What materials other than foam might be used in helmet construction?

Using plastic outer shells and composite materials in helmet construction is essential for several reasons. These materials are selected for their ability to provide strength and durability while keeping the helmet lightweight. Plastic outer shells can absorb impact energy and help protect the wearer during incidents. Composite materials, often a combination of fiberglass, carbon fibers, and resin, enhance protective qualities through advanced engineering, allowing the helmet to meet safety standards while remaining comfortable.

Additionally, using materials beyond just foam allows for better overall performance in varying conditions. For example, while foam is critical for impact absorption, the outer shell is necessary for structural integrity and resistance to penetration and abrasion. This combination ensures that helmets not only protect the head effectively but also facilitate ease of movement and comfort for the wearer.

The other options do not fully align with the primary materials commonly used in helmets or their functional roles. Metal components can add weight and are not typically used for modern helmets, while leather is not a standard material for the main structure of safety helmets, often serving as a lining or accessory instead. Thus, the inclusion of plastic and composite materials is vital for creating effective and reliable head protection.