The SDS That Stopped a Truck: Notes on Powder Coating, Anti-Stick Fluoropolymers, and Nitric Acid

A truckload stopped by a PDF

On a cold morning in late February 2025, I got a text from our shipping supervisor: 'Truck won't leave. The SDS is wrong.'

I assumed that meant a minor label problem. It wasn't. A customer had requested current Kemira SDS documents before the startup of their coating line. The file we sent had the right product, but it was the previous revision. Same material, different safety data.

Letting the truck go would have been easier. The launch scheduler was waiting, and the customer's line was ready. I stopped it anyway. In hindsight, I should have stopped it sooner.

You might think stopping a truck over a document is overkill. I used to think so. In 2022, a ready-to-use material was rejected because the SDS did not match the label on the drum. The material was a primer additive for anti stick fluoropolymer coatings. The chemical properties were fine. The paperwork wasn't. That mismatch cost us $22,000 in rework and rush replacement, and it delayed a customer's launch by a week. After that, I implemented a verification protocol: every SDS must match the product code, the concentration, and the current revision.

Today, at the Kemira Chemicals Marietta GA site, we follow the same rule. When someone asks for a Kemira SDS, we don't open an old PDF and hope it's right. We ask what grade they need, what concentration they are using, and where the product will go. Then we check the SDS revision against the exact product being shipped.

Powder Coating Process Explained

Why does a chemical quality manager spend so much time on powder coating? Because the process is where raw materials become a surface. Most coating failures start before the powder is sprayed.

Here is the version I walk customers through:

1. Surface preparation. Clean the part, remove oil, and create a surface the powder can grip. For stainless steel, passivation with nitric acid may be part of this step.
2. Powder application. An electrostatic spray gun charges the dry powder particles. The grounded metal part attracts and holds them until curing.
3. Curing. The powder melts, flows, and forms a film. For thermoset powders, the chemistry cross-links in the oven. For fluoropolymer powders, the oven schedule is part of the formula. Guessing is not a quality plan.
4. Testing. Measure thickness, adhesion, pinholes, and flexibility. If the coating fails, the cause is often in stage one or stage three, not in the powder itself.

That is the simple story. Real life adds ovens, part geometry, and line speed, but the logic stays the same.

The 'anti stick fluoropolymer coatings' category is not one product

The first mistake I see in technical discussions is treating that phrase like a single SKU. Anti stick fluoropolymer coatings are a family. They can be PTFE, PFA, FEP, or blends. Some are waterborne liquids, some are dry powders, and many only work with a primer underneath. If you use a cure schedule borrowed from a different powder product, you can lose the anti-stick performance before the part leaves the oven.

This is one reason I keep returning to the SDS. The SDS will not tell you whether the final surface is non-stick. It will tell you what is in the raw material, what hazards the handlers face, and what information the receiving site needs. For a Kemira chemical, the current Kemira SDS is the starting point. An old revision does not count.

Do you need a license to buy nitric acid?

This question usually appears when someone adds a passivation bath to the powder coating process. I have heard the exact question in many forms: 'do you need a license to buy nitric acid?'

Short answer: for most legitimate industrial buyers in the United States, I don't know of a federal purchase license for nitric acid in the driver's license sense. But that answer can mislead. Instead of assuming no license means no control, ask what your supplier requires and what your local authorities require.

Most industrial suppliers will want a legitimate business purpose, an end-use statement, and a physical delivery address. They may not sell concentrated acid to a residential address. Under OSHA's Hazard Communication Standard, 29 CFR 1910.1200, employees also need access to a current SDS before the hazardous chemical arrives. If you are buying a Kemira product, that means the relevant Kemira SDS for your exact grade.

Facility rules can go further. Certain quantities and concentrations can trigger federal or state programs, including process safety or risk management requirements. I don't have hard data on every local code, and I won't pretend to. What I know from audits is that spills get more attention than paper failures, but paper failures are common.

The lesson from the loading dock

Back to the stopped truck. Two hours later, it left with the correct Kemira SDS in the customer's folder. The coating line started. The test panels showed no pinholes, no adhesion loss, and the anti-stick fluoropolymer coating performed the way it was designed to.

No dramatic rescue. That is exactly the point. In technical work, quality often looks like boring, repetitive checking. The chemistry has changed and the powder coating process keeps improving, but the fundamentals remain: prepare the surface, hit the cure schedule, and verify every document before material ships.

If you are buying chemicals for a coating line, ask for the SDS before the truck arrives. If you are buying nitric acid, ask whether the supplier needs a business or end-use statement and whether your location has permit obligations. A little paperwork now beats a stopped truck later.