The three components of Coptrol are specifically exempted from the schedules of the *NHMRC Uniform Poisons Standard.*National Health and Medicine Research Council of Australia. Copper is a normal component of the human body. The total copper content of an average adult ranges from 100‑150 mg and a daily intake of about 2 mg is required.
In normal circumstances, use of Coptrol to treat stock water,dams or waterways will not present toxicity problems. On the contrary, copper deficiency in pastures grazed by sheep and cattle in large areas of NSW, Australia, has been a persistent problem for many years. Hungerford (1975) stated that animals grazing from pastures which contain less than 4 ppm of copper will certainly suffer from copper deficiency. He further suggested that the popular copper sulphate worm drench of earlier years may have masked the inherent copper deficiency over wide areas of pasture in NSW.