Floor cleaners that are either high or low in pH may cause skin irritation when the human body comes in contact with them. The human body operates ideally at a close to neutral pH of 7.4. A cleaner with a higher pH than that is considered to be alkaline, while those lower than 7.4 are acidic.  Acidic cleaners can be very corrosive, so may also cause damage to your rubber gym flooring. They may also cause toxic fumes. Neutral pH cleaners are safer for the human body and for the environment.