Tuesday, July 29, 2014

Batch Code Basics

Batch Code Basics
When Your Makeup Was Made and When You Should Throw It Out

  1. What is a batch code? How is it different from an expiration date?
  2. Where do I find the batch code?
  3. How do I read a batch code?
  4. What if the batch code is unusual and doesn't follow the aforementioned format?
  5. What about expiration dates and "shelf life"? When should I toss my products?
  6. How do I know if my product is rancid?

In spring of 2014, I initiated a swap: my MAC blush palette, near full with 5 practically pristine MAC powder blushes, in exchange for two NARS foundations: one in a screw-top bottle and one in a pump bottle. I received the NARS foundations relatively quickly and, on the outside, they looked perfectly fine. Despite minor quibbles with the swap, we finalized and exchanged tokens.

Then I patch tested the foundation in a pump bottle and opened the screw-top bottle foundation to take a whiff. I immediately noticed that the foundation in a screw-top bottle, Sheer Glow, was rancid. A few days later, I developed a mild chemical burn on my chin, which my dermatologist said was most likely caused by my patch test of the other foundation. Feeling I'd been duped, I checked the batch codes...and sure enough, these foundations were 5+ years old.

I have since added the following note to my MakeupAlley.com swap notepad: "As of April 2014, I will NOT swap with any MUAer who refuses to provide batch codes for my products." I know that this will help prevent me from swapping for another product that is too old for my tastes.

1. What is a batch code? How is it different from an expiration date?

Companies that want to make money can't possibly afford to make their products one at a time. Instead, they mix vats of the necessary chemicals and pigments, then pour this vat o' stuff in to multiple containers. This is a batch. Depending on the size of the company, a batch may consist of a hundred bottles of the same product or thousands of bottles of the same product. For example: NARS may mix a large amount of Sheer Glow foundation in the shade Fiji, then pour it in to 100 bottles; this is a specific batch of NARS Sheer Glow. If NARS mixes another vat of Fiji three months later, that is a different batch.

To designate which vat o' stuff filled the containers at a certain time, the containers are marked with a batch code. Batch codes are usually a series of letters and/or numbers; these letters and numbers represent when the batch was made.

The difference between a batch code and an expiration date is simple. A batch code indicates when a product was made. Companies can use batch codes to track how well a product sells at certain times of year, to maintain quality control, and to enact a recall when necessary. Meanwhile, an expiration date is an estimation of when the product will "go bad." Essentially, this is when the manufacturer believes the product should be replaced.

2. Where do I find the batch code?

In most cases, the batch code can be found on the actual product container. Here is the batch code on the NARS Sheer Glow I swapped for, printed on the bottom of the bottle: 9SEDA. You can tell it's a batch code because it's not part of the circular label, it's printed in a different font, and it's a seemingly nonsensical collection of letters and numbers (as compared to the numbers and letters indicating product size, "1 Fl. Oz.").

Batch codes aren't always this easy to spot, however. I've actually owned products where the batch code was on the outer packaging, but not the actual container. There are also plenty of companies that print their batch codes in ink that's the same color as the bottle, making it incredibly difficult to read. You'll notice the latter on a lot of NARS' black, rubberized packaging: the batch code is in black ink on a black background, and you can only find/read it if you tilt the bottle in the light to catch the sheen of the ink.

Why do companies do this--are they trying to dupe you? Eh, not likely. The truth of the matter is that batch codes are...kinda ugly. So companies sometimes get in to the habit of hiding the batch code in plain sight.

Here's a tube of Too Faced Shadow Insurance. See the batch code? (Look closely!)

The batch code isn't inked on this tube. Instead, it's imprinted on the plastic at the very end of the tube. Because the letters and numbers are the same color as the tube, and because the batch code is surrounded by a bunch of texture that could be confused for letters/numbers, it's a bit hard to read. But it is there!

I highly recommend that everybody get in to the habit of looking at their recent beauty purchases and checking for a batch code. If you cannot find a batch code and/or it is only located on the outer packaging, make a note of when you purchased the product and consider contacting the company for more information.

