Buyer-facing sourcing candidate for Optical Brightener OB-1, also referenced as Fluorescent Brightener 393 or FBA 393, CAS 1533-45-5. Listed material is a bright yellowish-green crystalline powder for plastics and polyester-related applications, with stated purity of 98.5% minimum and packing in 25 kg drums, boxes, or bags. Overseas buyers should verify CAS, assay method, melting point range, impurity profile, COA consistency, SDS availability, export documentation, and shipment classification before RFQ confirmation.
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.: 1533-45-5Chemical auxiliary / optical brightener for plasticsCandidate for RFQ and document verification
Color masterbatch and whitening additive formulators
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 stated as 25 kg per drum, box, or bag.
Confirm exact inner liner, moisture barrier, drum or carton strength, palletization, and export label format.
Request photos of export packing and pallet loading before shipment.
Confirm whether sample packing is available and whether sample COA matches bulk-lot specification.
For Bangladesh import planning, confirm carton/drum dimensions, gross weight, net weight, and container loading quantity.
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
Whitening additive candidate for plastic compounding where OB-1 / FBA 393 is specified by CAS 1533-45-5
Candidate optical brightener for masterbatch production after compatibility and shade testing
Polyester-related brightening applications where buyer specifications call for high-temperature-resistant optical brightener
Distributor stock item for plastics and chemical auxiliary portfolios serving Bangladesh industrial buyers
Replacement or alternate-source qualification for existing OB-1 supply, subject to lab approval and batch comparison
How we compare
Sourcing options
Sample evaluation before bulk order, with sample COA requested
MOQ purchase around 100 kg as listed, subject to supplier confirmation
Commercial order in 25 kg export packs with buyer-confirmed labeling and palletization
FOB China port or CIF/CFR Bangladesh route to be requested during RFQ
Third-party inspection or pre-shipment sample retention for quality assurance
Custom packing discussion for distributor resale or warehouse handling requirements
Human review
Compliance notes
Request current COA for the offered batch showing CAS number, assay or purity, appearance, melting point, and any declared impurities.
Request SDS in English and confirm whether local-language SDS or label support is available for destination import clearance.
Confirm transport classification with supplier and freight forwarder before booking; do not rely only on marketplace category text.
Verify HS code, product name, CAS number, and invoice description consistency across PI, COA, SDS, packing list, and customs documents.
Ask whether the supplier can provide certificate of origin, commercial invoice, packing list, COA, SDS, and applicable export declaration documents.
Confirm whether the material is subject to any destination-market registration, notification, or chemical inventory requirements before purchase.
No regulatory approval or customs clearance outcome should be assumed from the listing; buyer should verify with local importer, broker, and competent authority.
Check whether the intended plastic application involves food-contact, toy, medical, or regulated consumer goods, as additional compliance documentation may be required.
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.
optical brightener OB-1 supplierfluorescent brightener 393 CAS 1533-45-5FBA 393 optical brightenerOB-1 for plasticsplastic whitening agent supplieroptical brightener supplier for Bangladeshfluorescent whitening agent for masterbatchCAS 1533-45-5 China supplierOB-1 98.5% purityHS code 32042000 optical brightener
Related product options
Build a broader quote package from adjacent options.
Buyers often compare neighboring grades, forms, or route options before sending one consolidated RFQ.
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
Can you confirm the supplied material is Optical Brightener OB-1 / FBA 393 with CAS 1533-45-5 and provide a recent batch COA?
What analytical method is used for the stated 98.5% minimum purity, and can you share the specification limit table?
What are the typical impurity controls, including insoluble matter, ash, moisture, volatile matter, particle size, and color shade consistency?
Can you confirm the melting point range for recent production lots and provide retained-sample data if available?
Is the product suitable for the buyer's resin system, such as PP, PE, PVC, PET, PS, ABS, or polyester fiber applications?
Can you provide SDS, COA, TDS, certificate of origin, packing list, commercial invoice, and product label draft before shipment?
What is the available packing option for export to Bangladesh: 25 kg drum, box, or bag, and what are the pallet dimensions and gross weight?
What is the current lead time for sample, 100 kg MOQ, and larger commercial quantity orders?
Checks before quote
Request current COA for the offered batch showing CAS number, assay or purity, appearance, melting point, and any declared impurities.
Request SDS in English and confirm whether local-language SDS or label support is available for destination import clearance.
Confirm transport classification with supplier and freight forwarder before booking; do not rely only on marketplace category text.
Verify HS code, product name, CAS number, and invoice description consistency across PI, COA, SDS, packing list, and customs documents.
Ask whether the supplier can provide certificate of origin, commercial invoice, packing list, COA, SDS, and applicable export declaration documents.
Confirm whether the material is subject to any destination-market registration, notification, or chemical inventory requirements before purchase.
No regulatory approval or customs clearance outcome should be assumed from the listing; buyer should verify with local importer, broker, and competent authority.
Check whether the intended plastic application involves food-contact, toy, medical, or regulated consumer goods, as additional compliance documentation may be required.
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.
