Safe, Compliant & Sustainable Chemistry
| HS Code | 240437 |
| Chemical Name | Sodium Lauryl Ether Sulfate (SLES) |
| Cas Number | 9004-82-4 |
| Molecular Formula | CH3(CH2)11(OCH2CH2)nOSO3Na (n typically 1-3) |
| Appearance | Clear to slightly hazy viscous liquid |
| Active Matter Content | 70% (typically 70 ± 2%) |
| Ph 1 Aqueous Solution | 6.5 - 8.5 |
| Color Apha | 20 max |
| Viscosity At 25 C | 500 - 1500 mPa·s |
| Sodium Sulfate Content | 1.5% max |
| Unsulfated Matter Content | 2.0% max |
| Water Content | Approximately 30% |
| Solubility | Fully soluble in water forming a clear solution |
| Chemical Classification | Anionic surfactant |
As an accredited Sodium Lauryl Ether Sulfate 70 factory, we enforce strict quality protocols—every batch undergoes rigorous testing to ensure consistent efficacy and safety standards.
| Packing | Sodium Lauryl Ether Sulfate 70 is packaged in 250 kg drums, 1,100 kg IBC totes, or bulk tankers. |
| Container Loading (20′ FCL) | 20′ FCL container loading of Sodium Lauryl Ether Sulfate 70, securing drums/IBCs with proper dunnage, labeling, and ventilation for safe transport. |
| Shipping | Sodium Lauryl Ether Sulfate 70 ships in sealed drums or IBCs, labeled as a chemical. Transport in dry, ventilated containers away from extreme heat or cold. Typically non-hazardous for transport; however, if corrosivity criteria are met, classify with proper UN number and hazard labeling. Use PPE and spill containment during loading and unloading. |
| Storage | Store Sodium Lauryl Ether Sulfate 70 in a cool, dry, well-ventilated area away from direct sunlight and heat sources. Keep the container tightly closed to prevent moisture absorption and contamination. Avoid freezing and extreme temperatures, which can alter the product. Store separately from strong oxidizers and incompatible materials. |
| Shelf Life | Shelf life is typically 1 year from manufacture when stored sealed, cool, and dry, avoiding extreme temperatures. |
In compounding sulfate-based shampoos, Sodium Lauryl Ether Sulfate 70% (SLES-70) functions as the primary anionic micellar builder, but the manner of its introduction into the aqueous phase dictates whether a factory encounters a 2–4‑hour gel hold-up or a seamless single‑pass blend. Production‑scale mixing vessels equipped with 45° pitched‑blade turbines operating at 80–120 rpm typically receive SLES‑70 pre‑diluted to 25–30% active matter via an in‑line static mixer before the main tank. Direct addition of the 70% paste into a vortex without an eductor routinely forms a viscous, liquid‑crystalline hexagonal‑phase mesophase that stalls further solubilisation; plant logs from a 5,000 L jacketed vessel show temperature must be maintained at 35–40 °C during this stage, because below 30 °C the paste viscosity exceeds 15,000 mPa·s (Brookfield RV, spindle #6, 20 rpm) and hinders pump transfer. The final formulation relies on the electrolyte‑responsive “salt curve”: addition of sodium chloride at 0.8–1.5% w/w shifts the rod‑to‑worm micelle transition, elevating viscosity to a peak of 4,000–8,000 mPa·s before a sharp cliff‑edge drop beyond 2.2% NaCl. Control laboratories verify the peak using a programmable DV‑II+ rheometer following ISO 2555:2018. Compliance is anchored to EU Cosmetics Regulation 1223/2009, where 1,4‑dioxane content—a processing artefact from ethoxylation—is held below 10 ppm as per the industry reference method ISO 10130:2009 (Headspace GC‑MS). Manufacturing hygiene follows ISO 22716:2007 clauses 4.12 (starting materials) and 8.3 (in‑process control). SLES‑70 is formulated at 9–14% as‑supplied weight (equivalent to 6.3–9.8% active) alongside co‑surfactants such as cocamidopropyl betaine and a non‑ionic thickener. The finished product—clear or pearlised shampoo—undergoes accelerated stability at 45 °C for 12 weeks as prescribed in ISO/TR 18811:2018. A documented operational boundary: cationic polymer conditioning agents above 0.15% active must be pre‑mixed with non‑ionic dispersant to avoid coacervate precipitation that manifests as haze within 48 hours of filling.