3. How do I read a batch code?

Just like every company has their own packaging style, sales pitch, and pricing justifications, every company has their own unique batch code formula. One tip I can give you, however, is that most companies want batch codes to be easy to read and hard to screw up. The overwhelming majority of beauty companies use a letter/number to represent the last digit of the year a product was made, and another letter/number to represent the month a product was made OR which specific batch mixture the product comes from. If there are many numbers/letters in a batch code, it's usually the first and last symbol that count. The reason so many companies use this formula is because, again, it's easy to read and hard to mess up.

Let's use Rimmel and MAC as an example.

On the left, we have a tube of Rimmel Scandal Eyes Retro Glam mascara. It has a 4-digit batch code: 4052. My educated guess is that the first and last number, 4 and 2, are the important parts of the batch code. With that in mind, I can start breaking down what these numbers might mean:
  • YEAR: 4 or 2 was the last digit of the year, so the mascara was made in either 2014 or 2012.
  • MONTH: April is the 4th month of the year, February is the second. One of the numbers may represent the month, or it could represent...
  • BATCH: This mascara may have been from the fourth batch made that year or the second batch made that year.
Rimmel Scandal Eyes Retro Glam is a relatively new mascara, so I can assume that the first number represents the year my tube was made: 2014. That means the last number, 2, either represents which batch my tube comes from, or the month my tube was produced in. Hence, my mascara was made in February 2014 or comes from the second batch produced in 2014. A quick Google search on how Rimmel's batch codes work proves that, yes, my mascara was made in February 2014.

MAC labels indicate all three pieces of information: the year and month the product was made in, plus which batch the product is from. This isn't surprising if you consider just how popular MAC is and how much product they would have to mix and fill to keep up with demand. So let's decode my tube of Please Me lipstick: the batch code is A23. Considering when I purchased this lipstick, and combining that knowledge with a Google search on how MAC calculates batch codes, I quickly figure out that MAC's formula is "batch, month, year." Hence, my Please Me lipstick is from the first batch (A) of February (2) 2013 (3).

Bear in mind that most companies will "recycle" letters and numbers that represent the year as is necessary. For example, let's say you swap for a product that has been in production for over 40 years. You notice that the batch code is "6B," with 6 representing the last digit of the year it was produced and "B" representing the month. With that in mind, the product could have been produced in February 2006...or it could've been produced in February 1986. Checking the product for signs of rancidness (discussed later in this article), asking the swapper when they purchased/received the product, and keeping abreast of packaging changes throughout the years can help you figure out just how new the product is.

4. What if the batch code is unusual and doesn't follow the aforementioned format?

While I was researching this article, I flipped over just about every piece of makeup I know, encountering easy-to-read batch code after easy-to-read batch code. Then I looked at my Hourglass Opaque Rouge Liquid Lipsticks.

 I'm not an insanely huge fan of most Hourglass products--they just don't suit me--but this is probably one of my all-time favorite lipstick formulations. And I greatly respect the company; they seem to take great pride in maintaining a small range of high-quality products, and I hear wonders about their customer service. Surely, a company that's so science-y is going to have a very easy-to-read batch code!

Note: the HG batch code is actually pretty easy to read in real life, but the metallic tubes tend to photograph darker than they really are.

KBL. What the heck is KBL?! There aren't any numbers here! And cripes, which letter is representing what?!

Faced with a conundrum like this, I recommend two courses of action.

1. Use a batch code-reading website. These are websites that have obtained the batch code formulas various companies use, programmed them in to a sort of calculator, and provided the calculating service to the general public. It sounds fancier than it looks: you go to one of these websites, plug in the batch code, "hit enter," and it tells you what the batch code means.

The batch code readers I use most are CheckCosmetic.net and CheckFresh.com. Both of these websites allow you to choose from a number of brands on a drop down menu. Then you just type in the batch code, hit enter, and boom! There's your information. Other batch code readers that are generally reliable: CosmeticsWizard.net (smaller brand list) and Cosmetic.Momoko.hk (Chinese website, but pertinent information is in English).

