Highlights ► 6CNA is important degradation product of acetamiprid and imidacloprid. ► Photolytic and photocatalytic degradation of 6CNA in water is described. ► No publications are available on investigation of the behaviour of 6CNA. ► Stability of 6CNA in water under various environmental conditions was explored. ► Photocatalysis, product identification and toxicity assessment were performed.