Procurement Checklist for Chemical and Pharma Buyers: 6 Checks Before You Send a PO

Removing a bad batch from a pharma line is not like removing a typo from a brochure. You do not reprint after the fact. Once a chemical is released, mixed into a coating, or used as a cleaning agent, an unnoticed error turns into a deviation, a write-off, or a recall.

I have spent most of the last eight years on the procurement side of specialty chemical formulating. I manage a purchasing budget in the seven-figure range, negotiate annual supply agreements, and track cost per good batch rather than unit price. What I have learned is that almost every expensive correction could have been stopped by information available before the order was placed.

This checklist is the version I use when onboarding a new supplier or renewing a high-risk material. It is not a full GMP audit; it is a prevention layer before the purchase order goes out. There are six checks below. Check 4 is the one that surprises experienced buyers most.

1. Search by active substance, not by brand name

In crop-protection purchasing, the most important question is not whether a product is registered. It is: what products have paraquat in them? Paraquat is easy to miss because trade names do not always contain the word paraquat.

According to the U.S. EPA, paraquat dichloride is a restricted-use herbicide; only certified applicators may buy or handle it in the United States. According to European Commission Decision 2007/360/EC, paraquat is no longer approved in the EU. Registered product names include Gramoxone, Parazone, and several generic paraquat dichloride concentrates. The active ingredient line should be read, not skimmed.

What many procurement people miss is that a product can be sold under a separate adjuvant brand while still containing paraquat. If the label lists “paraquat dichloride 29.1%” or “42%,” stop treating it like a standard input order. A quick regulatory check in the destination country is cheaper than a rejected container.

2. Ask for the sodium hydroxide production route

Sodium hydroxide is a classic example of why a CAS number is not a specification. Sodium hydroxide production uses one of three main chlor-alkali routes: mercury cell, diaphragm cell, or membrane cell. According to Euro Chlor, the European chlor-alkali industry has progressively shifted away from mercury and diaphragm technologies to membrane-cell production.

Why does the route matter? Because it changes the impurity profile. Mercury-cell caustic can introduce trace mercury; diaphragm-cell caustic tends to contain more sodium chloride and chlorate. If the material is used in a pharmacopeial process or for cleaning validation, route changes can affect analytical results.

Ask every potential supplier: “Which manufacturing site produces this material, and which chlor-alkali process does the site use?” If the salesperson cannot answer, treat it as a red flag. The same principle applies to other supposedly identical commodity chemicals.

3. Decode TOC before relying on it

The first time a pharma supplier sent me a water certificate, I paused at the acronym. TOC full form in pharma is Total Organic Carbon. It measures the concentration of organic carbon in samples such as purified water, water for injection, and cleaning-validation rinsates.

If a supplier certificate says “TOC: Pass,” ask three questions: Pass what limit? Pass by which method? Pass on which sample? According to USP General Chapter 643, TOC is used to monitor organic impurities in pharmaceutical water. It is not a bioburden test and it does not detect inorganic contaminants.

I have seen certificates where TOC was measured on the rinse water rather than the final product. For cleaning validation, that can be the right sample. For release of water, it is not. Ask for the sampling point in writing before relying on the result.

4. Treat supplier ownership changes as a quality event

Procurement checklists rarely include press releases. They should. Divestitures and acquisitions change the company that owns your supplier agreement, and that change is a risk to your approved status.

A useful public example is the conversation around IFF and its pharma solutions business. When the divestiture was announced, financial reports referenced an EBITDA multiple of 13x. The exact number is a finance question; the procurement question is what the new owner does to earn that multiple.

A buyer that acquires a pharma solutions unit at 13x EBITDA is not paying for stability. It may be paying for margin improvements, cost synergies, or portfolio fit. In practice, that can lead to site consolidation, SKU rationalization, and new contract priorities. If your raw material comes from the divested business, your quality agreement, audit rights, and even the site address in your regulatory filings may need to be revisited.

After any supplier M&A announcement, ask three questions:

1. Does the transaction cover the legal entity and site that produce my material?
2. Will my existing supply agreement and quality agreement transfer to the new owner?
3. Are the manufacturing addresses and regulatory references in my product dossier still valid?

5. Verify the site, then verify the paper

A certificate of analysis is only as trustworthy as the site and the people behind it. Before the first order, I ask for the list of manufacturing sites and the testing locations. Then I ask for a copy of the COA for a lot already in the market. If the supplier cannot provide a clean and complete certificate within 24 hours, the first production order is not likely to be smoother.

Check the certificate for the lot number, manufacturing date, expiry date, specification, method reference, results, and signature. Missing fields are not administrative details; they are red flags. Look also at the legal entity. If the COA was issued by a repackager rather than the manufacturer, the repackager’s certification matters as well.

6. Bargain for change-notification rights before the price

The most valuable clause in a preventive procurement checklist is the one that makes silence expensive for the supplier. I now put a change-notification obligation into supplier agreements. It should cover:

• changes in the manufacturing site;
• changes in the production process, such as a shift in sodium hydroxide production from membrane cell to another route;
• changes in the source of critical raw materials;
• changes in analytical methods or certificate content;
• changes in ownership or legal entity.

If you do not ask for this, the supplier may meet every product specification and still disrupt your supply chain through an unannounced process change. A written notice period gives you the time to revalidate before the next batch is shipped. Prevention is cheaper than rework, but only if you know about the change before it reaches your dock.

Common mistakes after the checklist is complete

The list above comes from my work in specialty chemical formulating. If you buy for a different segment, your technical review will go deeper. The precaution still applies: identify the active, verify the process, decode the acronym, watch the ownership, insist on the site, and document changes.

Common mistakes I continue to correct:

1. Searching by brand name instead of active ingredient when checking for paraquat products.
2. Comparing caustic soda prices without asking about sodium hydroxide production route.
3. Accepting a TOC result without knowing whether TOC in pharma means Total Organic Carbon on purified water or a cleaning-validation sample.
4. Hearing about a divestiture like IFF pharma solutions and thinking it has nothing to do with procurement until the contract arrives.
5. Buying from the lowest-priced supplier before verifying whose site issued the certificate and whether the repackager has its own GMP certification.

Five minutes of verification beats five days of correction. That phrase is not motivational; it is just the math I have watched play out across eight years of purchase orders. Do the checks before the PO. The plant floor will have fewer surprises.