Cold‑process shower gel manufacturing eliminates the heating cycle entirely, reducing the energy footprint by 40–50% compared to conventional hot‑mix methods, but it places stringent demands on the dissolution kinetics of SLES‑70. Unheated tap water at 12–18 °C requires that the surfactant be fed through a recirculation loop with an in‑line high‑shear disperser (rotor‑stator at 3,000 rpm tip speed) to avoid the formation of gel “fish‑eyes” that would otherwise pass through a 100 μm cartridge filter unchanged. Plant operators monitor the refractive index plateau (1.3600–1.3615 at 25 °C) as an endpoint to confirm complete hydration. The commonly used addition level of SLES‑70 sits at 10–12% as‑supplied weight, paired with sodium lauroyl sarcosinate to suppress the Krafft point below 5 °C, an essential feature when winter transport conditions expose the filled product to sub‑zero temperatures. Industry‑accepted microbial safety follows ISO 11930:2019 challenge test criteria, and the absence of a pearlising agent means any haziness from calcium‑ion‑mediated SLES precipitation must be eliminated by chelators (EDTA 0.1%) or citrate buffers. A critical trustworthiness note: in soft‑water regions with total hardness below 45 ppm CaCO₃, the viscosity response of sodium chloride can be overly sensitive, causing a variation of ±2,000 mPa·s between production batches unless the salt is dispensed from a gravimetric feeder with ±10 g accuracy on a 1,000 kg base. The final body wash is a crystal‑clear, viscous liquid packaged in PE or PET bottles with a disc‑top closure, typically labelled under EU Regulation 1223/2009 Annex III entries for preservatives if applicable.
Liquid hand soap formulated for pump‑dispensed foam—where the foaming engine consists solely of SLES‑70 and an alkanolamide—presents a distinct rheological profile from shampoos, requiring a Newtonian plateau below 50 mPa·s at 25 °C to ensure the pump actuator’s mesh screen (typically 250 μm pore size) produces a uniform bubble size distribution. Production records from a continuous blending line show that SLES‑70 is dosed at 6–8% as‑supplied weight because the pump’s dilution factor of 1:8 (product‑to‑air‑by‑volume) accentuates the flash foam volume measured by the Ross‑Miles method under ASTM D1173-53 (2020 reapproved). The standard prescribes an initial foam height exceeding 120 mm at 0.1% active concentration. A further regulatory layer applies: if the soap carries an antibacterial claim and contains, for example, benzalkonium chloride, the formula becomes a dual‑regulated article under the US FDA Over‑the‑Counter Drug Monograph (21 CFR 333) and requires a New Drug Application for non‑monograph conditions. In such cases, a quarantine holding time of 14 days after filling is enforced for microbial release testing per USP <61> and <62>. The tank‑farm layout must segregate SLES‑70 storage lines from quaternary ammonium compounds to prevent ion‑pair precipitation inside the CIP return system. Terminal packaged units are 250 ml or 500 ml PET foam‑pump bottles, and the manufacturing is audited under the SMETA 4‑pillar framework or equivalent by retail chain buyers.
Manual dishwashing liquids operate at the highest flash‑foam demand among household surfactant products because consumers equate foam persistence with cleaning longevity. SLES‑70 discharge into a 2,000 L atmospheric mix tank is gravimetrically controlled to 12–16% as‑supplied weight, co‑blended with linear alkylbenzene sulfonic acid (neutralised in situ with sodium hydroxide) and an amine oxide. The balance between foam volume and hand mildness is quantified by the Zein protein assay (modified Kligman test, OECD TG 439 skin irritation reference); a Zein number below 150 mg per 100 ml of 10% solution is the line‑in‑the‑sand for the EU Ecolabel (Commission Decision 2017/1214). On‑line specific‑gravity meters (±0.001) verify the active surfactant concentration before the addition of a hydrotrope such as sodium xylene sulfonate to reduce the cloud point below 5 °C. The Clean Air Act (USA) regulates volatile organic compound content, forcing the removal of low‑boiling solvents; SLES‑70-based systems must therefore be formulated without ethanol, using polymeric polycarboxylate dispersants instead. Process engineers document a consistent bottleneck: during the neutralisation exotherm, temperature excursions above 45 °C in the recirculation line degrade SLES‑70’s ether sulphate group, releasing free alcohol detectable by HPLC‑ELSD as a 0.3–0.6% increase in unsulfated matter versus the certificate of analysis. Mandatory in‑process checks follow ISO 4316:1977 (pH measurement) and ASTM D2357-74 (2018) for active matter titration. The final product—a clear, high‑viscosity liquid with a glycerol humectant—fills PE‑HD bottles and carries the INCI declaration under EU Detergent Regulation 648/2004 Annex VII, with a requirement for compliance with biodegradability methods OECD 301B or ISO 7827:2010 achieving >60% mineralisation in 28 days.
