Neutral Cleaners are water based cleaning chemicals with a pH (potential percentage of hydrogen) that is generally between 7-9.
Water based cleaning chemicals with pH between <1 and 8 are considered acidic. The lower the pH, the more acidic. Conversely, chemicals with pH between 8 and 15+ are alkaline. The higher the pH, the more alkaline.
pH ratings are logarithmic. Each unit rating is 10 times different than the unit next to it. For example, a chemical with a pH of 7 is 10 times more alkaline than a chemical with a pH of 6 and 100 times more alkaline than pH of 5.
Solvent based chemicals will not have a pH rating.