Zinc is more available in younger plant tissues and seeds. Assuming a 50 ppm in the produce 500g of peas, beans, peanuts and cereals should supply a daily amount of zinc of Zinc Toxicity Zinc is not known to be toxic until it reaches levels approaching 500 mg. It can be leached from galvanized containers and pipes, especially in an acid environment, so galvanized products should not be used in a hydroponic system. Zinc sulfatecan be ingested by accident, and induces heavy vomiting. Death usually occurs in 24 hours of taking large doses.
Zinc sulfate looks like and can be confused with Epsom salts.
It usually takes about 2 ounces to induce death. It is very causic and can damage tissues.