These work together as a system and both need regular inspection and maintenance. Do not transport headwear in rear windows of vehicles. Inspect headwear before each use. Do not draw the chin strap over the brim or peak of the headwear. The shell is rigid and light, and is shaped to deflect falling objects.
Correct maintenance is important.
Inspect and replace a shell that shows signs of wear, scratches or gouges. Shells exposed to heat, sunlight and chemicals can become stiff or brittle. A visible pattern of tiny cracks may develop. Over time, weathered hats can become dull in colour or have a chalky appearance. Replace headwear when hairline cracks start to appear.