Manufacturers of corrosion resistant coatings and inhibitors find it difficult to replace their current formulations with green alternatives. Nevertheless, they are urged to meet the demands for environmentally-friendly products. The dilemma for suppliers is how to come up with green inhibitors that perform as well or even better than their toxic counterparts.

Conventional corrosion resistant coatings, particularly inhibitors, used to contain lead and chrome materials. When these heavy metals were removed from the formulation to reduce toxic contents, zinc phosphates were the most widely-used replacement. Although zinc-based inhibitors proved to perform well in many applications, it cannot totally replace chromate in water-based surface applications and fared poorly when exposed to salt-water. Nevertheless, zinc-based inhibitors are easy to use and handle. They are also cheap and good for a wide range of protective coating applications. Zinc-based inhibitors became very popular replacements for chrome-based inhibitors.

The challenge now for suppliers is how to develop zinc-free corrosion resistant coatings and inhibitors, because zinc phosphate is no longer allowed by newer and more stringent green labels and environmental standards. Compounding the challenge is the result of corrosion performance tests that showed that newly-developed non-zinc inhibitors are more inferior compared to zinc-based formulations.

There is a lot of work ahead for corrosion inhibitors manufacturers. To truly meet environmental requirements and get that coveted green label for their coatings, they must develop zinc-free inhibitors that maintain and even exceed the cost benefits, performance, and versatility of current products.

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