More info on Fiesta
The EPA/PMRA screening level risk assessment for risk to aquatic organisms did not pose a level of concern for freshwater fish. Thus, EPA did not require on the Fiesta label a risk to fish in the environmental hazards section.
Fiesta is also nontoxic to people and pets, hence the Caution Signal word which is only there due to possible dermal irritation, which is on the label.
The NTA and sodium nitrate are formed as byproducts of manufacturing FeHEDTA. Once the concentrate is diluted (1:25) to the end-use product, only trace amounts of these impurities remain, and they are the same trace impurities that are found in all chelated-iron fertilizers. (Scotts Weed-b-gon has the same impurities but also at extremely low levels as it is already diluted.)
All components of the formulation, including the inerts, impurities, and byproducts, were reviewed and approved by the EPA. In addition, the trace impurities were further assessed by two independent toxicological consulting companies, who both concluded that the amounts were well below levels of concern and did not warrant any additional warning on the label, even in California (Prop 65). These tests were at the highest label rates and assumed multiple blanket applications.
The Government of Canada has conducted a science-based evaluation of NTA, called a screening assessment. Screening assessments address potential for harm to the general population (not including workplace exposures) and the environment. The Government of Canada has concluded that NTA is not harmful to the health of the general population at current levels of exposure.
Additionally, although NTA has the potential to remain in the environment for a long time, it is not expected to accumulate in organisms; therefore, the Government of Canada has concluded that NTA is not entering the environment in a quantity or under conditions that constitute a danger to the environment.
The nation that destroys its soil destroys itself.
Franklin D. Roosevelt