In highly polluted urban environments, outdoor furniture faces constant assault from acid rain, particulate matter, sulfur dioxide, and nitrogen oxides. The most resilient material for such conditions is high-density polyethylene (HDPE), specifically recycled HDPE lumber. This material does not absorb moisture, resists chemical corrosion from pollutants, and never splits or cracks like wood. Its UV-stabilized formulation prevents fading even under smog-filtered sunlight.
For metal furniture, marine-grade stainless steel (316L) offers superior resistance to pitting and rust caused by acidic precipitation. Alternatively, powder-coated aluminum provides durability with a heavy-duty coating that withstands scratching and chemical erosion. Concrete reinforced with fiberglass is another option, but it is porous and requires sealants that may degrade over time.
Wood is not recommended, as even treated hardwoods like teak break down in high-pollution zones. Fabric components should use solution-dyed acrylic (e.g., Sunbrella) to resist fading and acid damage. For longevity in a polluted city, always choose materials with closed-cell structures and protective coatings, and consider modular designs for easy part replacement.