Fine, white particles are blowing out of the cabin air ducts whenever the air conditioner or fan is turned on. My local BMW service center, Herb Chambers BMW of Boston, determined that the debris is flakes of aluminum from the deteriorated aluminum alloy fins of the AC evaporator coil and heater exchanger. The cabin air ducts were scoped and found to be intact with no intrusion of outside contaminants. The dealer determined that if not replaced, âthe A/C Evaporator will failâ¦â and quoted the cost of repairs at $5,286.18. As I am sure you are aware, aluminum is a neurotoxin when absorbed by the body. The science is well established and can be easily sourced using Google Scholar: https://scholar.google.com/scholar?hl=en&as_sdt=0%2C22&q=neurotoxicity+of+aluminum&oq=neuroto. The fine aluminum particles blowing from the heating and cooling system of my BMW have been absorbed into my eyes, mouth and airways, putting me at risk from internal exposure to aluminum. They have also rendered my BMW 335d unusable due to this health safety hazard. I filed a request for recourse with BMW of North America and was denied.