What are optical brighteners in laundry detergent？

Optical brighteners also known as fluorescent agents, optical brightening agents (OBAS), fluorescent brightening agents (FBAs), fluorescent brightener, or fluorescent whitening agents (FWAs) are a kind of fluorescent dyes, or white dyes, and also a complex organic compound. Its characteristic is that it can absorb incident light and produce fluorescence, so that the dyed material can obtain a glittering effect similar to fluorspar, and the material seen by the naked eye is very white.

Its characteristic is that it can absorb incident light to produce fluorescence, so that the dyed material can obtain a glittering effect similar to fluorspar, so that the material seen by the naked eye is very white and achieve the whitening effect. Its function is to transform the invisible ultraviolet radiation absorbed by the product into purple blue fluorescent radiation, complement each other with the original yellow radiation into white light, and improve the whiteness of the product under sunlight.

Fluorescent brighteners have been widely used in textile, papermaking, washing powder, soap, rubber, plastics, pigments and paints.

How Do Optical Brighteners Work?

Optical brighteners function by leveraging the principles of fluorescence. When exposed to UV light, these compounds absorb invisible UV radiation and emit visible blue light. This blue light offsets the yellowish tinge that may be present on the fabric, creating a perception of increased whiteness and brightness. Here’s a step-by-step breakdown of the process:

Absorption: Optical brighteners absorb UV light in the range of 300 to 400 nanometers.
Emission: The absorbed energy is re-emitted as visible blue light, typically in the range of 420 to 470 nanometers.
Perception: The emitted blue light neutralizes any yellowish or dull appearance on the fabric, making it look whiter and brighter.

Specifications Table

Optical Brightener	Chemical Composition	UV Absorption Range (nm)	Emission Range (nm)	Compatibility	Solubility	Usage Concentration	Stability
CBS-X	Disodium 4,4'-bis(2-sulfostyryl) biphenyl	340-360	420-440	Anionic detergents, neutral pH	Water-soluble	0.05 - 0.2%	Stable in water, sensitive to acids
Tinopal DMS	4,4'-bis[(4-anilino-6-morpholino-1,3,5-triazin-2-yl)amino] stilbene-2,2'-disulfonic acid disodium salt	350-370	430-460	Suitable for all detergent types	Water-soluble	0.1 - 0.3%	Stable in high temperatures
Tinopal CBS	4,4'-bis(2-sulfostyryl) biphenyl	340-360	420-440	Compatible with anionic surfactants	Water-soluble	0.05 - 0.2%	Good stability in high pH
Blankophor HRH	Sodium salt of distyrylbiphenyl	340-370	430-450	Effective in all pH conditions	Water-soluble	0.05 - 0.15%	Excellent chemical stability
Leucophor BSB	Stilbene derivative	340-365	430-450	Suitable for anionic and nonionic surfactants	Water-soluble	0.05 - 0.2%	Stable in light and water

Are optical brighteners harmful to human body?

Scientists have studied the possible toxicity of optical brighteners to human body from many angles. It is concluded that the fluorescent brightener in detergent is safe for human body.

Reports about optical brighteners in washing powder / liquid always worry everyone. Then, is there really optical brighteners in washing powder / liquid? What are the effects of fluorescent agents on human body? What scientific methods can we accurately distinguish whether it contains fluorescent agents? With these questions, listen to the answers of chemical experts——

1. Is there really an optical brightener in the washing powder / liquid?

Fluorescent brightener or optical brightener is a compound with high quantum efficiency. It can effectively whiten the white or white matrix (such as textiles, paper, plastics and coatings) in the order of one million to one hundred thousandth of a million.
It can absorb ultraviolet light with a wavelength of about 340 ~ 380nm and emit blue light with a wavelength of about 400 ~ 450nm. It can effectively make up for the yellowing of white substances caused by blue light defects, and visually significantly improve the whiteness and brightness of white substances.
The optical brightener itself is colorless or light yellow (green). The brightener has a cyclic conjugate system in chemical structure, such as stilbene derivatives and phenylpyrazoline derivatives. The optical brightener that has been industrialized has 15 basic structural types and nearly 400 chemical structures. The largest optical brighteners in China are VBL, CXT and liquid brighteners for papermaking.
Optical brighteners are generally divided into two categories, one is water-soluble brightener, the other is water-insoluble brightener. The former can be used as a whitening agent for paper, coatings, washing powder and washing liquid. The latter can be used for whitening of chemical fiber and plastics. Therefore, the washing powder and liquid in the laundry contain water-soluble optical brighteners.

2. If there is optical whitening agent in laundry detergent, how harmful is it to your body?

With the wide use of optical brighteners, people begin to worry about whether optical brighteners will affect human health. Scientists' research is also gradually inclined to this field.

Therefore, aiming at the possible toxicity of optical brighteners to human body, scientists have conducted research from multiple angles, including the dose of possible toxicity, the side effects of long-term exposure, sensitization and so on.

