Corrosion inhibitors are additives in car wash chemicals that protect metal surfaces from chemical attack during washing. Given that active foams operate at high pH and acidic products at low pH, both extremes can corrode unprotected metals — making inhibitors essential for surface safety and equipment longevity.
What they protect:
- Vehicle surfaces — aluminium trim, chrome accents, steel body panels, and wheel alloys.
- Wash equipment — high-pressure lances, nozzles, dosing pumps, and stainless steel fittings.
- Infrastructure — drainage grates, concrete floors, and metal framing in wash bays.
Common types:
- Sodium metasilicate — forms a protective silicate film on aluminium and painted surfaces. Widely used in alkaline active foam formulations.
- Benzotriazole (BTA) — specifically protects copper and brass components.
- Phosphate esters — multi-metal protection, often used in acidic products.
Fortis Foam PRO includes a silicate-based corrosion inhibitor system that creates a temporary protective barrier during the wash cycle. This is especially important during touchless washing, where the chemical does all the work and contact time is longer than in manual methods.
For more on how chemistry interacts with paint, read our article on paint safety.