The inside of approved hard hats are marked with:

Approved hard hats are marked with essential information that ensures they meet safety standards and can be effectively used in various work environments. The markings typically include the manufacturer's name, which provides accountability and a warranty of quality; the applicable ANSI designation, which indicates that the hard hat complies with the American National Standards Institute standards for protective headgear; and the Class designation that specifies the type of protection offered, such as electrical resistance or impact protection.

This information is crucial for users to understand the capabilities and limitations of their hard hats, ensuring they select the proper head protection for their specific job requirements. Understanding this information also contributes to workplace safety by ensuring that employees wear head protection that meets the necessary safety standards, thus reducing the risk of injuries.

In contrast, while the date of manufacture and serial number may provide helpful information about the hard hat's production, they do not convey the critical safety standards and usage classifications that are essential for ensuring proper protection in the workplace. Other options may include contact details or incorrect markings that do not focus on the ANSI designation, which is vital in determining the hat’s approval and suitability for diverse working conditions.