiazolinone (MIT), are an important biocide family, commonly used as a preservative in in-can, wash-off household and personal care applications. But growing concerns over the years about their safety, particularly in fabric conditioning and cosmetic applications where allergenic chemicals stay in contact with people’s skin for prolonged periods of time, has led to tighter regulatory restriction on their use. New attitudes towards chemicals has also sparked consumer demand for more sustainable, eco-friendly products. This has placed pressure on formulators to find safer and more sustainable biocide alternatives.