In the chemical field, acids are hydrogen compounds and, if combined with water, produce hydrogen ions. These hydrogen ions give the solution acidic properties. Most foods contain acid. Citric acid is primarily in lemon and acetic acid is in vinegar. Different acids have different tastes. There are mainly two types of acids. Inorganic acids are made of minerals and non-metallic materials. Sulfuric acid, nitric acid, hydrochloric acid and phosphoric acid are included in this group. They are used in the production of fertilizers, plastics, fibers and paints. Organic acids are acidic carbon compounds produced by plants, animals and humans. Harmful organic acids are used to taste foods. They can be found in living organisms or they can be obtained naturally. Many artificial organic acids have been produced to replace antibiotics, especially after the prohibition of the use of various hormones in animal nutrition.

Given these properties of acids, it is clear that there will be many aspects of acid dripping on textile products. For example, in this case, cleaning with acid-containing substances may result in thinning of the fibers and discoloration. It does not remove stains, especially on synthetic or permanent printed fabrics, and can also cause wrinkles on the fabric surface.

Acid drip fastness is used to determine the degree of color loss of printed or dyed textile products in contact with acid.

In the case of acid drip tests carried out by accredited laboratories, color fastness tests are performed in accordance with the following standards:

• TS EN ISO 105-E05 Textiles - Color fastness tests - Part E05: Color fastness to staining - Acid

This standard has been developed to determine the strength of the fabric against the dilute solutions of all kinds of organic and mineral acids that can affect the color of any textile product.