To source TMDSO in bulk, compare suppliers against one agreed specification, connect sample approval to the material you will order, and confirm packaging, documents and quotation scope before releasing the purchase order. A passing sample and an attractive price are useful starting points; neither completes the purchasing decision.
This checklist covers 1,1,3,3-tetramethyldisiloxane, CAS 3277-26-7. Use it as a working sheet for supplier discussions. For ETOPDA’s current published specification, see the TMDSO product page.
1. Build one supplier comparison sheet
Record each supplier’s answer and the supporting document side by side. Mark an unanswered item as pending rather than treating a verbal assurance as confirmed evidence.
| Compare | Ask for | Resolve before approval |
|---|---|---|
| Product identity and seller | Full chemical name, CAS number and the entity issuing the quotation and invoice | Any difference between the seller, product supplier and exporter names |
| Specification | Agreed limits for purity, Si-H content, chloride, residual acidity and any application-specific requirements | Missing units, reporting basis, methods or specification revisions |
| Batch evidence | Recent lot-specific COAs, with measured results identified separately from limits | A specification sheet presented as evidence of an actual batch result |
| Sample link | Sample lot ID, evaluation record and how the proposed order relates to the approved sample | Unexplained changes in grade, specification or source |
| Packaging and shipment | Package type, net weight, package count, destination and document responsibilities | Unconfirmed package options or a route that has not been checked |
| Commercial scope | Quantity, currency, price basis, delivery term and named place, validity and payment terms | Different inclusions that make two prices appear comparable when they are not |
A specification limit defines an acceptance requirement. A batch result states what was measured for an identified lot. Neither should be labelled a typical value unless it is explicitly provided on that basis. For the detailed parameter review, use the TMDSO COA guide and Si-H content guide; this worksheet focuses on the purchasing decision.
2. Connect sample approval to the first bulk order
Before testing, record the sample lot, agreed specification, evaluation conditions and acceptance criteria. Have the responsible technical reviewer document the outcome and any conditions attached to approval.
- Ask whether the first order will come from the sample lot or a different lot.
- If the lot differs, review the proposed lot’s COA against the agreed specification and your qualification procedure.
- Record which changes require review before dispatch, such as a different grade, source, specification or package.
- Identify who may release the first commercial order and what evidence they need.
A recent COA can support supplier evaluation, but it does not replace the COA for the lot actually supplied. For reaction and process evaluation, refer to the TMDSO scale-up guide.
3. Confirm the actual package and transport plan
Use the product page’s packaging information as a reference, then obtain written confirmation for the actual order: container type, net weight per package, package count and any receiving-site constraints. Do not assume an alternative package is available because another supplier offers it.
Provide the destination and intended transport mode early. Ask the supplier and logistics provider to review the current SDS, applicable dangerous-goods requirements, package suitability and route acceptance. A sample shipment does not establish that the same arrangements are suitable for bulk transport. Confirm the actual handling and storage requirements from the current SDS and your site’s procedures.
4. Check documents by purpose and timing
Agree which documents are required, who provides them and when they will be available. The list depends on the order and destination; it is not a promise that every document is available for every shipment.
| Document | Buyer check | Timing to agree |
|---|---|---|
| Purchasing specification and TDS | Correct product, revision, limits and units; distinguish descriptive technical data from agreed acceptance limits | Before technical approval and quotation acceptance |
| COA | Identified lot, relevant methods or reporting basis, specification limits and actual results clearly distinguished | Recent examples during qualification; supplied-lot evidence at the agreed release point |
| SDS | Correct product and revision; information suitable for review by the receiving and logistics teams | Before sample handling and transport planning |
| Packaging and shipment documents | Consistent product identity, quantities and packages; required transport and import information | Requirements before ordering; final documents at the agreed shipment stage |
| Quotation and order confirmation | Specification reference, quantity, package, price basis, named delivery place and responsibilities | Before purchase-order release |
5. Compare the quoted scope, not only the unit price
Put offers on the same quantity and net-weight basis, then compare the same delivery term and named place. Identify whether freight, insurance, dangerous-goods handling, documentation and destination charges are included or excluded. Ask your logistics or import team to confirm any remaining costs.
Keep the quotation date, validity and offered dispatch window in the comparison sheet. Record the distinction between planned dispatch and expected arrival. An order-specific quotation should establish availability and timing; a website description should not be treated as a stock or delivery commitment.
6. Set a purchase-order release and receipt checkpoint
Before releasing the order, confirm that the technical approval, specification revision, package, quantity, document requirements and commercial terms all refer to the same purchase. List unresolved items with an owner and a decision date.
At receipt, reconcile the delivery and lot documentation with the purchase order, package labels and received quantities. Follow your site’s procedures for package inspection, acceptance and any testing. If the received lot or documentation differs from the approved basis, resolve the discrepancy before releasing the material for use.
7. Send an enquiry that can produce a useful quotation
Use the following outline in your enquiry. If a detail is undecided, say so rather than guessing.
- Product: TMDSO, CAS 3277-26-7.
- Request: COA, Sample, Quote, or a combination.
- Specification: required limits and any application-specific acceptance criteria.
- Quantity: first-order quantity and sample requirement, if applicable.
- Destination: country and receiving location or port; preferred delivery term, if known.
- Packaging: required type or receiving constraints, if any.
- Documents and timing: required documents, evaluation schedule and requested delivery window for feasibility review.
Bulk purchasing questions
Must the first bulk order be from the same lot as the sample?
That depends on your qualification requirements and the order agreement. Record the sample lot and proposed supply lot. If they differ, review the supplied-lot evidence and any additional evaluation your technical team requires before approval.
How should I compare offers with different package sizes?
Compare the same net quantity, then include package-related handling, transport and receiving costs in the review. A lower product price may not mean a lower total cost if the package does not fit your receiving or operating requirements.
Does a dispatch date confirm the delivery date?
No. Ask which date the quotation refers to, what transport arrangements have been checked and which conditions remain open. Confirm the order’s shipment and delivery expectations in writing.
Review product details or start an enquiry
Review the TMDSO product specification and buyer checklist, then contact ETOPDA about a COA, sample or quotation. In your message, write TMDSO bulk enquiry and include the request type and order information above. This gives ETOPDA a clear basis to review product fit, documentation and the proposed supply requirements.