Sweat is a liquid composed of dissolved solids such as water and chlorine, which is secreted from the sweat glands under the skin. The chemical structure of the sweat contains fragrance substances and certain chemicals such as 2-methylphenol (o-cresol) and 4-methylphenol (p-cresol). At the same time with sweating urea, uric acid, salt and other harmful substances in the human body are expelled. In short, sweat is made up of a number of chemicals and can create undesirable problems with leather textiles as well as with all textile products.

A number of alkaline or acidic solutions are used to measure sweat fastness. The purpose of these test studies is to determine how much sweat causes damage to leather products and the paint on them. In these tests, the sweat and temperature conditions of the human body are applied to the leather garments in the laboratory and it is monitored for any staining on the skin.

Tests are conducted by local and foreign accredited laboratories accredited laboratories to determine the sensitivity of the skin to sweat within the scope of specific tests. In these tests, national and international standards are taken into consideration. The standards for determining the fastness of sweat on the skin are as follows:

• TS EN ISO 11641 Leather - Color fastness tests - Color fastness to perspiration

This standard specifies a method for the determination of color fastness to perspiration during the processing of various skin types and at each step. This method is particularly applicable to dressing, gloves and lining leather to be used on the upper surfaces of shoes without lining.

• TS EN ISO 105-E04 Textiles - Color fastness tests - Part E04: Color fastness to sweat

This standard specifies the color changes caused by the perspiration of the human body in all textile products, including leather, and the level of contamination of other products by sweating.