Vehicle exterior cleaning concentrates demand foam that remains structurally coherent when sprayed through a 0.8 mm orifice foam cannon at dilution factors as lean as 1:900. SLES‑70 is incorporated at 18–22% as‑supplied weight in bucket‑truck concentrates and adjusted downward to 10–14% in triple‑foam‑wax systems where a cationic surfactant overlay is present. The crucial performance criterion is drainage time measured with a Nessler cylinder and a stopwatch per a modified Ross‑Miles method: an acceptable foam half‑life exceeds 180 seconds under 150 ppm hard water (Ca:Mg 2:1 molar). This specification echoes the cleanliness standard IICRC S300 for professional detailing. To satisfy the VOC limits of CARB (California Air Resources Board) Consumer Products Regulation, the formulation uses exempt‑compound carriers and omits hydrotreated distillates. The blending procedure in 10,000 L vertical domed‑top tanks often encounters phase separation when SLES‑70 is combined with chelating agents like EDTA‑4Na at concentrations above 2% without a sufficient hydrotrope; the corrective action is the prior dissolving of hydrotrope (sodium cumene sulfonate 3–5%) before surfactant charging. Transfer pumps must be progressive‑cavity type to avoid cavitation at the high paste viscosity of the raw SLES‑70, which at 20 °C reaches 10,000–20,000 mPa·s according to the supplier’s certificate of conformance. End‑use commercial car soaps are distributed as 5 L jerrycans or 55‑gallon drums, accompanied by a Safety Data Sheet compliant with GHS Revision 8 and REACH Annex II. Published data on the specific compatibility of SLES‑70 with high‑molecular‑weight anionic polyacrylamide friction reducers in wash‑water recycling systems is limited, so formulators are advised to conduct jar testing before committing to full‑scale batches.
Encapsulation cleaning of synthetic upholstery textiles using a low‑moisture foam shampoo relies on the ability of SLES‑70 to generate a dry, stable foam bolster that carries polymer‑entrapping soils without wetting the underlying fabric backing to a depth exceeding 3 mm. This is a niche but growing segment driven by the IICRC S100 standard for textile floor coverings and its extension to fibre‑covered furniture. The batch sheet specifies SLES‑70 at 5–8% as‑supplied weight, combined with polyvinylpyrrolidone (PVP K‑30) as a soil‑release polymer and isopropyl alcohol as a fast‑breaking solvent; the flash point of the formulated product must remain above 60 °C (closed cup, ASTM D93-20) to avoid classification as a flammable liquid under 49 CFR transport regulations. Blending is performed in explosion‑proof vessels with nitrogen‑purged headspace, and the sequence mandates the pre‑mixing of alcohol with PVP before surfactant introduction to prevent polymer precipitation. A known failure mode on high‑shear dispersion equipment (Silverson L5M rotor‑stator at 5,000 rpm) is the shear‑induced cleavage of the ethylene oxide chain in SLES, which liberates ethylene oxide—a trace amount but sufficient to trigger a photoionisation detector alarm at 0.5 ppm threshold. Therefore, process engineers implement an interlock that limits shear rpm to 3,500 when the batch temperature exceeds 35 °C. The final product is dispensed from aerosol cans using a hydrocarbon propellant (A‑70) or as a ready‑to‑use trigger sprayer; the aerosol version must pass the hot water bath test at 55 °C per UN 31HA1 package performance criteria. Aerosol foam stability is internally evaluated by a foam collapse tower (a 500 ml graduated cylinder at 50% relative humidity), with the acceptance criterion being less than 10% liquid drainage after 5 minutes. Regulatory oversight references the Aerosol Dispensers Directive (75/324/EEC) as amended by 2016/2037, particularly for burst pressure safety margins of a minimum of 20% above the calculated equilibrium pressure at 50 °C.
