It is one of the commonest complaints in chemical buying, and it is almost always preventable. The fix is not a better supplier promise. It is agreeing a few things in writing before the order.
The short answer. Agree the specification in writing, not just the sample. Keep part of the approved sample sealed as a reference. Require a batch certificate of analysis for the bulk and check it against your specification. Test the bulk on arrival. And agree in the purchase order what happens if it is off specification.
A sample is one small portion of one batch. A bulk order may come from a different batch, made on a different day, from a different lot of raw material. If the only thing agreed was ‘the same as the sample’, there is nothing precise to hold the bulk against, and two people can look at the same result and disagree about whether it matches.
1. A written specification. List every parameter that matters to your process, with a limit for each. This is what the bulk is judged against, not the sample.
2. A sealed reference sample. Keep part of the approved sample sealed and labelled. If there is a dispute later, both sides can test the same reference.
3. A certificate of analysis for the bulk batch. Not the sample’s certificate. The bulk batch’s own, with its batch number matching the bags.
4. A test on arrival. For a first bulk order especially, test the consignment before it goes into production, using the same method as the specification.
5. What happens if it fails. Write it into the purchase order: how a failure is confirmed, and what the remedy is. Agreeing this before there is a problem is far easier than after.
It does not need to be long. It needs one row for each thing your process depends on, a limit you will accept, and the basis the figure is measured on. For example, a buyer of a zinc micronutrient might write:
| Parameter | Limit | Basis |
|---|---|---|
| Zinc content | Not less than the agreed minimum | As Zn, by weight |
| Moisture | Not more than the agreed maximum | By weight |
| Solubility | As agreed for your process | At the stated temperature |
| Packing | 50 kg net, HDPE bag | Per bag |
This is an illustration of the format, not a specification for any product. The parameters and limits are yours to set for your own process.
Taskon publishes one grade for each product on its product page, sends the signed Material Safety Data Sheet with the quotation, and sends a batch certificate of analysis with every consignment. Send your specification with the enquiry and we will tell you, before you order, whether we can supply against each parameter in it. If we cannot meet one, we will say so then.
Know what you need already? Send the grade, the quantity and the delivery location and we will quote against them.
Send us the product, the quantity and where it is going.