Some of the most common concerns new pond owners express are over the safety of wildlife, pets, and people. When they see the recommendations of using in PPE (person protective equipment) for spraying them into the pond, it instantly makes them think that the products are strong, dangerous chemicals.
In reality, aquatic herbicides are closely regulated by the Environmental Protection Agency and are safe for non-target plants and animals if applied in accordance with the product label. Years of research and millions of dollars go into its certification. The product cannot be labeled for aquatic use if it poses any chances of causing significant damage to human health, the environment, or wildlife.
Although rare, a fish kill may occur after a treatment is performed. This is not typically an indicator of an incorrectly performed treatment and not a toxicity issue. In cases of existing poor water quality, where the dissolved oxygen (DO) in the water is already very low, the DO may drop even lower due to the excess decomposition of plant material and algae. This may cause conditions conducive for fish to suffocate. This reinforces the importance of proper training of the chemicals used. You must consider all factors including temperature, seasonal timing, and treatment method to greatly reduce the risk of DO drop.
Are aquatic herbicides dangerous? The answer is no, if applied properly. There are no long-term threats to people, pets, fish, and wildlife if used correctly. Some products do carry swimming, drinking, and irrigation restrictions, and they should be applied with this in mind. Be sure to choose the product that is right for each situation.