I recommend that you use batch code reading websites to double-check your own deductions, even if a company uses very simple batch code formulas. Even though MAC batch codes, for example, are stupidly easy to read, I'll often use a website like Check Cosmetic to ensure that I didn't misread something or make a mistake.

2. Contact the company. I couldn't find Hourglass on my favorite batch code readers, so I went to the company's website and sent them an e-mail via their "contact" form. I told them that I couldn't figure out how Hourglass' batch codes work, then provided them with the batch codes listed on two of my liquid lipsticks. They responded back in just a few days: the second letter in the code represents the last digit of the year, and the third letter represents the month. So KBL equals December (L = 12th letter of alphabet) of 2012 (B = 2nd letter of alphabet).

As an added bonus, this can give you insight in to how great a company's customer service is. The response from Hourglass was incredibly quick and very cordial, so they get brownie points!

5. What about expiration dates and "shelf life"? When should I toss my products?

This section of the article is going to be, without a doubt, one of the most controversial things I've ever written. I need to clarify that you're going to read an explanation of "shelf life" symbols, followed by standard "when to toss" dates provided by several websites, followed by my own personal "when to toss dates." Please bear in mind that this last section of information is based partially on my own personal beliefs as a makeup collector who takes extra precautions to ensure her products stay viable longer. How long you decide to keep your makeup is ultimately your own personal decision.

With that in mind, let's explain cosmetic shelf life.

 "Shelf life" is technically defined as "the length of time for which an item remains usable, fit for consumption, or saleable." In simpler terms, it's  how long you can keep a product before it's considered too old to use. Most professional (ie, non-indie/small company) cosmetic brands use a symbol--an open jar with a number on it--to represent shelf life. The above Becca Beach Tint has a listed shelf life of "12M," or 12 months from the day it's first opened.

Some people claim that shelf lives are designed to sell more product, ie, by claiming that you should replace a product every year instead of keeping it until you run out, the company gets you to buy a new product every year versus every 3-4 years. While I can't verify if that's a legitimate sales tactic, most people will tell you that the shelf lives listed on products are, at the least, very conservative. Take this Beach Tint as an example: one year is not much time to own and use a product. Also, consider that the product is in very sanitary packaging: you squeeze the desired amount of blush out via a nozzle, so there's no need to dip your fingers in or let the whole tube come in to contact with the air and bacteria. True facts, I've been using this particular tube for almost 3 years now, and I've yet to have a problem.

I'm a makeup addict, though, not a casual user. I'm also obsessively clean. If you do not keep your makeup and brushes clean and/or if you do not ensure that you're being sanitary when you apply your products, you may want to heed listed shelf lives.

You could also follow the standards set by some dermatological professionals.This list combines information from InStyle magazine and Dr. Bailey's Skincare Website, but the listed time frames are commonly used in books, magazines, and websites:

Nail Polish: 1 year
Mascara: 3 months
Sunscreen: 1 year
Face Cream: 1 year
Fragrances: 2 years
Power Products: 2-3 years
Liquid Foundation: 1 year
Lipstick and Gloss: 1-2 years
Pencil Liners: 2 years
Liquid Liners: 3 months

My "personal shelf lives" are based on my lifestyle and personal preferences. Namely, I refrigerate all of my foundations when they hit the one-year-old mark, I keep my brushes extremely clean so that oils from my face don't mix in with my products, and I always wash my hands before I apply my makeup. I spritz my collection with alcohol once a month to keep everything super-clean and to prevent bacteria from festering. This is not the behavior of a casual makeup user, so I do not follow the same rules as a casual makeup user.

I also follow the example of many an industry expert and assume that a well-cared for powder can last for decades because it does not contain moisture. Also, perfumes can remain fresh and stable for decades if they are kept in cool, dark places (hence the booming vintage perfume market). This means I have some powders and perfumes in my collection that are well over 5 years old. I've had some lipsticks that lasted for more than a decade, and other lipsticks that went bad after less than a year; with lipstick, I just check for signs of rancidness (see below). I do change my mascara every 4-6 months, but this is partially because the mascara tends to have dried up and become unusable by that point.

