Eco Freak Out

1. "The Organic Foods Production Act of 1990 requires the Secretary of Agriculture to establish a National List of Allowed and Prohibited Substances which identifies synthetic substances that may be used, and the nonsynthetic substances that cannot be used, in organic production and handling operations."

The List:

http://www.ams.usda.gov/nop/NOP/standards/ListReg.html

2. Phosphoric Acid
Rust removal
Phosphoric acid may be used by direct application to rusted iron or steel tools or surfaces to convert iron(III) oxide (rust) to a water soluble phosphate compound. It is usually available as a greenish liquid, suitable for dipping (acid bath), but is more generally used as a component in a gel, commonly called Naval jelly. As a thick gel, it may be applied to sloping, vertical, or even overhead surfaces. Care must be taken to avoid acid burns of the skin and especially the eyes, but the residue is easily diluted with water. When sufficiently diluted it can even be nutritious to plant life, containing the essential nutrients phosphorus and iron. It is sometimes sold under other names, such as "rust remover" or "rust killer".

2a. The phosphoric acid content of Coca-Cola has been determined to be about 106.0 mg/L.