How & Why to Keep Lot Numbers

woman in warehouse

Last week The Nova Studio posted a great post, Why You Should Care About Lot Numbers, detailing their experiences on finding out that the San Francisco Herb & Natural Food Company in Fremont, CA had a bad rodent infestation & was recalling over a dozen of their products that may have been infested with droppings. The news report on it includes a list of the recalled items; the business is indefinitely closed.

Important Note: This is NOT the reputable San Francisco Herb Company, located in San Francisco and a reliable provider of herbs and spices to many people and companies that make handcrafted soap and cosmetics.

It can be quite a scare if you think you could possibly have a contaminated ingredient! Luckily, The Nova Studio had taped the labels on their containers of herbs, which documented the source, along with the supplier’s batch numbers (and none of their herbs were from the supplier in question).

Lot Numbers Are Required by GMP

Imagine how you’d feel if you had purchased some items from the company in question, and had spearmint leaves in your inventory. If didn’t know where they came from and what batch(es), it would mean that you’d have to toss all the spearmint leaves AND any product made from them, and you might even need to contact customers who had purchased products containing those spearmint leaves. A nightmare, to say the least.

On the other hand, if you have records of exactly where your spearmint leaves came from (and the batch numbers for them) you’d be able to tell right away if you had a problem or not.

And therein you have a real-life example of why keeping lot numbers for all incoming ingredients and materials is a key (and required!) part of GMP.

Recording Lot Numbers

Every time you receive an incoming ingredient or material (including packaging materials) it should be logged somewhere. The information to keep includes the item, supplier, date, the suppliers batch number (if any), and the lot number you assign to the batch of incoming materials (which could be either the supplier’s batch number or one that you create).

You should also note the status of the item (accepted, rejected, on hold). The status is determined after you check the item and make sure that it conforms to your required specifications, as detailed in your own Specification Sheet for the item.

The log can be kept simple, on a paper form or a spread sheet, just so long as it is kept up to date and easily accessible. Here’s an example of a sample form:

Labeling Your Inventory

When you put the incoming materials or ingredients in your inventory, it’s important to ensure that it is properly labeled, so you can tell what’s what at a glance.

I suggest a label that looks something like this:

The label should be large enough that you can see it at a glance.

Using Ingredients in Batches

Whenever you use an ingredient in a batch of product, the lot number should be noted. That way if you ever need to, you can go back and determine which batches used a particular product lot.

Good Manufacturing Practices Help You

Keeping lot numbers for all your incoming ingredients and materials, and noting when those ingredients and materials are used in product batches, is required by GMP. But even more importantly, it’s a way to give you peace of mind if you ever find that you have received potentially contaminated product.

GMP is all about making sure that your products are of the highest possible quality, every batch, every product, every time. And that’s what you want, right?

If you have questions about what GMP requirements are (or how to implement them) feel free to submit your question and/or purchase Good Manufacturing Practices for Soap and Cosmetic Handcrafters from Amazon using the button below.

Good Manufacturing Practices cover

Every handcrafter’s situation is different. To work out the good manufacturing practices that will work for you, get my book from Amazon and use it.


8 responses to “How & Why to Keep Lot Numbers”

  1. labeling book needed ,labeling requirements and GMP BOOK

    1. Both books can be ordered from Amazon and are shipable internationally. Search “Marie Gale” at Amazon and you should find them.

  2. Do you mentioned lot numbers for bottles. Can you elaborate on that? I can’t wrap my head around how to do that part.

    1. Marie Gale

      All ingredients and materials used in your product should have lot numbers. Including bottles.

      So let’s say you order some bottles from a new supplier. You receive the bottles and assign a lot number to them. If you have a lot number from the supplier, keep track of that as well. When you make your batch, you note which lot number of bottles (and closures) you use. Just like you do with the ingredients.

      The reasoning is that in the unlikely event that the supplier comes back to you and says, “Oops, we discovered we had the wrong plastic in those bottles, and they are going to split at the seams when they get too hot,” you will be able to find (and return) the sub-standard bottles. If you don’t have lot numbers you might end up with lots of bottles and no way to know which might fail. Again, just like ingredients.

  3. Thanks for the information…I have your book on labeling requirements and definitely want to get the GMP one too. As someone who grows a lot of herbs and is thinking of using them in bath products to sell, how would you recommend keeping track of lot numbers for a single herb that you are drying in several batches, potentially over several weeks (or even months) of the growing season? It seems impractical (not to mention costly) to have four or five different jars of spearmint with five different lot numbers taking up space, when they all came from your garden, just at different times. Any advice?

    1. Marie Gale

      I’n not familiar with the standards for growing herbs or other foods and recording information about them. I would think, however, that if there is any significant difference in the batches picked, that they should be separately recorded so you can track back if there is any problem.

      For example, if you pick at different times of the day/week/month and it could affect the moisture content of the herbs, then that could potentially affect the necessary drying times or even your cosmetic product. In that case, it might be good to have a record that a particular batch was picked at a certain time of day or in certain weather conditions, or that it was dried in a particular way and for how long (and under what conditions). That way if you have differences, you can tell what might be the cause.

      It’s not dissimilar to people who order a product from a particular supplier and then order the same product from the same supplier a month later. It’s virtually identical (and might even be from the same product lot that the supplier received, but it still needs to be recorded as a separate lot for the purposes of the person who receives it.

  4. Great article! love the examples…working my way through your GMP book…loads of info and I love it! – thank you!

  5. Awesome post, Marie! We are super excited about your upcoming GMP class on October 14 at The Nova Studio!

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