TBPA vs CAS 126-73-8: Procurement Specs & Identity Check
Analyzing Procurement Specs: TBPA Identity Versus CAS 126-73-8 Discrepancies
Procurement errors often stem from acronym confusion between Tetrabromophthalic Anhydride (TBPA) and Tributyl Phosphate (TBP). While both are industrial chemicals used in polymer modification and flame retardancy, they possess distinct chemical identities. TBPA corresponds to CAS Registry Number 632-79-1, whereas CAS 126-73-8 identifies Tributyl Phosphate. Misclassifying these substances during sourcing leads to significant formulation failures, as their molecular structures and functional groups differ entirely.
Data extracted from standard chemical registries confirms that CAS 126-73-8 corresponds to a phosphate ester with the molecular formula C12H27O4P and a molecular weight of 266.32 g/mol. In contrast, true TBPA is a brominated phthalic anhydride derivative. Procurement teams must verify the CAS RN on every Certificate of Analysis (COA) before releasing payments. Relying solely on the acronym "TBPA" without cross-referencing the CAS number invites risk, as some legacy databases or non-specialized suppliers may incorrectly map acronyms to available stock rather than technical specifications.
Understanding this discrepancy is critical for supply chain integrity. If a purchase order specifies TBPA for reactive flame retardant applications but the delivered material matches the physical properties of CAS 126-73-8, the resulting polymer blend will lack the required bromine content for effective fire suppression. Technical buyers must insist on GC-MS verification to distinguish between the aromatic brominated structure of TBPA and the aliphatic phosphate structure of CAS 126-73-8.
Essential Quality Parameters for Tetrabromophthalic Anhydride Sourcing
When sourcing high-purity Tetrabromophthalic Anhydride reactive flame retardant, specifications must go beyond basic identity confirmation. Industrial purity standards for CAS 632-79-1 typically require assay values exceeding 98.0%, with strict limits on residual solvents and unreacted intermediates. The presence of moisture is particularly critical, as anhydrides are susceptible to hydrolysis, which converts the material into the corresponding acid and compromises reactivity during polymer modification.
Key quality parameters include melting point range, bromine content, and acid value. A deviation in melting point often indicates the presence of isomers or incomplete bromination. For NINGBO INNO PHARMCHEM CO.,LTD., quality assurance protocols prioritize GC-MS profiling to detect trace impurities that could affect downstream synthesis. Buyers should request COAs that explicitly list these parameters rather than generic pass/fail statements.
The following table contrasts the critical physical and chemical specifications of TBPA against the commonly confused CAS 126-73-8 substance to aid in verification:
| Parameter | TBPA (CAS 632-79-1) | CAS 126-73-8 (Tributyl Phosphate) |
|---|---|---|
| Molecular Formula | C8H2Br4O3 | C12H27O4P |
| Molecular Weight | ~479.9 g/mol | 266.32 g/mol |
| Physical State | Solid (Crystalline Powder) | Liquid (Colorless Oil) |
| Primary Function | Reactive Flame Retardant Intermediate | Plasticizer / Solvent / Defoamer |
| Key Element | Bromine (Br) | Phosphorus (P) |
| Solubility | Low in Water, Soluble in Alkali | Low in Water, Soluble in Organics |
This data highlights the impossibility of substituting one for the other. The solid state of TBPA versus the liquid state of CAS 126-73-8 is an immediate visual QC check. Furthermore, the bromine content in TBPA is the active mechanism for flame retardancy in many polymer systems, whereas CAS 126-73-8 relies on phosphorus. Substitution alters the fire safety rating of the final product.
Regulatory Compliance Differences Between TBPA and CAS 126-73-8 Substances
Compliance documentation varies significantly between brominated anhydrides and phosphate esters. Safety Data Sheets (SDS) for CAS 632-79-1 will highlight hazards related to brominated organic compounds, including potential irritation and environmental persistence concerns specific to halogenated species. Conversely, SDS for CAS 126-73-8 focuses on phosphate ester handling, aspiration hazards, and aquatic toxicity profiles distinct from brominated aromatics.
Procurement specialists must ensure that the regulatory documentation matches the chemical identity received. Discrepancies in hazard classifications (e.g., GHS pictograms) often signal a mislabeled shipment. For instance, transport classifications for solid anhydrides differ from liquid phosphate esters regarding packing groups and segregation requirements. Accurate classification ensures that logistics providers handle the material according to its specific chemical risks.
Quality specs such as heavy metal limits and ash content also differ based on the intended application. TBPA used in polymer modification requires low metal content to prevent catalyst poisoning in downstream reactions. Documentation should reflect ICP-MS data for metals like iron, copper, and lead. Relying on generic compliance certificates without chemical-specific data increases the risk of processing issues.
Supply Chain Risk Mitigation When Verifying CAS RN 126-73-8 Documentation
Supply chain risks escalate when documentation references CAS 126-73-8 for orders intended for TBPA. This often occurs due to database errors or supplier inventory substitutions without prior notification. Mitigation strategies involve multi-point verification starting at the inquiry stage. Buyers should explicitly state "CAS 632-79-1" in all purchase orders and require confirmation of this specific RN in the supplier's acknowledgment.
During inbound logistics, random sampling and third-party testing are essential. If a shipment arrives labeled as TBPA but exhibits the physical characteristics of a liquid or possesses a molecular weight near 266 g/mol, it must be quarantined immediately. For complex synthesis scenarios, understanding potential impurities is vital. Teams should review resources regarding Tetrabromophthalic Anhydride troubleshooting tri-n-butyl phosphate in TBPA synthesis to understand how cross-contamination might occur during manufacturing or storage.
Documentation audits should focus on the consistency of batch numbers across the COA, SDS, and shipping manifest. Inconsistencies here often point to blended lots or mislabeled containers. Maintaining a approved vendor list that specializes in brominated intermediates reduces the likelihood of receiving phosphate esters instead of anhydrides.
Vendor Verification Steps to Prevent CAS Misclassification in Procurement
Preventing CAS misclassification requires rigorous vendor vetting. Procurement teams should audit potential suppliers for their technical capability to manufacture or distribute CAS 632-79-1 specifically. Questions regarding their synthesis capabilities, such as their bromination processes, can reveal whether they understand the chemistry. For deeper technical insight into production standards, refer to the Tetrabromophthalic Anhydride synthesis route bromination catalyst process guide.
Verification steps include requesting sample batches for internal QC testing before committing to bulk contracts. Evaluate the supplier's responsiveness to technical queries regarding purity profiles and impurity logs. A verified manufacturer like NINGBO INNO PHARMCHEM CO.,LTD. maintains strict control over CAS identity to ensure product consistency. Avoid vendors who cannot provide detailed GC-MS chromatograms or who hesitate to confirm the CAS RN in writing.
Finally, implement a dual-signature approval process for chemical intake where both procurement and quality assurance verify the CAS number against the purchase order. This administrative control acts as a final barrier against identity errors. By enforcing these technical and administrative checks, organizations safeguard their production lines from the severe consequences of chemical misidentification.
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