HLB stands for hydrophilic–lipophilic balance, a scale created by William C. Griffin (1949) to classify nonionic surfactants by how water-loving (hydrophilic) or oil-loving (lipophilic) they are. Formulators use HLB to quickly match surfactants to target oils and emulsion types, which is essential in cosmetics, cleaners, and water-based lubricants.
Quick takeaway: Lower HLB (≈1–9) favors W/O (water-in-oil); higher HLB (≈10–20) favors O/W (oil-in-water).
If you’re sourcing ingredients, explore BookChem surfactants here: BookChem Surfactants Catalog, or talk to our specialists via Contact BookChem.
Why Surfactants Need HLB
A surfactant has a hydrophilic head and a hydrophobic tail (which is lipophilic). This dual nature reduces interfacial tension and enables emulsification.
HLB correlates with solubility and emulsion behavior, helping predict whether a surfactant will stabilize O/W or W/O systems.
- Low HLB (more lipophilic) → better in oil, good for W/O
- High HLB (more hydrophilic) → better in water, good for O/W
Shop relevant emulsifiers:
- Nonionic Emulsifiers (browse category)
- HLB-Range Surfactant Blends (pre-balanced options)
How HLB Is Determined
The HLB scale runs from ~1 to 20. Values are calculated from structure or measured experimentally and are often provided by manufacturers.
- Experimental determination： Evaluate emulsion stability (e.g., creaming, coalescence, particle size).
- Theoretical calculation： Estimate from the surfactant’s functional groups and molecular makeup.
- Reference data： Published or supplier-reported HLB values.
Pro tip: When blending two or more surfactants, target an overall HLB that matches your oil phase requirement. If your oil needs HLB 12, combine surfactants so the weighted-average HLB ≈ 12.
Need a ready-to-use option? See BookChem balanced emulsifiers.
Understanding the HLB Scale
Typical guidance (rule-of-thumb ranges):
- HLB ≈ 1–9 → W/O emulsions (water dispersed in oil; thicker, richer feel; strong water resistance).
- HLB ≈ 10–20 → O/W emulsions (oil dispersed in water; lighter feel; easy cleanup).
Remember: Oil phases “require” a target HLB. Matching surfactant HLB to oil requirement improves kinetic stability and reduces phase separation.
How to Use HLB in Real Formulations
1) Lubricants & Metalworking Fluids
Water-based lubricants rely on stable O/W emulsions for cooling, lubricity, and tool life.
- Higher HLB surfactants often promote finer oil droplets, aiding cooling and cleanliness.
- Lower HLB can increase droplet size, biasing toward lubricity and film strength.
- Balance HLB to hit your foam, corrosion, EP/AW, and residue targets.
Formulation tip (O/W metalworking fluid):
- Primary O/W emulsifier: HLB ≈ 10–13
- Co-emulsifier/anti-foam tuning: Add a small portion of lower-HLB co-surfactant to improve boundary lubrication without sacrificing stability.
2) Cleaners & Detergents
HLB guides surfactant choice for soil removal, wetting, and fragrance solubilization.
- O/W cleaning systems typically favor higher HLB surfactants for wetting/solubilization.
- Hydrophobic additives (e.g., fragrances, waxes, silicones) may require specific HLB or co-surfactants to stay stable and clear.
- Car wash, hard-surface, and industrial cleaners often blend high-HLB with a touch of lower-HLB for balanced detergency and streak-free finish.
Step-By-Step: Picking a Surfactant with HLB
- Define emulsion type： O/W (most cleaners, many MWFs, lotions) or W/O (water-resistant creams, rust-preventives).
- Identify oil phase & target HLB： Each oil/wax/ester/silicone has a required HLB. Aim your blend at that number.
- Select primary emulsifier： Choose matching HLB.
- Fine-tune with co-surfactants： Adjust HLB, viscosity, foam, spreadability, and stability.
- Validate experimentally： Check droplet size, viscosity drift, phase separation, heat/cold stability, foam, corrosion, and application performance.
Need help? Contact BookChem for HLB matching support.
Common HLB Use-Cases (Cheat Sheet)
- O/W lotions, cleaners, MWF: HLB ≈ 10–15 (fine droplets, good wetting)
- W/O creams, moisture barriers, rust-preventives: HLB ≈ 4–8 (rich film, water resistance)
- Fragrance solubilization (O/W): Often HLB ≥ 12 plus a co-solvent
- Silicone or ester oils: Check required HLB; may need tailored blends
Explore options: BookChem Surfactants by Application
Troubleshooting with HLB
- Creaming/phase split in O/W: Increase overall HLB, raise surfactant level, or optimize droplet size.
- Poor lubrication film: Introduce a lower-HLB co-emulsifier to boost oil film.
- Foam too high: Blend in low-foaming surfactants or defoamers, adjust HLB downward slightly if appropriate.
- Fragrance haze: Use higher-HLB solubilizer and/or co-solvent, check HLB match.
HLB FAQs
Q1: Is HLB only for nonionic surfactants?
A: HLB was designed for nonionics, but formulators use it as a practical guide across systems. For ionics/amphoterics, treat HLB as an aid, not a strict rule.
Q2: Can I mix surfactants to hit a target HLB?
A: Yes. Weighted-average HLB is a common approach. Blend until your overall HLB meets the oil’s requirement and performance goals.
Q3: What if my oil’s required HLB is unknown?
A: Screen a small HLB ladder (e.g., 10, 12, 14 for O/W) and evaluate stability. BookChem can suggest starting points: Ask Us.
Q4: Does HLB guarantee long-term stability?
A: No—it’s a strong indicator, but full stability also depends on droplet size, rheology, electrolytes, temperature, and additives.
Key Takeaways
- HLB (1–20) expresses a surfactant’s hydrophilic vs. lipophilic balance.
- Low HLB (≈1–9) → W/O; High HLB (≈10–20) → O/W.
- Match surfactant HLB to the oil phase’s required HLB for better stability and performance.
- Lubricants and cleaners rely on HLB targeting to balance cooling vs. lubrication and wetting vs. solubilization.
- Blending surfactants lets you hit the target HLB and fine-tune foam, feel, and film.
Start sourcing now:
