Most previous studies have shown that there is a critical concentration of chloride ions (Ccrit). Once this concentration is exceeded, they can diffuse and degrade the passive film even without altering the overall pH. However, other studies indicated that the ratio of [Cl -]/[OH - ] is more relevant for corrosion. On the contrary, more recent studies demonstrated that such threshold limits can be significantly altered by environmental and exposure conditions, reducing their scientific significance. As a result, further investigations in this direction are warranted.