terms like "enviromentally safe" and "biodegradable" are thrown around a lot.
So is "eco-friendly" and "green".

Here is the truth. As far as I know, and I have researched this, neither the EPA nor the USDA currently have any standards for any of the above terms.
So you could use any of them and not face fines or say a prison sentence, lol.

However... they are defined by public opinion and really to a business that is just as important.

Here is my advice:

Read the MSDS for all chems you use.
Look for the health rating. Anything a 1 is "friendly" enough to say "friendly"
Look for how it breaks down and how fast.
SH can be diluted easily.
It is safe enough for the EPA to approve it for drinking water after all.
Most of the products we use in our solutions are found in everyday items the client has in their home right now.

Rather than label myself as an "eco-friendly" roof cleaner I simply tell them the informed truth.

"Mr or Mrs Customer, the solution I use is a trade secret however the ingredients that make up the solution are found in products that would be very familiar to you. The main ingredient is sodium hypochlorite which is the same chemical at the same solution percentage (12.5%) that is used to treat city water, although we do use higher concentrations. We use enviromentally friendly methods to insure no harm comes to you, the roof, your plants, or pets."

Nice Pat...come sell for me for a week!! LOL

I guess its what ever you can market yourself as being

I do not offer it, but i have one ...always