A label that says only “polymer” or “water thickener” has not named the salt. Sodium Polyacrylate is the sodium salt of polyacrylic acid. The product page lists INCI Sodium Polyacrylate, CAS 9003-04-7, and the repeating unit (C3H3NaO2)n. It arrives as a white to off-white powder. In water it does not behave like a small soluble crystal: it hydrates into a viscous solution or a gel, and the thickness depends on how much you add and what else is in the water.
How this salt differs from polyacrylamide, and why the 5 ppm acrylamide figure does not belong on this COA, is in Polyacrylamide’s 5 ppm Limit Is Not Sodium Polyacrylate.
What the INCI and COA are locking
Write Sodium Polyacrylate and CAS 9003-04-7 on the sample request. Secondary CosIng-style mirrors sometimes print extra CAS lines beside 9003-04-7 for this INCI name. Treat those as a documentation check. The grade on this site is identified by 9003-04-7. If a COA prints a different number, ask whether that number is the polymer you ordered or a related monomer or salt before you accept the drum.
The specification block describes solubility as soluble or dispersible in water, forming a viscous polymer solution or gel depending on concentration. Purity is “high purity,” with the typical specification set to the customer’s requirement. That means the assay, viscosity grade, or residual spec you care about has to be written into the RFQ. A blank “high purity” line is not a finished specification.
Suggested pH on this page is 6.0–8.0 in the aqueous system. Store the powder cool, dry, and well closed, away from moisture and sunlight. A damp bag starts to gel before you weigh it.
What “in skincare” is deciding
Searches for sodium polyacrylate in skincare, what it is, and its function in cosmetics are placement questions. On this page the jobs are rheology modification, water binding, formulation stabilization, and film formation in creams, lotions, gels, and other aqueous personal-care systems. Those are processing and texture roles. They are not a claim that the powder treats skin, and they are not a moisturizing clinical result you can paste onto the raw material.
There is no single use percent on the product page. The guideline is to set the level from the viscosity, texture, polymer grade, and the rest of the chassis, then confirm on the TDS of the lot you buy. A percent copied from a diaper-polymer data sheet, or from a different acrylate thickener, is not this grade’s dose.
Sodium Hyaluronate can share a gel when the brief wants extra water-binding. It is a polysaccharide, specified by its own molecular-weight range and its own COA. Sodium polyacrylate does not replace it on the purchase order, and hyaluronate does not replace this acrylate salt.
The diaper grade is a different specification
Searches for sodium polyacrylate in diapers, and for the crystals, are looking at a superabsorbent use. Public descriptions of superabsorbent sodium polyacrylate often quote very large water uptake, on the order of many times the polymer’s mass. That story is about locking water so it does not release easily.
The cosmetic grade on this page is described as soluble or dispersible, forming a viscous system the formulator can still process. Do not copy a diaper absorbency number onto a skincare COA, and do not brief this powder as the diaper crystal. Ask which grade the lot is, then match appearance, hydration behavior, and the COA to a leave-on or rinse-off cosmetic chassis.
How to disperse it, and what salt does
Sprinkle the powder into the water phase with enough agitation to keep it from clumping. Pre-disperse before full hydration. Let it hydrate before you judge the final thickness. Judging viscosity on a dry lump, or immediately after the powder hits the water, misses the grade.
The same specification says electrolytes, surfactants, actives, and other polymers can change performance. A search for sodium polyacrylate and salt is that warning. An acrylate thickener built in plain water can thin once ions are in. If the formula contains a high level of salts, check viscosity after those salts are added, not only in a salt-free trial. Then run the physical-stability check the guideline asks for, including accelerated conditions if that is your protocol. There is still no universal percent: set it from the rheology you need and from the TDS.
How to read a safety line
Cosmetic-ingredient pages sometimes restate a CIR-style qualification that sodium polyacrylate is acceptable in cosmetics when the formula is made to avoid irritation. That sentence is a framing of finished-product practice. It does not supply a use percent for this lot, and it does not transfer polyacrylamide’s residual-acrylamide limit onto this salt. Irritation, if it shows up, is judged on the finished product and on the grade’s own documents. The monomer question that belongs to polyacrylamide is in the companion note.
What not to substitute silently
Four mix-ups show up on the same RFQ thread.
A diaper or hygiene superabsorbent, even with the same common name, is not this cosmetic hydration profile until the COA and the TDS say so.
Polyacrylamide is a different monomer and a different residual-monomer spec. Potassium polyacrylate is the potassium salt. Carbomer is another acrylic thickener. None of those names fills an order for Sodium Polyacrylate, CAS 9003-04-7. This site does not list product pages for those three; do not invent URLs for them.
Sodium hyaluronate remains a second SKU when both water-binding stories are in the chassis.
What to send before the first sample ships
Put these lines in the message to the supplier:
- INCI Sodium Polyacrylate; CAS 9003-04-7
- Cosmetic grade, not a diaper superabsorbent specification
- Appearance: white to off-white powder; the viscosity or hydration note you will accept
- pH window 6.0–8.0 for the aqueous system, and confirmation you will disperse then hydrate
- Whether the pilot water phase contains electrolytes, and that the sample must still thicken there
- Bench-sample pack size, plus COA, SDS, and TDS with the shipment
Batch documents and a sample are available from the product page. Match the sample to the salted or unsalted base you will actually make, then scale. A clear CAS and grade line usually returns documents and a quote. A vague “polymer” or “SAP crystals” line usually returns clarifying questions first.
