Tea staining happens when the surface of stainless steel becomes discoloured due to corrosion. One of the most common places for it to occur is near the sea. Tea staining can happen up to five kilometres from a beach with high levels of surf, or up to one kilometre from a beach with calm waters. Both wind and weather conditions play a decisive role in the extent of tea staining, and in some cases, it can occur up to 20 kilometres from the coast. The most important factor is proximity to a salt source; the shorter the distance, the more likely the chances of corrosion.

In addition to areas that are close to the sea, subtropical and high humidity climates also have a higher risk of contributing to tea staining.