What type of materials have a pH of 4?

Materials that have a pH of 4 are classified as acids. The pH scale, which ranges from 0 to 14, measures the acidity or alkalinity of a substance. A pH of 7 is considered neutral, while any value below 7 indicates acidity, with lower values representing stronger acids. A pH of 4 signifies that the material is indeed acidic, as it is below neutral. Examples of substances with a pH around 4 include certain fruit juices and vinegar, which contain organic acids. This understanding of pH levels is crucial for hazmat technicians, as handling and responding to acidic materials requires specific knowledge and safety protocols.