Hydroxyethyl cellulose (HEC) selection requires more than a product name or an assay percentage. A buyer needs a defined grade and a viscosity specification with its measurement conditions. This guide separates an existing historical COA from the information still needed for a cosmetic formulation trial.
Start with the viscosity test, not the biggest number
Ask for the grade code, acceptance range, units, solution concentration and its basis, measurement temperature, instrument, spindle and speed. Also request the solution preparation and hydration procedure. Results taken under different conditions cannot be assumed to describe equivalent grades.
Ashland’s Natrosol technical literature illustrates that HEC grades are specified with concentration and viscosity information. That manufacturer reference provides context only; it does not establish equivalence or supply specifications for BIOF material.
HEC reference COA: what the existing file actually reports
Batch ES-240715 was manufactured on July 15, 2024, analysed on July 21, 2024, and carries an expiry date of July 14, 2026. Its stated validity has ended. The original PDF remains available for document review; request current-lot documentation before approving a purchase.
The table below is a selected transcription of that original file, not a new certificate, a complete specification or an endorsement of the historical test methods.
| Field | Specification in reference PDF | Recorded result |
|---|---|---|
| Product / CAS | Hydroxyethyl Cellulose / 9004-62-0 | Identified in document header |
| Appearance | White powder | Conforms |
| Loss on drying | ≤5% | 2.6% |
| Ash content | ≤5% | 2.1% |
| Particle size | 95% pass 80 mesh | Conforms |
| pH | 5.0–8.0 | Conforms; test preparation not stated |
| Viscosity grade and test conditions | Not stated in this PDF | Request separately |
Download historical reference COA (PDF) Request current grade data and batch COA
Why this COA alone cannot choose your grade
The file does not state a viscosity value, grade code or rheological test method. Its assay entry does not fill that gap. Nor does a matching CAS number prove that two HEC grades will hydrate or perform identically in a formulation.
When comparing offers, request a grade-specific TDS and a current COA. Confirm which document controls viscosity release and whether that result will appear on the certificate supplied with your order. Ask for any missing method details rather than assigning a viscosity grade to this historical batch.
Plan hydration and formula evaluation
Obtain the supplier’s dispersing and hydration instructions for the selected grade. Clarify whether surface treatment affects handling, what order of addition is recommended, and what preparation conditions are used for viscosity testing. Avoid using a universal mixing time, temperature or use level without grade-specific support.
Evaluate the complete formulation for hydration completeness, lumps, clarity where relevant, viscosity development, stability and compatibility with the other ingredients and packaging. Define the appearance and flow you need in the finished product before selecting the trial grade.
Information to include in your enquiry
- Product type: gel, serum, cream, cleanser or another format.
- Target viscosity together with your test method, or the texture and flow you are trying to achieve.
- Preferred grade, preparation constraints and relevant formulation components.
- Trial quantity, delivery destination and required document list.
The original PDF uses historical company contact details. For present enquiries, use the current BIOF contact page. ESUREY, a subsidiary of BIOF, handles product documents, inquiries and payments.
HEC product page · Document centre · Request viscosity grade and current documents
Post time: Nov-02-2026
