The safety of chemical cleaners depends on their composition. First of all, there are two kinds of chemical cleaning products – the abrasive/harsh ones and the eco-friendly type.
The abrasive types contain acids, phosphates, and other ingredients that might kill the plants and wildlife around the house if caution isn’t exercised. It’s normally recommended that you don’t rinse the product to prevent it from flowing down from the roof.
Again, the risk depends on the percentage of the active ingredients in the products. Around 5% is relatively safe.
The eco-friendly cleaners generally don’t pose a threat; they can even be rinsed.