When you receive your BBQ Rangehood no matter what grade Stainless Steel it is made off Spray a coating of Vegetable Oil over every part of the Rangehood including the Filters. This will add some protection to your Rangehood from CHLORIDES that are in the air. This should also be done after you have cleaned your rangehood with very mild detergent infused clean warm water & rinsed off with cold water & polishing cloth.