| Application Context | SLES-70 (as‑supplied wt%) | Viscosity Plateau (mPa·s, 25°C) | Primary Foam Standard Ref. | Acceptable Free Alcohol Threshold (wt%) |
|---|---|---|---|---|
| Hair Shampoo | 9–14 | 4,000–8,000 | Internal (ISO 2555) | <1.2 |
| Body Wash (Cold‑Process) | 10–12 | 2,500–6,000 | Internal (Brookfield RV) | <1.0 |
| Pump Foam Hand Soap | 6–8 | <50 (Newtonian) | ASTM D1173-53 | <0.8 |
| Manual Dishwashing Liquid | 12–16 | 800–3,000 | OECD TG 439 / ASTM D1173 | <1.5 |
| Car Wash Concentrate | 18–22 | 500–1,500 (concentrate) | Modified Ross‑Miles (IICRC S300) | <1.8 |
| Upholstery Foam Shampoo | 5–8 | 100–400 (dilute) | Foam Collapse Tower (proprietary) | <1.0 |
| Segment | Primary Substance Regulation | GMP / BRC Standard | Biodegradability Reference | Test Method for Dioxane / Impurity |
|---|---|---|---|---|
| Hair Shampoo | EU Regulation 1223/2009, US 21 CFR 700 | ISO 22716:2007 | OECD 301D | ISO 10130:2009 |
| Body Wash | EU 1223/2009, Annex III | ISO 22716:2007 | ISO 7827:2010 | Headspace GC‑MS (in‑house) |
| Pump Foam Hand Soap | EU 1223/2009 / FDA OTC Monograph | 21 CFR 211 (US) | OECD 301B | USP <467> |
| Manual Dishwashing | EU Detergent Reg. 648/2004 | BRC Global Standard CP | ISO 7827 | Wickbold Method (ISO 4323) |
| Car Wash Concentrate | REACH Annex II, GHS Rev 8 | ISO 9001:2015 | OECD 301F | Supplier CoA only |
| Upholstery Foam Shampoo | Aerosol Directive 75/324/EEC | UN 31HA1 package cert. | ASTM D5864 | PI detector alarm limit 0.5 ppm |
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An aqueous concentrate containing nominally 70% w/w sodium lauryl ether sulfate (INCI: Sodium Laureth Sulfate, CAS 68891-38-3)—synthesized via sulfation of ethoxylated dodecyl alcohol followed by neutralization—is supplied as a clear, viscous liquid. The product typically carries a mean ethoxylation of 2 moles EO per mole fatty alcohol, yielding the predominant homologue C12H25(OCH2CH2)2OSO3Na. Industrial parlance frequently designates this material SLES-2 EO 70%, distinguishing it from higher-solids pastes and from narrow-range ethoxylates.
In raw form at 25 °C, SLES 70 exhibits a non-Newtonian, shear-thinning flow curve with typical viscosities spanning 5,000–25,000 mPa·s at low shear, dropping sharply under the shear rates encountered in positive-displacement transfer. This pseudoplasticity, governed by worm-like micellar entanglement, imposes specific constraints on diaphragm and progressive cavity pump sizing. Installation of a VFD-controlled pump with a suction-side pressure sensor prevents cavitation when ambient temperatures fall below 15 °C, where gel-phase domains can raise apparent viscosity beyond 50,000 mPa·s. Storage in 316L stainless steel jacketed vessels maintained at 30–35 °C, per supplier bulk handling guidelines, ensures consistent flow without exceeding the product’s thermal stability threshold of 50 °C, above which colour (Klett, <30 on 5% AM solution) begins to drift.
