Sodium Lauryl Ether Sulfate (SLES) is one of the most widely used anionic surfactants in the world. It is a key ingredient in shampoos, body washes, liquid detergents, and industrial cleaners.
If you purchase SLES, you will face a basic question: Should you buy 70% or 28%?
Many buyers choose based on price per metric ton alone. This is a mistake. The real question is which grade delivers the lowest cost per unit of active surfactant across your entire supply chain.
This guide explains the differences from a factory perspective. It covers active matter cost, logistics, handling, and application fit.
1. What Is the Difference?
SLES 70% and SLES 28% contain the same surfactant chemistry. The only difference is the amount of water.
| Feature | SLES 70% | SLES 28% |
|---|---|---|
| Active Matter | 70% ± 2% | 28% ± 1% |
| Appearance | White to pale yellow paste | Colorless to yellowish liquid |
| Water Content | ~30% | ~72% |
| Viscosity | High (gel-like) | Low (pourable) |
SLES 70% is a concentrated paste. SLES 28% is pre-diluted. Both grades can deliver the same cleaning performance when adjusted to the same active matter level.
2. Cost: The Active Matter Calculation
Price per metric ton is misleading. You must compare cost per kilogram of active surfactant.
Here is an illustrative example:
| Calculation | SLES 70% | SLES 28% |
|---|---|---|
| Price per metric ton (example) | $1,800 | $900 |
| Active matter per ton | 700 kg | 280 kg |
| Cost per kg of active matter | $2.57 | $3.21 |
In this example, the 70% grade delivers more than twice the active surfactant per metric ton compared to the 28% grade. The concentrated grade gives you a 20% lower cost per unit of active ingredient.
Important: These prices are illustrative only. Actual market prices vary by region, volume, and timing. Request a current quote from your supplier.
3. Logistics: Shipping and Storage
SLES 70% contains 2.5 times more active ingredient per kilogram than SLES 28%.
When you buy 28%, you are paying to ship, store, and handle a product that is 72% water.
| Logistics Factor | SLES 70% | SLES 28% |
|---|---|---|
| Active matter per container | Higher | Lower |
| Freight cost per kg of active | Lower | Higher |
| Storage space required | Less | More |
For international shipping, 70% is the preferred export grade. It reduces shipping volume significantly. Importing 70% in full container loads (FCL) can cut ocean freight costs per ton of active surfactant.
The exact advantage depends on packaging (IBC, drums, ISO tanks), container loading capacity, and shipping terms (FOB, CIF).
4. Handling and Processing
SLES 70% Requires More Care
SLES 70% is a high-viscosity paste. It requires proper equipment to handle.
Two golden rules apply when diluting 70% SLES:
- Add the concentrate to water – never the other way around.
- Avoid exceeding approximately 27% concentration during dilution – exceeding this can form a highly viscous gel that is difficult to process.
The dilution process works best with high-shear mixing equipment. A high-shear inline mixer ensures uniform mixing in a single pass.
Temperature also affects viscosity. A process temperature range of 25–35°C (75–95°F) is often recommended for manageable viscosity during dilution. In colder conditions, warming the material may help with pumping.
SLES 28% Is Ready to Use
SLES 28% is a low-viscosity liquid. It can be added directly to formulations with standard agitation.
- No dilution equipment is required.
- No heating is needed.
- No special mixing is necessary.
This simplicity makes 28% attractive for smaller operations or facilities without high-shear mixers.
5. Which Grade Should You Choose?
The right choice depends on three factors: production scale, equipment capability, and formulation needs.
Choose SLES 70% If:
- You have high-shear mixing equipment
- You have dilution tanks and the expertise to handle concentrated paste
- You purchase in large volumes (economies of scale justify the equipment)
- You want to minimize freight and storage costs
- You need formulation flexibility for different final concentrations
Choose SLES 28% If:
- You operate on a smaller scale
- You lack dilution equipment or heating systems
- You value ease of use – pour and go
- You run small-batch, multi-product production lines
- You need precise, low-concentration dosing for specific applications
A Note on Formulation Performance
Some sources suggest 70% provides superior thickening power. However, thickening in the final formulation depends primarily on the salt curve (NaCl response) and the overall formulation system – not simply on the incoming concentration. Always test your specific formulation.
6. Summary Decision Guide
| Your Situation | Recommended Grade | Why |
|---|---|---|
| Large factory with dilution equipment | 70% | Lowest active cost, best logistics |
| Large factory without dilution capability | 28% | Equipment gap makes 70% impractical |
| Small to medium producer | 28% | Simpler operations, no capital investment |
| Exporting long distances | 70% | Minimize freight cost per active ton |
| Multiple small-batch formulations | 28% | Faster changeovers, less cleaning |
The “large” vs “small” threshold varies by your specific operation. Factors include your annual volume, available equipment, labor costs, and freight rates. There is no universal number.
7. Final Takeaway
SLES 70% and 28% are the same chemical. The difference is concentration.
70% wins on cost per active kg and logistics efficiency. But it requires the right equipment and expertise.
28% wins on simplicity and convenience. But you pay a premium for the water you are shipping and storing.
The best choice depends on your factory’s capabilities and your supply chain costs.
Need Help Deciding?
HOO CHEMTEC is a direct SLES manufacturer with export-grade 70% and ready-to-use 28% grades. We can help you calculate the total landed cost for your specific situation.
Disclaimer: Price examples in this article are for illustrative purposes only. Actual prices vary by market conditions, volume, and region. Always verify current pricing with your supplier. Handling recommendations are general guidance; consult your equipment manufacturer and safety data sheet (SDS) for specific operating procedures.
