ZLEY® BRC-WS: A 4-Butylresorcinol Blend for Brightening Formulas
ZLEY® BRC-WS is a formulated ingredient blend containing 4-Butylresorcinol (CAS 18979-61-8). Check identity against the current ZLEY® BRC-WS technical data sheet and PubChem.
What is in the blend?
The published ZLEY® technical sheet lists water, propanediol, hydroxypropyl cyclodextrin, 4-Butylresorcinol and sodium bisulfite. It specifies 12.5% ± 1.0% 4-Butylresorcinol in the supplied blend. This is a different material from neat 4-Butylresorcinol powder: a percentage of BRC-WS added to a formula is not the same percentage of the active molecule.
| Buyer check | Why it matters |
|---|---|
| Active content | Calculate the active contribution from the actual batch assay. |
| Carrier composition | Check compatibility with the complete formula and its labeling requirements. |
| Appearance and pH | Compare the delivered batch with the current COA and TDS. |
| Finished-product stability | Test color, clarity, packaging and performance under relevant storage conditions. |
Use level is not a universal safety limit
The published TDS suggests a 1–6% addition level for the blend. It is a supplier formulation suggestion, not a universal regulatory maximum or a guarantee of finished-product safety. The older table of product-type “maximum safe concentrations” lacked a verifiable source and has been removed. Choose a level through market-specific regulatory review, exposure assessment and testing of the finished formula.
The supplier safety data sheet flags irritation hazards when handling the concentrated raw material. This does not establish the safety or irritation profile of every diluted finished product; both raw-material handling and finished-product use need their own assessment. Likewise, claims of improved penetration, sustained release or superior clinical performance need evidence specific to the grade and finished formula.
Compare grades and request documents
See the ZLEY® BRC-WS product page for the marketed blend. If you are comparing it with the neat powder, read our 4-Butylresorcinol formulation guide and request current TDS, SDS and batch COA for both grades. Send your format and target market to [email protected] so the discussion starts with the relevant specifications.