Corrosion is a type of degradation that occurs in metallic materials, causing loss of mass and altering the material's characteristics. This type of degradation occurs in the most diverse environments in our society, from household items to equipment components in companies. The most commonly used resource to reduce this type of damage is the use of corrosion inhibitors. However, most of these use zinc in their composition, which is extremely toxic both to the environment and to humans, even when administered in small quantities. Therefore, the study of natural corrosion inhibitors has been increasing. The substances responsible for inhibition present in plants are mainly proteins and tannins. Castor bean oil and the mucilage of aloe and ora-pro-nobis are extracts that contain these substances in large quantities and can therefore be effective in combating corrosion.