What type of foam is commonly used in helmets for impact absorption?

The commonly used foam in helmets for impact absorption is expanded polystyrene (EPS) foam. This material is specifically designed for safety applications due to its unique properties that allow it to effectively absorb and dissipate energy during an impact. When a helmet strikes a hard surface, the EPS foam compresses, which helps to reduce the force of the impact transmitted to the head. This compression process is crucial for preventing injuries, making EPS foam the preferred choice for many types of helmets, including those used in cycling, motorcycling, and various sports.

Other foam types, such as polyurethane, memory foam, and latex foam, serve different purposes. Polyurethane foam, while it can provide comfort, does not have the same impact absorption qualities as EPS. Memory foam is known for its comfort and ability to contour to shapes but lacks the necessary rigidity and energy absorption needed for safety in helmet applications. Latex foam is often used in cushioning applications but is not specifically designed for impact protection, making EPS superior for helmet use.