What pH range is considered alkaline?

The pH scale measures the acidity or alkalinity of a solution, ranging from 0 to 14. A pH of 7 is considered neutral, which means it is neither acidic nor alkaline. Values below 7 indicate acidity, while values above 7 indicate alkalinity.

The range that is recognized as alkaline begins at 7.1 and extends up to 14. Therefore, the correct choice includes all values from 7.1 up to the maximum of 14. This encompasses moderately alkaline to highly alkaline solutions, indicating their ability to neutralize acids.

Understanding the pH scale is crucial in hair coloring and chemical treatments, as it affects the hair's structure and how products interact with the hair and scalp. Alkaline products can help to open the hair cuticle, allowing for better penetration of color and other treatments.