Which statement about Triclopyr non-target toxicity is true?

• A. Practically non-toxic to fish, invertebrates, birds, and bees.
• B. Highly toxic to mammals.
• C. Highly toxic to aquatic plants.
• D. Highly toxic to all non-target organisms.

Answer: (A)

Triclopyr’s non-target toxicity profile shows relatively low acute toxicity to many non-target wildlife when used as labeled. That’s why the statement that it’s practically non-toxic to fish, invertebrates, birds, and bees is the best fit. In practice, label directions and risk assessments indicate that exposure at recommended use rates poses low risk to these groups, while the chemical works by targeting broadleaf plants, including many aquatic weeds.

Think of it this way: the main hazard of triclopyr is to broadleaf plants, which is why it’s used for aquatic weed control. The idea that it would be highly toxic to aquatic plants or to all non-target organisms isn’t consistent with its purpose and labeling. It’s not considered highly toxic to mammals, and it isn’t accurate to say it’s universally highly toxic to non-target organisms.