Tearless Baby Shampoo has a measurement of 5.5 on the pH scale. Which makes it a safe solution. If your baby decides to lick the window, you will be comforted to know that he or she should be safe unless of an allergy or freaky uncontrollable element.
We all know that pH 'potential Hydrogen" is the measurement of a solution/substance to be acidic or alkaline (base). The scale goes from 1-14. So less than 7 is to be on the acid side and greater than 7 is to be alkaline. 7 is neutral, and what substance is that, pure water.
Common things that are acidic (less than 7); Lemon Juice 2.5, Vinegar 2.4-3, Tomatoes 4.3, Coffee 5, Clean Rain 5.8
Common things that are alkaline (more than 7); Tears 7.4 Sea Water 8, Baking Soda 8.5, Milk of Magnesia 10.5 , Ammonia 11, Bleach 12.5
When pH drops below about 2.5 or goes above 10 it is considered potentially hazardous. So think of it as you don't want to put lemon juice in your eye. Milk of Magnesia is slightly higher because it is used to counteract the stomach acidity.
Think about this commercial window cleaners can be any where from 10-14 on the pH scale and don't really look like they clean good.