The three numbers that define a grade
LABSA (linear alkyl benzene sulphonic acid, CAS 27176-87-0) is the primary surfactant in most detergent manufacture. It is supplied as a brown to dark amber viscous liquid, and the commercial grades are defined by how much of it is actually surfactant.
| Parameter | LABSA 96% | LABSA 90% |
|---|---|---|
| Active matter | ≥96% | ≥90% |
| Free sulfuric acid | ≤1.5% | ≤4.0% |
| Colour (Klett) | ≤20 | ≤40 |
| Typical use | Premium powders, liquid detergents | Budget powder detergents |
| Dosage needed | Lower | Higher for equivalent performance |
- Active matter is what you are actually buying — compare quotations on cost per kilogram of active matter, not per kilogram of slurry
- Free sulfuric acid is dead weight that consumes extra caustic soda during neutralisation and adds sodium sulphate to the finished product
- Klett colour is the parameter buyers most often ignore and most often regret; it carries straight through into the appearance of the finished detergent
- For a clear or light-coloured liquid detergent, colour is not a preference — it is a hard requirement
Key properties
| Property | Value |
|---|---|
| Chemical name | Linear alkyl benzene sulphonic acid |
| CAS number | 27176-87-0 |
| Alkyl chain length | C10 to C14, linear |
| Appearance | Brown to dark amber viscous liquid or paste |
| pH (1% solution) | 1.5–2.5 — strongly acidic |
| Density at 20 °C | 1.05–1.10 g/cm³ |
The chain being linear matters environmentally rather than technically — linear alkylbenzene sulphonates biodegrade, whereas the branched material they replaced did not. If a quotation is unusually cheap, confirm it is genuinely linear.
Neutralisation is where the money is
LABSA is an acid and has no detergency until it is neutralised to its sodium salt. That step is normally done in-house with caustic soda, and it is where free sulfuric acid content translates directly into cost.
- Free sulfuric acid consumes caustic soda without producing any surfactant — every kilogram of it is caustic wasted and sodium sulphate gained
- Neutralisation is strongly exothermic; control the temperature or you will darken the product and degrade the surfactant
- Target pH is typically 7–8 for powders and slightly higher for liquids; overshooting wastes caustic and can hydrolyse the product
- A 90% grade needs both more slurry and more caustic for the same active delivery, so the price gap against 96% is smaller than it looks
- Calculate cost per kilogram of neutralised active surfactant, including the caustic, when comparing grades
Where it sits in a formulation
| Ingredient | Typical share | Role |
|---|---|---|
| LABSA, neutralised to LAS | 8–20% | Primary surfactant |
| SLES | 5–12% | Secondary surfactant and foam booster |
| Caustic soda | As required | Neutralisation and pH adjustment |
| Salt | 1–3% | Viscosity control |
| Fragrance | 0.2–1% | Odour |
| Preservative | 0.1–0.2% | Shelf life |
| Water | Balance | Carrier |
Soda ash and sodium sulphate normally appear alongside as builder and filler in powder formulations. A detergent plant buying LABSA is usually buying caustic soda, soda ash and sodium sulphate on the same schedule, which is worth consolidating onto one enquiry.
Storage and handling
- Highly viscous, and viscosity rises sharply as temperature falls — winter deliveries in northern Pakistan can be difficult to pump
- Store between roughly 15 °C and 40 °C; heated or insulated storage pays for itself if you run through winter
- Strongly acidic and corrosive — suitable materials are HDPE, FRP, PTFE and rubber-lined steel
- Avoid carbon steel and stainless steel; iron pickup darkens the product and shows in the finished detergent
- Prolonged storage at elevated temperature darkens LABSA, so buy to a schedule rather than stockpiling in a hot warehouse
- Full face shield, chemical gloves and apron for handling; it causes severe skin and eye burns
What to put on the RFQ
- Active matter minimum, free sulfuric acid maximum and Klett colour maximum — all three
- Confirmation that the material is linear alkylbenzene sulphonate rather than branched
- Quantity per delivery and annual volume, ideally expressed in tonnes of active matter
- Pack — drum, IBC or road tanker — and whether heated transfer is available on delivery
- Delivery city and whether your store is heated or insulated for winter
- Documentation — batch COA reporting active matter, free acid and colour with measured values
What drives the price
- Linear alkylbenzene (LAB) feedstock pricing, which follows benzene and kerosene-range paraffins
- Sulphur and sulfuric acid costs for the sulphonation step
- Grade, with 96% carrying a premium that is partly offset by lower dosage and lower caustic consumption
- Colour specification, since achieving low Klett requires better process control and sometimes bleaching
- Pack format and heated transport where required
- Exchange rate and duty, since Pakistan is supplied by a mix of domestic sulphonation and import
Sourcing considerations in Pakistan
- Pakistan has domestic sulphonation capacity as well as imports, so both routes are available — confirm which you are quoted where colour consistency matters
- It moves as a corrosive material and needs appropriate transport
- For a detergent plant, consolidating LABSA with caustic soda, soda ash and sodium sulphate on one enquiry usually improves pricing and simplifies scheduling
- Ask for a retained sample against each delivery if colour consistency has been a problem, so batches can be compared objectively