Why might a helmet need to be decontaminated?

A helmet may need to be decontaminated primarily due to exposure to hazardous substances or contaminants. When a helmet is subjected to environments with chemicals, biological agents, or other harmful materials, these contaminants can adhere to the surface of the helmet. Decontamination is crucial to ensure that these substances do not pose a risk to the wearer, either by direct contact or through inhalation of particles that might remain on the helmet's surface.

Contaminated helmets can compromise both safety and health, as contaminants can lead to skin irritation or allergic reactions and might also degrade the integrity of the helmet over time. Proper decontamination procedures are essential in maintaining the safety standards required for personal protective equipment, ensuring that it continues to protect the user effectively.

While factors such as age, aesthetic damage, and flexibility do relate to the overall condition of the helmet, they do not necessitate decontamination in the same way that exposure to hazardous materials does. Decontamination specifically addresses the need for removing harmful substances that could jeopardize health, making it the most appropriate reason among the options provided.