Its Sodium Chloride, (table Salt) only 1 app a year. Not close to water.
In Canada its not even allowed for usage except on Ragweed at the moment.
Check your local state regulations, 25(b) exemptions are not exemptions in all states.
If you use a product as a pesticide its not exempt and is listed as a possibly dangerous/toxic. Simple stuff the NOFA OMRI people get confused.