Optical brighteners are widely used in laundry detergents to help maintain the bright, clean appearance of white and light-colored fabrics.
However, selecting an optical brightener for a liquid detergent is not exactly the same as selecting one for a powder detergent.
The detergent format, concentration, manufacturing process, product stability and washing conditions can all influence the final result.
The correct optical brightener should therefore be selected according to the complete detergent formulation and production process, rather than simply choosing a familiar product name.
1. Start with the Detergent Format
The first question should be:
What type of detergent are you producing?
Common formats include:
Laundry powder
Standard liquid detergent
Concentrated liquid detergent
Single-dose / unit-dose detergent
Commercial laundry detergent
CBS-type optical brighteners are commercially used across both liquid and powder detergents, including highly concentrated liquids and single-dose products.
However, the formulation requirements of these products are very different.
A suitable optical brightener therefore needs to work not only during the wash cycle but also during the manufacturing and storage of the detergent itself.
2. Liquid Detergents Require Good Formulation Compatibility
For liquid detergents, one of the most important questions is:
Can the optical brightener remain properly incorporated in the formulation during storage?
Liquid detergents may contain:
Surfactants
Builders
Enzymes
Polymers
Fragrance
Colorants
Electrolytes
Preservatives
Other functional ingredients
The optical brightener should therefore be evaluated in the complete liquid formulation.
Important practical considerations include:
Solubility + Compatibility + Uniformity + Storage Stability + Whitening Performance
A product that performs well in a simple laboratory solution may behave differently in a concentrated detergent formulation.
3. Does a Liquid Detergent Require a Liquid Optical Brightener?
Not necessarily.
This is an important distinction.
The physical form in which the optical brightener is supplied is not the same as the final detergent format in which it can be used.
Commercial detergent optical brighteners are available as:
Free-flowing granules
Stable aqueous dispersions
Clear solutions
to meet different formulation and production requirements.
For example, commercial CBS-X is available as a granular product while CBS chemistry is also used in liquid detergent formulations.
Therefore, the correct question is not:
“Is the optical brightener a powder, granule or liquid?”
but:
“Can this grade be incorporated effectively into my detergent formulation?”
4. Solubility Is Especially Important in Liquid Detergents
Poor incorporation of an optical brightener may contribute to:
Sediment
Undissolved material
Uneven product appearance
Inconsistent dosing
Reduced whitening efficiency
For liquid detergent formulations, the formulator should evaluate the optical brightener under the actual production conditions.
Relevant factors may include:
Water content
Product concentration
Mixing conditions
Addition sequence
Temperature
Surfactant system
Other formulation ingredients
Commercial detergent optical brightener ranges emphasize high solubility specifically because incorporation into different home-care formulations is an important performance requirement.
5. Concentrated Liquid Detergents Need Additional Attention
Concentrated liquids contain less water and higher levels of active ingredients than conventional liquid detergents.
This creates a more demanding formulation environment.
When selecting an optical brightener for a concentrated liquid, evaluate:
Can it be incorporated properly?
Does the detergent remain uniform during storage?
Does the optical brightener remain available during the wash?
Does the finished detergent maintain acceptable appearance and stability?
CBS optical brighteners are commercially used in highly concentrated liquid detergent systems, showing that suitable grades can be formulated into these modern product formats.
However, the actual formulation still needs to be tested.
6. Single-Dose Detergents Have Different Formulation Requirements
Single-dose detergents are another increasingly concentrated application.
Because the formulation is compact and highly concentrated, manufacturers need to pay particular attention to ingredient compatibility and stability.
The optical brightener should be evaluated together with the complete system rather than treated as an isolated additive.
Commercial CBS optical brighteners are specifically used in single-dose detergent formats.
For these systems, laboratory stability testing is particularly important before full-scale production.
7. Powder Detergents Have Different Handling Priorities
For powder detergent manufacturers, formulation stability in a liquid phase is generally less important than raw-material handling and uniform distribution in the detergent powder.
Important considerations may include:
Particle form
Flowability
Dust generation
Dosing accuracy
Mixing uniformity
Distribution throughout the detergent
Storage stability
Free-flowing granular optical brighteners can be useful where cleaner handling and lower dust generation are production priorities. Commercial detergent OBA ranges include free-flowing granular grades specifically suited to industrial formulation needs.
The correct physical form should therefore be matched to the detergent plant’s actual equipment and dosing system.
8. Powder or Granules Does Not Determine Whitening Strength
A granular optical brightener is not automatically stronger than a powder grade.
Likewise, a finer powder is not automatically more effective.
Whitening performance should be evaluated according to factors such as:
Active content
Optical efficiency
Product specification
Required dosage
Formulation compatibility
Final washing performance
Physical form mainly influences handling and incorporation.
The actual performance comparison should be made under equivalent detergent and washing conditions.
9. Low-Temperature Washing Should Be Considered
Modern laundry detergents increasingly need to perform effectively at lower washing temperatures.
This matters because the detergent formulation must still deliver acceptable fabric appearance under shorter and cooler wash cycles.
CBS optical brighteners are commercially used in detergent systems designed to provide whitening performance even at low wash temperatures and short wash cycles.
