After extensive product testing for EPA re-registration , it was found that Durion killed all or most of the entire base of the aquatic food chain and I think EPA considered it too harmful for a healthy pond ecosystem. Ruin the food chain = ruin the fishery AND the other many natural balances within a pond - lake. Here is an older discussion from the Pond Boss Forum about durion (aka Karmex). Note the results in the link below for animal testing using durion.

https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=288581#Post288581

Here is something from the link where they studied the affects of Durion (Karmex) in laboratory studies.
A part of the article says - "" This chemical may also cause changes in blood chemistry, increased mortality, growth retardation, abnormal blood pigment and anemia, as seen in animal tests in the laboratory.
Some other symptoms show decreased body weight of offspring, wavy ribs, extra ribs, delayed bone formation, reproductive and embryotoxic effects. Other side effects include methemoglobinemia.""

Thus IMO if there are pets drinking the pond water with Karmex it could affect their health. This also causes me concern if there are children swimming in the water where their absorbent mucous permeable membranes are exposed to the water with the durion / Karmex dissolved in it. Usually the younger the animal or plant the more influence the chemical has on it. All the above is probably why it is not labeled for fish and recreational pond use!