Formulation chemists routinely exploit a hydrotrope-mediated viscosity dip: incorporation of 2–4% sodium xylene sulfonate (SXS) reduces the concentrate’s viscosity below 2,000 mPa·s, enabling direct metering through magnetic-drive gear pumps without heated lines. Published data for this specific configuration in a monodisperse ethoxylate distribution is limited; plant-scale trials typically calibrate pump stroke frequency against a Coriolis mass flow meter to compensate for day-to-day rheological drift.
| Parameter | Typical Range | Reference Method |
|---|---|---|
| Active Matter (M.W. 382) | 69.0–71.0% | ISO 2271 (two-phase titration) |
| Unsulfated Matter | ≤ 2.0% | ISO 894 |
| Sodium Sulfate | ≤ 1.5% | ISO 3262 |
| pH (2% aqueous) | 7.0–9.0 | ASTM D1172 |
| 1,4-Dioxane | ≤ 30 mg/kg | Headspace GC-MS (EPA 8260C) |
| Colour (Klett, 5% AM) | ≤ 25 | Klett-Summerson |
When the manufacturing environment requires AN (ammonium-neutralized) or MEA variants, the 70% sodium form serves as a benchmark for electrolyte tolerance. The divalent cation sensitivity—common to alkyl ether sulfates—dictates that process water hardness exceeding 120 mg/L CaCO₃ precipitates calcium lauryl ether sulfate, resulting in a dull haze that cannot be removed by downstream polishing filtration below 5 µm. Chelation with tetrasodium glutamate diacetate (GLDA) at a stoichiometric ratio of 1.2:1 relative to calcium concentration restores clarity without the nitrogen content of EDTA alternatives.
Comparison with sodium lauryl sulfate (SLS, SLS needles or SLS 30%) reveals the fundamental impact of the polyoxyethylene spacer. SLS denatures globular proteins aggressively; SLES-2 reduces ocular sting scores in Draize assessments by roughly 60–70% compared to SLS at equivalent active surface tension (28–32 mN/m at CMC), according to historical in-vivo data. The shift is attributed to a larger hydrated head group area, reducing monomer penetration into the stratum corneum. In shampoo formulation, the critical micelle concentration drops from 8.2 mM (SLS) to approximately 0.25 mM (SLES-2) in deionized water, allowing efficient micellization at lower surfactant mass.
Measured against narrow-range ethoxylates (NRE), the conventional broad-ethoxamer SLES 70 exhibits a wider gel region upon dilution from concentrate to intermediate water contents. Phase diagram mapping at 25 °C identifies a hexagonal liquid crystalline phase between 35–50% active matter, where viscosity peaks above 1,000 Pa·s. Processing installations therefore inject the 70% concentrate directly into the vortex of a pre-filled batch with >60% free water to bypass this “gel band,” a handling step absent in cold-processable SLES-1 70% systems that exhibit no stiff mesophase at ambient temperature due to a different critical packing parameter.
For structural foam applications in concrete admixtures, the ether sulfate’s 70% active matrix outperforms lower-solids grades (28% aqueous solutions) by eliminating unnecessary water freight and reducing the carbon footprint per kg transported surfactant by 38% (IPCC-derived transport emission factor for road freight). Field data from on-site foam generators operating at 3 bar compressed air pressure indicate that pre-dilution of SLES 70 to 30% active with chilled water (5–10 °C) suppresses pre-generated foam collapse caused by localised heating in the high-shear mixing head.
Formulation scientists must not treat anionic ether sulfates as mutually substitutable in multicomponent systems. SLES 70 interacts with amphoteric co-surfactants—cocamidopropyl betaine (CAPB) constitutes the canonical pairing—to form mixed micelles that maximise viscosity at a CAPB:SLES weight ratio near 1:3.5 on an active basis. The resulting peak viscosity of 8,000–15,000 mPa·s (Brookfield RV, Spindle 6, 20 rpm) in a 12–14% total active wash can be trimmed to 4,000 mPa·s by addition of 0.5% NaCl. Production sites operating continuous blending skids must control salt addition via a weigh cell and in-line static mixer to avoid over-thickening that triggers positive-displacement pump over-pressure trips set at 10 bar.
Partial substitution of SLES 70 with sodium lauroyl sarcosinate at 5% of the total surfactant actives sharpens foam texture without destabilising the maltese-cross micellar structure verified under polarised light microscopy. In alkaline household cleaners (pH 10.5–11.0), the 70% ether sulfate resists hydrolysis significantly longer than the equivalent lauryl sulfate: half-life under pH 11 at 40 °C exceeds 90 days, whereas sodium lauryl sulfate monitors exhibit 15–20% sulfate cleavage within the same period, based on accelerated ageing data monitored by two-phase active titration.
