Ironically the cheap helmets have foam that lasts almost forever, while the premium/expensive ones tend to turn to dust after a short time. The replacement liners costs a bomb.

If Malaysia has the incentive/tax rebate for helmets like they do in some countries, riders would be more happy to change their lid every couple of years. It's for safety anyway.

Supposedly it's because of safer (less toxicity) materials.

Could be, but inhaling that disintegrating dust doesn't seem that healthy too..