Optical Brightener OB-1, CAS 1533-45-5, Fluorescent Whitening Agent for Plastics and Fibers
Sourcing candidate for Optical Brightener OB-1, CAS 1533-45-5, offered as a yellow-green crystalline powder for plastics, polyester fiber, coatings, inks, and related polymer applications. Buyers should verify CAS identity, grade, assay method, melting range, particle size, fluorescence shade, impurity profile, COA consistency, export documentation, and transport classification before RFQ or sampling.
Quick buying facts
Identify the grade, package, and import market before comparing suppliers.
Use this page to check the product identity, common specification points, document scope, package notes, and destination-market questions before sending a China sourcing request.
CAS No.: 1533-45-5Fluorescent whitening agent / optical brightener for polymer and fiber applicationsCandidate for RFQ and specification verification
Reported purity: ≥99.5% or 99.9%; confirm assay basis and test method
Melting point: 357-360°C; confirm batch COA range
Fineness: through 100 mesh minimum; confirm particle size distribution if dispersion is critical
Fluorescence shade: bright blue fluorescence, similar to standard sample; request retained standard comparison
Reported UV absorption wavelength: 374 nm and 434 nm; confirm method and solvent conditions
Application areas listed: PVC, PE, PP, PS, ABS, SAN, PA, PMMA, polyester fiber, coatings, paint, and printing ink
Who uses this page
Target buyers
Plastic additive distributors
PVC compounders and masterbatch producers
Polyolefin and engineering plastic processors
Polyester fiber and textile auxiliary buyers
Coating, paint, and printing ink formulators
Chemical importers seeking China-origin optical brightener supply
Procurement teams requiring CAS-level specification checks before qualification
Before matching
Documents to check
CAS number, grade, assay, and impurity profile
SDS, COA, TDS, HS code, and transport classification
Destination-market import documents before supplier matching
Package and route
Packing notes
Standard packing reported as 25 kg package; confirm drum, carton, bag, liner, and pallet configuration.
Listed package size: 50 cm x 50 cm x 45 cm with 25 kg gross weight; verify actual export packing before order.
Ask whether moisture-proof inner bags, pallet wrapping, and container loading photos are available.
Reported loading: 9 tons; confirm per 20 ft or 40 ft container and whether pallets are included.
Request sample availability, sample packing, courier restrictions, and sample COA before bulk RFQ.
Applications and sourcing options
Check whether this product fits the buyer's actual application.
Clear application, grade, package, and document notes help separate real sourcing demand from a vague price check.
Use context
Common applications
Optical brightening additive qualification for PVC, PE, PP, PS, ABS, SAN, PA, PMMA, and acrylic resin systems
Fluorescent whitening candidate for polyester fiber and selected textile-related applications
Brightening additive evaluation for paint, coating, and printing ink formulations
Distributor stock item for polymer additive portfolios
Supplier comparison against approved OB-1 standard samples
How we compare
Sourcing options
Request a small representative sample with matching COA before trial production.
Qualify at least two lots to confirm shade consistency and dispersion performance.
Compare supplier assay, melting point, particle size, and fluorescence shade against internal specifications.
Use third-party lab testing for CAS identity, purity, and restricted substance screening where end market requires it.
Negotiate packing, palletization, Incoterms, lead time, and document package before issuing purchase order.
Consider alternate optical brighteners only after confirming polymer compatibility, shade target, and regulatory documentation needs.
Human review
Compliance notes
Confirm SDS, COA, TDS, commercial invoice, packing list, and certificate of origin availability for export shipment.
Verify HS code 3204200000 with local customs broker; final classification depends on destination rules and product composition.
Request dangerous goods classification or non-DG statement based on current SDS and transport mode; do not rely only on marketplace listing.
Confirm REACH, RoHS, SVHC, TSCA, food-contact, textile, or toy-related declarations only if required for the buyer’s end market; supplier documents should be reviewed by the importer.
Check impurity profile, residual solvents, heavy metals, and restricted substances if used in regulated plastics, coatings, textiles, or consumer goods.
Confirm whether the product is single substance OB-1 or a formulated brightener blend, especially if concentration, carrier, or dispersion form is offered.
Importer remains responsible for destination-market compliance, labeling, documentation review, and any end-use restrictions.
Buyer search paths
Related sourcing terms
These terms support long-tail discovery while keeping the page focused on useful product and China export buying context.
Share target market, quantity, packaging scope, artwork status, delivery destination, and required documents so CHN Chemicals can prepare a cleaner supplier comparison.
Questions to confirm
Please confirm CAS 1533-45-5 identity and provide latest COA, SDS, and TDS for the offered OB-1 grade.
Is the quoted purity 99.5% or 99.9%, and which analytical method is used for assay?
Can you provide impurity limits, residual solvent data, heavy metal data, and batch-to-batch COA examples?
What is the standard particle size or mesh passing rate, and can particle size be customized?
What is the fluorescence shade standard, and can you provide a comparison against the buyer’s approved sample?
Is this product powder only, or can you supply masterbatch, dispersion, or customized concentration forms?
What is the minimum order quantity, sample quantity, sample lead time, and bulk production lead time?
What export packing is used for 25 kg units, and can you provide palletization and container loading details?
Checks before quote
Confirm SDS, COA, TDS, commercial invoice, packing list, and certificate of origin availability for export shipment.
Verify HS code 3204200000 with local customs broker; final classification depends on destination rules and product composition.
Request dangerous goods classification or non-DG statement based on current SDS and transport mode; do not rely only on marketplace listing.
Confirm REACH, RoHS, SVHC, TSCA, food-contact, textile, or toy-related declarations only if required for the buyer’s end market; supplier documents should be reviewed by the importer.
Check impurity profile, residual solvents, heavy metals, and restricted substances if used in regulated plastics, coatings, textiles, or consumer goods.
Confirm whether the product is single substance OB-1 or a formulated brightener blend, especially if concentration, carrier, or dispersion form is offered.
Importer remains responsible for destination-market compliance, labeling, documentation review, and any end-use restrictions.
Next step
Send the product page with your target quantity and market. A sourcing manager can then confirm sample options, supplier fit, packaging details, and open document gaps.
