Overview
MESIL® is the East Materials specialty fumed silica line, engineered for applications where standard fumed silica (HJSIL family) does not meet the tighter purity, particle size distribution, or surface chemistry specifications required. Three application categories drive specialty-grade demand:
- Premium cosmetic and personal-care — controlled heavy-metal limits (Pb ≤0.5 ppm, As ≤0.5 ppm) and microbial bioburden for face foundation, BB cream, sunscreen, deodorant, leave-on products
- Pharmaceutical-adjacent formulations — USP/NF compliance pathway support or controlled extractables for pre-pharmaceutical or contract-manufactured tablet flow modification
- High-purity industrial (semiconductor polishing slurry, LED encapsulant filler, optical adhesive) — applications where parts-per-million trace contamination affects yield
MESIL® is functionally comparable to Evonik Aerosil Cosmetic / Aerosil Premium, Cabot Cab-O-Sil Premium, and Shin-Etsu KE series at a 30–40% landed cost discount. CAS 112945-52-5, REACH-registered synthetic amorphous silica, ISO 9001 / ISO 14001 manufactured.
For standard industrial fumed silica (silicone sealant, paint rheology, anti-caking), use the HJSIL® Fumed Silica Hub instead — specialty premium is justified only for the categories above. For pharmacopeia-grade pharmaceutical-excipient silica or food/cosmetic-grade silica with regulatory compliance, see HPSIL® Healthcare Silica.
Typical Specifications
| Property | Specialty fumed silica grade (typical) |
|---|---|
| BET surface area | 170–200 m²/g |
| Carbon content | 0.8–1.4% (DMDS-equivalent treatment) |
| pH (4% slurry) | 3.7–4.7 |
| Tapped density | 60 ± 15 g/L |
| Loss on ignition (1000°C) | <1.5% |
| Particle size distribution | Narrower than standard hydrophobic fumed silica |
| Heavy metals (Pb / As / Cd / Hg) | ≤0.5 ppm each |
| Microbial bioburden | <100 CFU/g (cosmetic-grade) |
| Carbon residue | <0.05% |
Specialty-grade fumed silica sits closer to HMDS-treated specialty chemistry on the BET-vs-surface-chemistry spectrum, with tighter purity controls than standard DMDS-treated hydrophobic grades.
Application Suitability
Cosmetic and personal-care formulations: Face foundation, BB cream, sunscreen, deodorant, leave-on cosmetic products. Tight heavy-metal limits (Pb ≤0.5 ppm, well below EU 1223/2009 Annex IV limits) and microbial bioburden meet premium cosmetic brand requirements. Loading 1–3% in finished product.
Pharmaceutical-adjacent excipient: Oral solid dosage (tablet) flow modification for pre-pharmaceutical or contract-manufactured products. For full USP/NF pharmacopeia compliance, use the HPSIL® pharmaceutical-grade silica line — MESIL is for adjacent applications.
High-purity industrial — semiconductor / electronics / optical: Polishing slurries, electronic encapsulant fillers, optical adhesives — applications where ppm-level trace contamination affects product yield. Loading 5–25% depending on application.
Premium silicone sealants for specialty markets: High-clarity silicone sealants (architectural glazing, medical-device sealants, semiconductor packaging), where the slight yellow tint from carbon contamination of standard hydrophobic fumed silica at high loading is unacceptable. Specialty MESIL grade with lower carbon contamination maintains clarity at 8–12 phr loading.
Specialty vs Standard — Selection Guide
| Use case | First choice |
|---|---|
| Standard industrial silicone sealant | HJSIL R974 (cost-optimised) |
| Standard cosmetic foundation | HJSIL R110 (HMDS-treated, cosmetic-eligible) |
| Premium cosmetic foundation (high-clarity required) | MESIL® specialty grade |
| Pharmaceutical excipient (USP / NF compliant) | HPSIL® pharmaceutical-grade (not MESIL) |
| Premium silicone sealant (clear / medical) | MESIL® specialty grade |
| Semiconductor polishing slurry | MESIL® specialty grade |
| LED encapsulant filler / optical adhesive | MESIL® specialty grade |
| Standard food anti-caking | HPSIL® food-grade (not MESIL) |
General rule: HJSIL for industrial chemistry; HPSIL for healthcare-regulated applications; MESIL® for the specialty middle ground where neither perfectly fits — premium cosmetic, high-purity industrial, optical / electronic.
Procurement and Lead Time
MOQ: 1 pallet (1.0 t) commercial supply. Lead time: 5–6 weeks FOB Shanghai (additional purity-testing extends lead time vs HJSIL standard grades). Container shipments: Can be mixed with other East Materials silica grades. Documentation per batch: Heavy metals CoA (Pb / As / Cd / Hg, each ≤0.5 ppm), microbial bioburden test report, particle size distribution, BET, carbon content. REACH registration documentation on request.
FAQ
What's the difference between MESIL® specialty fumed silica and standard hydrophobic fumed silica (HJSIL R974)?
Both are hydrophobic synthetic amorphous SiO₂. MESIL® specialty has tighter heavy-metal limits (≤0.5 ppm vs ≤1 ppm for standard hydrophobic), narrower particle-size distribution, and lower carbon contamination. Cost premium 20–30% over HJSIL R974. Use for specialty applications where the additional purity matters (premium cosmetic, optical, semiconductor).
Is MESIL® specialty fumed silica USP/NF compliant?
USP/NF pharmacopeia pathway is best served by the HPSIL® pharmaceutical-grade silica. MESIL® is for cosmetic and high-purity industrial — USP/NF pharmacopeia compliance requires the specifically-engineered HPSIL pharmaceutical line.
What's the cost differential vs Evonik Aerosil Cosmetic / Aerosil Premium?
30–40% landed cost discount vs Evonik specialty/cosmetic grades. Independent third-party testing has confirmed equivalence on BET surface area, particle size distribution, carbon content, and heavy-metals limits within typical batch variation either supplier accepts.
What's the typical lead time and MOQ?
MOQ 1 pallet (1.0 t) for commercial supply. Lead time 5–6 weeks FOB Shanghai (vs 4 weeks for HJSIL standard grades — the additional purity testing and tighter QA windows extend production). Container-load shipments available combining MESIL with other East Materials silica grades.
Related & Sister Sites
- HJSIL® Fumed Silica — standard industrial fumed silica (silicone sealant, paint rheology, anti-caking).
- HPSIL® Healthcare Silica — pharmaceutical, dental, food, cosmetic regulated applications.
- HMMAT® Matting Agents — coating-specific applications.
- For silane couplers and reactive surface-treatment chemistries adjacent to specialty fumed silica, see chemzip.com/products/silane-couplers/. For coatings combining specialty silica with flame retardants and TiO₂, see coatingsink.com.
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