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Are There Microplastics in Your Plant Milk?

Are There Microplastics in Your Plant Milk?

Microplastics, they’re the current hot topic in health and while we still don’t know much about them we do know that they’re everywhere. Microplastics are in our food, water and even the air. However, it’s not all doom and gloom! As more information comes out, we’ve learned that there are ways to greatly reduce the amount of microplastic you consume (check out “5 Ways Microplastics May be Sneaking Into Your Life & How to Easily Avoid Them” for some examples). One of the most impactful ways is by being conscious of the foods you consume, particularly how their packaging and preparation may impact their microplastic load. So how does plant milk fit into this? How much microplastic is in plant milk? Where is that microplastic coming from? Is store-bought more contaminated than home made plant milk? 

In our efforts to answer these questions, we realized that unlike dairy milk, there’s practically no data on microplastics in plant milk. If we wanted answers, we would have to gather our own data, so we sent samples of almond milk from 3 different brands (including our own) to labs that could analyze them for microplastic! Almond Cow is proud to present the first publicly available data on microplastics in plant milk, and we promise the results will shock you!

 

How Would Microplastic End Up In Plant Milk?

Before we dive into the test results, let’s go over how microplastics would even end up in your plant milk in the first place. 

If you’re blending up your own almond milk at home, microplastics could be introduced via the water you use; the almonds themselves could be dusted in plastic fibers from the shelling and packaging process; and plastic particles can even be sheared from your blender’s pitcher due to the high speed friction of being pelted by hard ingredients. However, almond milk found at the store has even more potential to be polluted as every step along the production line introduces an opportunity for contamination: 

  • Raw ingredients can be transported in plastic sacks or harvest bins

  • Machinery and workers’ clothing/protective gear can shed microplastics

  • The milk and its packaging are typically sterilized using high heat, which can degrade plastic polymers and increase the likelihood of microplastic leaching; particularly if the milk isn’t cooled before being poured into cartons/bottles

  • The packaged milk is transported to stores or a warehouse usually over long distances and subjected to heavy vibration and various temperature changes which can cause further leaching

 

It’s no wonder researchers are finding a link between microplastic levels and how heavily a food is processed!¹,²


How Did We Test Plant Milk for Microplastics?

For our store-bought samples, we decided to test almond milk (the most popular plant milk in the US) from 2 popular plant milk brands: Silk’s Unsweetened vanilla almond milk and Califia’s Unsweetened almond milk. We sent an entire unopened carton of both of these shelf-stable milks to Measurlabs for a microplastic analysis that would not only tell us how much but also what type of microplastic was present. Of course we had to know how our own milk stacked up, so we made almond milk in the Almond Cow with our own bee-friendly almonds and Primo filtered water. This Almond Cow sample was shipped to SimpleLab for their microplastic analysis. 

Hold on, why did we use two different labs? Unfortunately, we found out that Measurlabs couldn’t accept samples at their US location unless they were shelf-stable, and as awesome as our milk is, shelf stable it is not! So we then had to find a lab capable of accepting perishable samples which is where SimpleLab comes in. Their microplastics test wouldn’t be able to tell us what type of plastic was present, but would be able to detect microplastics at a much more sensitive degree than the Measurlab’s test and we were up to that challenge!


The Results!

The microplastic counts were reported by size class, and since we’re dealing with microplastics, microns, or micrometers (μm), were the unit of length used. One micron is equal to one-millionth of a meter and is small enough to be invisible to the human eye. As we go over the results, we’ll be sure to provide some everyday examples to put these measurements into perspective. While both labs used the same size classes, they did use different concentration units: Measurlabs reported their microplastic counts as “number of particles per 0.5 g” of sample, whereas SimpleLab reported their results using “particles per milliliter”. To make comparisons more straightforward, we decided to standardize all results to “particles/0.5mL,” since 0.5g of plant milk is equivalent to 0.5mL.  

That’s right, our Almond Cow sample was reported to have no detectable amounts of microplastic despite being tested by a much more sensitive analysis method! You’re probably wondering how comparable these results truly are since they came from two different labs, and we’ll cover that in full detail further down. But for now let’s take a closer look at the results for the Califia and Silk samples.

Plenty of microplastic particles were found in both store-bought samples ranging from 10-500μm in size with most particles falling in the 10-50μm range. For reference, a human blood cell has a diameter of 7-8μm and a sheet of printer paper is about 100μm thick. Interestingly, the Califia sample contained over 6x more microplastic particles than the Silk sample! But why? Let’s take a look at what type of plastic these particles consist of to see if we can figure out where they might have come from.

