Commercially available condenser unit cleaners that are approved by the government are safe to use. If the solution is approved by the U.S.D.A, it does not contain any constituents that may be toxic to humans and the environment.
You need to be careful when purchasing an AC cleaning product. There are several ac cleaners on the market which makes it easy to get the wrong one. Always purchase the best coil cleaner for AC that is approved by the authorities.