During the cold-fill production of pearlescent shampoos, ethylene glycol distearate crystal habit is sensitive to the ethoxamer distribution. The broad-distribution SLES 70 nucleates smaller, more uniform platelet clusters (5–10 µm) than narrow-range grades, resulting in a brighter pearl but occasionally retarding crystal settling rates in 500 kg holding tanks, risking stratification if batch holdup exceeds 4 hours.
Where formulation requires extreme viscosity suppression for sprayable hand soaps, replacement of 30% of the SLES 70 active with sodium diethylhexyl sulfosuccinate (DOSS) shifts the packing parameter toward reverse micelles, lowering the system’s zero-shear viscosity below 200 mPa·s. However, this combination is incompatible with low-pH preservative systems (pH < 4.5) due to accelerated DOSS ester hydrolysis; citric acid buffer must maintain pH above 5.2.
| Attribute | SLES-2 70% (Broad EO) | SLS 30% | SLES-1 70% | Sodium Methyl 2-Sulfolaurate |
|---|---|---|---|---|
| CMC in water (25 °C) | ~0.25 mM | ~8.2 mM | ~0.18 mM | ~0.04 mM |
| Krafft Point | <0 °C | ~16 °C | <0 °C | <0 °C |
| Gel Phase (25 °C) | Present (35–50% AM) | Present (35–60% AM) | Absent | Absent in typical ranges |
| Ocular Irritation Potential | Moderate-low | High | Moderate-low | Very low |
| Electrolyte Thickening Response | Strong | Strong | Weaker | Weak |
Global regulatory alignment imposes a bifurcation in SLES 70 quality: a high-conversion grade targeting <10 mg/kg 1,4-dioxane under REACH Annex XVII restrictions and the California Proposition 65 listing, versus a technical grade that may reach the 30 mg/kg ceiling acceptable for industrial I&I cleaners. Stripping columns operating under vacuum (50–80 mbar) post-neutralisation remove the bulk of dioxane, but subsequent storage in epoxy-lined drums at ambient temperature can regenerate trace amounts through acid-catalysed back-formation if the pH drifts below 6.5. Therefore, the product must be monitored quarterly using GC-MS per EPA 8260C, with a control limit of 20 mg/kg set at 3σ above process mean for batch release in personal-care supply chains.
Residual sulfate ion, measured as sodium sulfate, directly impacts the freeze-thaw stability of finished shampoos. At sulfate levels above 1.8% in the concentrate, products stored at −5 °C develop needle-like sulfate crystals visible under 10x magnification, which do not redissolve upon warming to 25 °C—a failure criterion per internal cosmetics stability protocol based on ISO 18811:2018. Producers of SLES 70 for this sector therefore control the sulfation-to-neutralisation step with a post-reaction vacuum flash removing residual SO₂, keeping final sodium sulfate content within 0.8–1.2%.
In compliance with the EU Ecolabel for rinse-off products (Commission Decision 2014/893/EU), the aerobic biodegradability of SLES 70 exceeds 90% within 28 days (OECD 301B, modified Sturm test), qualifying it as readily biodegradable. The ethoxylate chain is cleaved under standard activated sludge conditions without formation of stable polyethoxylate intermediates. No persistent, bioaccumulative or toxic (PBT) classification applies under REACH Annex XIII, although the concentrate is classified as Skin Irritant 2 (GHS07) and causes serious eye damage (Category 1, GHS05) in undiluted form, mandating secondary containment and splash protection during decanting.
Automated drum decanting stations in continuous surfactant feeds often incorporate load cells with ±0.1% accuracy and a lance pump interlocked to a conductivity sensor in the drip tray to detect leaks. The material’s specific gravity of 1.05–1.07 g/mL at 40 °C permits a 1000 L IBC to be evacuated within 25 minutes using a 2-inch air-operated double diaphragm pump with a PTFE diaphragm specification, provided the discharge head does not exceed 12 m. Plant safety documentation must cover spill containment with inert absorbents such as vermiculite, noting that aqueous dilution generates abundant foam that interferes with floor scrubber vacuum recovery.