Four different types of plastic were found in the Califia sample while the Silk sample was a little more diverse consisting of six types. Most of these categories only include 1 or 2 particles, so let’s focus on the main contributors: Polypropylene (PP) and Polyethylene Terephthalate (PET). Both milks were packaged in TetraPaks which are internally lined with polyethylene (PE), and have caps that can also be made of PE or a recycled polymer blend. No PE particles were identified in either sample, and even if the caps are made of a recycled polymer blend, they’re unlikely to shed much microplastic from being tightened and untightened only once or twice.

So if the microplastic isn’t coming from the packaging what about the water? We know there’s microplastic in our drinking water with studies finding most particles found in tap water consist of PET, PP & PE³, and while the concentrations reported in those studies vary greatly they all tend to be much lower than what we’re seeing in these plant milk samples. In fact the highest reported average concentration found in tap water according to a 2022 scientific review was 440 particles/L (or 0.22 particles/0.5mL)⁴. Meaning, these microplastics are finding their way into the plant milk somewhere else along the processing line!


How Comparable are These Results?

Because we had to use 2 different labs, the store-bought samples and our Almond Cow sample were processed in slightly different ways. Let’s go over those differences in detail to get a better understanding of how comparable these 2 test reports truly are:

First, let’s go over how the samples were collected: We sent Measurlabs entire unopened cartons of Califia and Silk to avoid any  environmental microplastic contamination. Our Almond Cow sample was freshly poured straight from the stainless steel carafe into a glass bottle with a plastic lid that was provided to us by SimpleLab and guaranteed to have minimal microplastic exposure.

Next let’s consider how the samples were analyzed: both samples were digested to break down the organic solids and then sieved through various sized filters to capture microplastics while simultaneously organizing them into different size classes. Those filters were then examined under a microscope for the presence of microplastics. Measurlabs filtered and analyzed 0.5g (~0.5mL) of each store bought milk while SimpleLab filtered and analyzed an entire 500mL of our almond milk!

The biggest difference between the two labs is the analysis method that was used to identify microplastic particles: Measurlabs utilized a chemical analysis technique known as Raman spectroscopy while SimpleLab used a powerful imaging technique called fluorescent microscopy. 

To keep it simple, Raman spectroscopy involves shining a laser onto the material of interest and measuring how light scatters off of that material to identify its chemical composition. This is why the microplastic particles in the Califia and Silk samples were able to be identified by plastic type. On the other hand fluorescence microscopy involves exposing samples to fluorescent dyes then shining light onto them to produce a high-contrast image allowing for detailed visualization of the sample.

 While both methods involve exposing samples to light and measuring the light that’s emitted back, Raman spectroscopy is better for identifying chemical composition while fluorescent microscopy is much faster and more sensitive. In fact, let’s consider the sensitivity reported by each lab: the Limit of Detection (aka the lowest concentration of microplastic that can be measured) by Raman spectroscopy varies depending on particle size class and plastic type, but overall it ranged from 2-8.6 particles/mL of sample. Whereas SimpleLab reported the limit of detection for their fluorescent microscopy as 0.002 particles/mL! 

All of this is to say that while it wasn’t ideal to have to use two different labs, the Almond Cow sample was subjected to a much more thorough and sensitive analysis yet was still found to be microplastic free!


Main Takeaways

Ultimately, here’s what we learned from these tests:

  • There’s microplastic in the plant milk sitting on store shelves; how much can vary greatly from brand to brand

  • The microplastics found in the Califia and Silk samples aren’t coming from the plastic packaging, and we know it’s way more than what’s typically found in drinking water. Unfortunately we don’t have enough information to say where it’s coming from.

  • The almond milk made in the Almond Cow was microplastic free. This suggests that making your own plant milk allows you to greatly control how much microplastic it comes into contact with! In fact, if you use triple filtered water and a milk maker with stainless steel milk contact points, your plant milk can be microplastic free!

 

Want to read the full reports for yourself?

Measurlabs - Silk and Califia test report

SimpleLab - Almond Cow test report


TL;DR? Don't worry we also made a video covering these results!

 


Sources

1. Fabiano, Nicholas, et al. "Microplastics and mental health: The role of ultra-processed foods." Brain Medicine 1.3 (2025): 31-33.

2. Lin, Qianhui, et al. “Potential risk of microplastics in processed foods: Preliminary risk assessment concerning polymer types, abundance, and human exposure of microplastics.” Ecotoxicology and Environmental Safety 247 (2022): 114212.

3. “Microplastics in drinking-water.” Geneva: World Health Organization (2019)

4. Gambino, Isabella, et al. "Occurrence of Microplastics in Tap and Bottled Water: Current Knowledge." International Journal of Environmental Research and Public Health 19.9 (2022): 5283.