BASF has also demonstrated liquid detergent formulations combining CBS-X with enzymes and other performance ingredients for cold-wash applications.
Therefore, when evaluating an optical brightener, manufacturers should test it under the actual washing conditions expected in the target market, not only under ideal laboratory conditions.
10. Optical Brightener Is Only One Part of Long-Term Fabric Whiteness
Another important point is that optical brightening is not the only mechanism responsible for maintaining white fabrics.
Long-term fabric appearance can also be affected by:
Soil redeposition
Dye transfer
Fabric greying
Washing conditions
Detergent performance
BASF describes long-lasting whiteness as a combination of optical brightening, dye-transfer inhibition and anti-redeposition/anti-greying performance.
This means that if fabrics become gray or dull after repeated washing, simply increasing the optical brightener dosage may not solve the complete problem.
The entire detergent performance system should be reviewed.
11. More Optical Brightener Does Not Always Mean Better Results
A common formulation reaction is:
The whitening effect is not strong enough, so increase the dosage.
However, optical brightener dosage should be optimized rather than increased automatically.
The effective level depends on:
Detergent format
Optical brightener grade
Active concentration
Fabric type
Wash temperature
Dosage of detergent in the wash
Other detergent ingredients
Required whitening performance
Once sufficient whitening performance has been achieved, additional optical brightener may increase formulation cost without providing proportional value.
The target should therefore be:
Required whitening performance at an optimized dosage
rather than maximum optical brightener concentration.
12. Do Not Compare Products Only by Price per Kilogram
Two optical brighteners may have different:
Active content
Product form
Solubility
Optical efficiency
Recommended dosage
Handling characteristics
Formulation compatibility
Therefore, comparing only the purchase price can be misleading.
A more useful comparison is:
Product Price + Active Content + Required Dosage + Formulation Stability + Washing Performance
The important question is:
What is the real optical brightener cost per ton of detergent at the required performance level?
This provides a better basis for purchasing decisions.
13. Liquid vs Powder Detergent: What Should You Focus On?
For Liquid Detergents
Focus particularly on:
Solubility + Formulation Compatibility + Storage Stability + Concentration + Whitening Performance
For Powder Detergents
Focus particularly on:
Flowability + Dust Control + Dosing + Mixing Uniformity + Product Specification + Whitening Performance
For Concentrated Liquids and Single-Dose Products
Pay additional attention to:
Ingredient Compatibility + High-Concentration Stability + Incorporation + Final Product Uniformity
The optical brightener should always be selected according to the actual detergent format.
14. How Should You Compare Two Optical Brighteners?
When comparing different grades, keep the main test conditions consistent.
Use the same:
Detergent formulation
Detergent dosage
Fabric type
Water conditions
Wash temperature
Wash cycle
Drying conditions
Then evaluate:
Formulation Stability
Does the optical brightener remain properly incorporated in the detergent?
Whitening Performance
Does the washed fabric reach the required visual whiteness?
Shade
Is the final white appearance appropriate?
Low-Temperature Performance
Does the product still perform under cooler washing conditions?
Repeated-Wash Performance
Does the detergent continue to support a bright fabric appearance over repeated wash cycles?
Required Dosage
How much optical brightener is needed?
Overall Cost
Which grade provides the most efficient result in the finished detergent?
15. A Practical Selection Process
A practical approach can follow these steps.
Step 1 — Identify the Detergent Format
Determine whether the product is powder, conventional liquid, concentrated liquid or single-dose.
Step 2 — Define the Manufacturing Process
Consider mixing, dosing, dissolution and handling requirements.
Step 3 — Select a Suitable Optical Brightener Form
Evaluate whether granule, powder, dispersion or solution is most practical for the production system.
Step 4 — Check Formulation Compatibility
For liquid formulations in particular, confirm that the optical brightener remains properly incorporated.
Step 5 — Define the Target Washing Conditions
Consider:
Wash temperature
Cycle length
Detergent dosage
Target fabric types
Step 6 — Test Several Dosage Levels
Keep the rest of the detergent formulation unchanged.
Step 7 — Evaluate the Finished Detergent
Check appearance, uniformity and storage stability.
Step 8 — Perform Washing Tests
Compare the whitening result on actual fabrics.
Step 9 — Calculate Application Cost
Compare performance at the required dosage rather than product price alone.
What Is the Best Optical Brightener for Detergents?
There is no single optical brightener grade that is best for every laundry detergent.
The correct choice depends on:
Detergent Format + Product Form + Solubility + Formulation Compatibility + Wash Conditions + Whitening Performance + Dosage + Cost
For liquid detergents, incorporation and formulation stability are particularly important.
For powder detergents, handling, flowability and uniform distribution can become more important.
For highly concentrated liquids and single-dose formats, the complete formulation environment should be carefully evaluated.
The most suitable optical brightener is the one that provides consistent whitening performance while fitting the manufacturer’s formulation and production process.
Need Help Choosing an Optical Brightener for Detergents?
If you are developing or optimizing a laundry detergent, tell us your detergent format, current optical brightener, formulation type, washing conditions and target whitening performance.
Blue Dolphin can help you evaluate suitable optical brightener options for powder, liquid, concentrated and single-dose detergent formulations.
Post time: Aug-14-2026