BHT is a short name for a chemical named butyl hydroxy toluene. In the textile industry, this material is used as an optical brightener for polyamide and protein-based fibers. Optical whiteners are auxiliaries which are increasingly consumed in the soap and detergent industry and are increasingly used in the textile industry. These organic components were found about fifty years ago and are used not only in the textile and detergent industries, but also in the plastics, paper and paint industries.

The areas and uses of optical brighteners by sectors are as follows: 40 percent in detergent blends, 30 percent in paper production, 5 percent in synthetic fibers and plastics, and 25 percent in textile production.

Optical whiteners are substances that absorb ultraviolet rays that are not visible to the human eye and reflect these rays by shifting them to the visible region of the eye. Optical brighteners are commercially known as bleaches, brighteners or brighteners.

Optical brighteners are used in the pre-finishing processes in the textile sector. Since very high whiteness is generally required in white products, in addition to bleaching, an additional optical whitening process is also performed.

Optical whitening agents are applied to textile products such as fibers, yarns, knitted or fabrics with or without a batch. Unlike dyes, this process can be applied in conjunction with bleaching or finishing processes.

The activity of optical brighteners is indicated by the “E” value. The optical density is measured at the wavelength at which the highest absorption occurs. This value should be at most E 1 / 1. In our country, the compounds generally used in the detergent industry are said to be 1 / 1 and 400 in the textile sector.

It is important to determine the BHT content of textile products in order to provide reliable products to consumers. These studies are carried out by authorized laboratories and these standards are based on the following standards:

• EKOTEKS 23