Good Manufacturing Practices
One key part of GMP is creating and using batch numbers to keep track of each batch of product you produce. It’s pretty easy to start out simply and get into the habit.
A “batch number” is a unique identifying number (or set of letters and numbers) assigned to one product batch which can be used to identify each individual finished product made in that batch. When you assign batch numbers and put them on the products, you can just look at the product label and know immediately from which batch that particular item came.
Batch numbers are required (by regulations) on food, drugs and nutritional/dietary supplements. They are not required on cosmetics, but they are included in cosmetic good manufacturing practices and certainly are a good idea and the smart thing to do.
Why are Batch Numbers Important?
In a perfect world, you would make your product, sell the product and the consumer would use the product without a hitch or concern. And most of the time that’s what happens. However, given the way of the world and Murphy’s Law, things don’t always go according to plan. Say the color in your soap fades after a time. Or a customer says the product is rancid. Serendipity hits and that particular combination of swirl and scent becomes the best seller. What then?
Well, it’s easy if you can just look at the batch number, check records and see when the batch was made and look over the batch details. For example, in the case where the soap color faded, you could see what colors were used and hopefully determine what happened. If a customer claims the product is rancid, you could instantly determine if the product was too long on the shelf before being sold, if one of the oils used was questionable, or whether you are dealing with one of “those” customers and there really isn’t a problem at all.
Years ago, a small store that carried my products said a customer returned a jar of face cream saying it was rancid. Because I didn’t have batch numbers or “best by” labels on the product back then, I had no way of knowing if this cream had languished on the shelves in their store for over a year before they sold it, or what.
You can only determine these things with certainty IF you can track it back to a specific batch - and you can only do that if you have a batch number to track.
Assigning Batch Numbers
There are no specific rules on how batch numbers should be created or assigned - the only requirement is that there is a unique identifier assigned to each batch. In my experience, having a date embedded into the batch number helps with immediate recognition; you can instantly tell how old the product is, even without checking your records. Something as simple as the date and number of the batch for that day would work:
You could also embed additional information into the batch number making it easier to tell at first glance what the product is along with when it was made. For example, if you have several different soap formulations, you could give a special code to each formulation:
Remember, you are the only person who really needs to understand the code. So make up something that works for you and the way you think about and organize your products.
The simplest and easiest way to keep track of your batch numbers is with a log. My first batch numbers were recorded in a plain old composition book, purchased for 88¢ during a “Back to School” sale. I just wrote down the assigned batch number and what product it was:
If you are trying to go paperless, you could keep the same information in a spreadsheet or even a word processing document. Electronic files do have the added steps of having to get to your computer, open the file and enter the data. You also need to make sure that you have a back-up system in place.
Hopefully, you are already keeping a complete Batch Record for each batch you make. The Batch Record should detail everything about the making of the batch, including all the ingredients (and where they came from), quantities used, verification of measurement of the ingredients, processes used, temperatures reached, time spent, quality control, who did what, packaging used, etc. In that case, the number just gets added to the Batch Record and filed in a way you can find it again.