In 1999, the European Chemical Industry Association (Cefic) and the European soap and Detergent Association (aise) launched the "human and environmental risk assessment of household cleaning products (Hera)" project. The results show that the optical brightener for laundry detergent is safe for long-term use in detergent and will not have a negative impact on human body and environment.
In October 2007, the Japan soap and Detergent Industry Association (JSDA) released the "Risk assessment results of the impact of optical brighteners on human health and the environment" report. The research conclusion is that optical brighteners for laundry detergents are safe for human body and the environment.
Since the 1970s, many researchers in China have also done a lot of research on the safety of fluorescent brighteners, and there is "is synthetic detergent toxic?" The publication of the book affirmed the safety of fluorescent brighteners for detergents.
In 2008, China Light Industry Federation issued the enterprise standard of optical brightener for detergent. Expert demonstration meeting on the subject of "Health risk assessment guidelines for washing products raw materials" held in April 2016. After discussion, experts also determined that the fluorescent whitening agent in washing products is safe for consumers and can be used safely.

3. How to identify products with optical brighteners?

When irradiated with a purple light lamp (purple light 365), the daily necessities containing fluorescent agent are bright blue, and the ones that do not contain are darker purple.

Baby clothes, diapers, and facial mask try to avoid buying products containing fluorescent agents. It is generally no problem to purchase regular products from regular channels through daily channels.

4.What are the common optical brighteners in detergent and detergent?

Stilbene biphenyls (such as CBS) and BIS triazine aminostilbenes (such as BLF, FBM, etc.).

Fluorescent brightener fbm-el is a special brightener for liquid detergent

Fluorescent brightener FBM is an important fine chemical product, which is widely used in various liquid detergents to increase the whiteness and color brightness of washed fabrics. Generally, the addition amount is in the proportion of 0.1-0.4%. The recommended dosage of FBM in detergent is no more than. Due to the technical requirements of detergent formula, fluorescent brightener for detergent can only be added in a small amount. If it is added in excess, it will not increase the washing effect, but turn the clothes yellow.

Fluorescent brightener FBM is a kind of functional assistant in laundry detergent, which has high quantum efficiency. It is also added in a small amount in laundry products. The whitening agent FBM is different from chemical redox bleaching. It can absorb ultraviolet rays and emit blue fluorescence, which is superimposed with the yellow light of the clothing itself to form white light, so that the clothing becomes whiter and brighter visually.

Fluorescent brightener BLF in laundry detergent

The application of new optical brightener BLF (heliya BLF) and three common traditional fluorescent brighteners (31#, 33# and CBS-X) in phosphorus free and phosphorus containing ordinary washing powder was studied from the aspects of powder whiteness, fabric whiteness and cost. The experimental results show that the powder whiteness, fabric whiteness and Fabric whitening is superior to the three commonly used traditional fluorescent brighteners in both aspects. The cost increase of washing powder is 31#, 33# equivalent, but much lower than cbs-x. it has a high performance price ratio, significantly improves the decontamination value of washing powder, and is an ideal upgrading product of traditional brighteners. At the same time, Helia BLF can be mixed into liquid detergent in high concentration, with transparent appearance, no precipitation and turbidity at low temperature, It fills the gap of Brightener for liquid washing in China

Fluorescent brightener CBS-X is added to the washing liquid.

This brightener is specially developed for washing products

Nickname: 2,2'-((1,1'-biphenyl)-4,4'-diyldi-2,1-ethenediyl)bis-benzenesulfonicaci

2,2'-([1,1'-biphenyl]-4,4'-diyldi-2,1-ethenediyl)bis-benzenesulfonicacidi

2,2'-(4,4'-biphenylylenedivinylene)di-benzenesulfonicacidisodiumsalt

Benzenesulfonicacid,2,2'-[(1,1'-biphenyl)-4,4'-diyldi-2,1-ethenediyl]bis-,disodiumsalt

disodium4,4'-bis(2-sulfostyryl)biphenyl

tinopalcbs

fluorescent brightener cbs-x

disodium 2,2'-[biphenyl-4,4'-diyldi(E)ethene-2,1-diyl]dibenzenesulfonate

disodium 2,2'-[biphenyl-4,4'-diyldi(Z)ethene-2,1-diyl]dibenzenesulfonate

4,4'-Bis-(2-sulfostyryl)-biphenyl disodium salt

Optical Brightening Agent CBS-X for Synthetic detergent

It is mainly used for whitening synthetic detergent, soap and soap, as well as cotton, hemp, nylon wool and paper; Suitable for whitening of cotton, polyester cotton blended fabrics and one bath whitening of cotton blended fabrics; Widely used in detergent, bleaching and dyeing, papermaking, dyes and other industries

Pros and Cons of Using Optical Brighteners

Pros

Enhanced Whiteness and Brightness:

Optical brighteners give fabrics a visually appealing appearance, making them look newer and cleaner.

Increased Perception of Cleanliness:

They can make clothes appear cleaner, even if there are residual stains, as the emitted blue light masks yellowing or dulling.

Versatile Application:

Suitable for various types of detergents, including liquid, powder, and tablets.

Cost-Effective:

Only a small amount is needed to achieve the desired effect, making them cost-effective for manufacturers.

Cons

Environmental Impact:

Optical brighteners are not readily biodegradable and can accumulate in aquatic ecosystems, potentially affecting aquatic life.

Skin Sensitivity:

Some individuals may experience allergic reactions or skin irritation due to the chemicals in optical brighteners.

Fabric Compatibility:

Not all fabrics benefit from optical brighteners. They may not be effective on dark-colored fabrics and can sometimes cause a bluish tint on certain materials.