I personally believe you should toss your products when they go rancid (ie, the chemical composition changes), if they're liquids that are over 2 years old and have not been refrigerated, if they're clearly dirty or ruined, or if you do not feel comfortable using a product that is "of a certain age." This is my personal creed, but again, consider your own lifestyle and makeup habits, and go from there to come up with a set of rules you feel comfortable with.

As a sidenote, the expiration dates and shelf lives of sunscreens are something I tend to take at face value. Sun protection is, in my opinion, of the utmost importance, and I always toss my sunscreens once they're past their listed expiration date and/or hit the two-year mark.

6. How do I know if my product is rancid?

Let's be honest: there's always a chance that your makeup has gone bad and you don't know it. In many cases, however, products will go bad in a tangible way. The makeup community tends to refer to these turned products as "rancid."  This may seem like a odd word choice, since rancid is usually used to describe food that has changed flavor, scent, or texture and become stale or inedible. But makeup, like food, is a study in textures, smells, and colors, and nobody wants a product that has chemically changed and is now "unusable."

Here are some common signs that your product has turned rancid.

1. The texture or color has changed. This is common with liquid foundations and concealers. Over time, they may become thicker or thinner, develop chunks, or separate so badly that even a good shake won't redistribute the pigments. Blushes and highlighters often change color when they start to go bad. If a product suddenly feels or looks different, give it a sniff, because...

2. Rancid products tend to lose their smell, or take on a very different smell. MAC lipsticks are known for their distinctive vanilla fragrance; when they suddenly stop smelling like vanilla, it's assumed that the chemical composition of the lipstick has changed. Products may also develop a new fragrance, or they may start to smell very different. That's how I knew the bottle of NARS Sheer Glow I mentioned at the start of this article was bad: it had a very sharp, unpleasant chemical smell. While fresh bottles of NARS Sheer Glow do have a scent, I know that it's quite different from the rancid smell wafting from the bottle I'd obtained in a swap.

3. You used the product when you had an infectious infection. Examples include lipsticks used during an outbreak of oral herpes, or mascaras used right before you contracted pink eye. Although these products may look, feel, and smell fine, they may still be carrying around germs, and if you use them again, you could re-infect yourself. It's not worth it, my friends.


  1. This is incredibly useful, thanks for the info. Imma share this on twitter x

  2. Terrific article, thanks - although it's also a very expensive article for me. I'm calculating how much makeup I'm going to have to pitch now.....

    1. Again, it's all based on your personal choices. I have lipsticks that are pretty frickin' old that I still use, whereas some people will toss a lipstick after 1 or 2 years. The choice is yours; I just tried to outline the options! :)

  3. Wow. Definitely one of the best posts I have read in a long time. It's a shame that such a bad swap prompted you to really look into this topic.


    1. It wasn't so much the swap itself, but rather the reaction I got when I talked about the swap. I realized that a lot of people don't think about batch codes, let alone try to read them. Definitely a swap that made me more wary, though, unfortunately.

  4. Well written and informative as always. I stick with the product as long as it has the same smell and texture. Except mascara. 3 months and out!

    Love the photo on the cover.

    1. Sounds very similar to my rules, and I've yet to have a problem. :) And thanks!

  5. All of the Estée Lauder companies follow the Mac batch codes :) be careful if you shop at a CCO, I just bought a Clinique cream shadow that hits the 3 year mark in 4 months. While powders may not go rancid, in my experience the binders that provide a creaminess to most often eyeshadows can seem to evaporate leaving the powder very powdery and loose. I especially find it true with eyeshadows that I have used several times vs eyeshadows that I swatched and used once. Great informational article!

    1. Thanks for the helpful comment! Yes, powders can change in texture, too, so we have to pay attention to them!

  6. Does anyone know how to read Becca Batch codes?

    1. I'm seeing a letter and two numbers on my Becca products, and the one I picked up is relatively new and has a 5 at the end. So my guess is that the last number is the last digit of the year it was manufactured. If all else fails, contact Becca.