PFAS, or per- and polyfluoroalkyl substances, are a group of synthetic chemicals that have been linked to a variety of adverse health effects. These chemicals have been found in water supplies and foods around the world.
Scientists are still trying to understand all of the potential risks associated with them. One recent study looked at the levels of PFAS contamination in seafood, and the results were alarming.
The FDA published the results of their most recent food safety testing program. They found PFAS compounds in canned and frozen crab meat. PFAS concentrations in crab ranged from 165 to 2,227 parts per trillion. 100% of the crab samples tested were contaminated with PFAS. The FDA did not identify which brands of crab were tested.
In this blog we review PFAS and their health effects. We also discuss the FDA’s food safety testing results and what they mean for you and your family. Continue reading to learn more about this important topic.
Related articles about PFAS in our food:
Is PFAS in Canned Tuna: What You Need to Know
Does Salmon Have PFAS in it? What Are Your Risks?
Do Fish Sticks Have PFAS in Them? Surprising Results
Do Shrimp Have PFAS In Them? Shocking Answers
Does Cod Fish Have PFAS in it? A Look at the Science
Does Tilapia Have PFAS in It? What You Need to Know
What is PFAS
PFAS are a group of synthetic chemicals that have been used in a variety of industries for over 50 years. They are found in products such as non-stick cookware, water-repellent clothing, stain-resistant fabrics and carpets, food packaging, and firefighting foams. There are more than 4,000 different types of PFAS.
PFAS are very stable and do not break down easily in the environment. They can persist for years and have been found in water supplies and foods around the world. Studies have shown that PFAS can accumulate in the human body, and that exposure to these chemicals can lead to a variety of adverse health effects. This is why they are known as “forever chemicals.”
How does PFAS get in my food?
PFAS can end up in your food through several different routes.
For example, plants grown in PFAS-contaminated soil may take up the chemicals through their roots where it becomes absorbed into the bulk fibers. Livestock given feed or drinking water contaminated with PFAS accumulate these compounds in their flesh.
Similarly, fish and other seafood harvested from areas with PFAS have levels of these compounds in their bodies. This occurs through ingestion of impacted water and from eating plankton or smaller fish that have PFAS in their bodies.
When we consume these food sources, we are exposed to PFAS. This issue is compounded by the fact that these chemicals can accumulate in our bodies over time.
Health concerns and PFAS
PFAS have been linked to cancer, hormone disruption, thyroid problems, high cholesterol, and other health issues. The EPA has classified two types of PFAS – PFOA and PFOS – as “likely human carcinogens.”
The most well-studied effects of exposure to PFAS are cancer, liver damage and thyroid problems. The chemical has also been linked with immune system suppression as well hormone disruption in humans
A study found that people who regularly work with PFAS-containing materials have higher rates for certain cancers than those living elsewhere. This is an emerging area of research, and more studies are needed to understand all of the potential risks associated with PFAS exposure.
What Levels of PFAS in Food Are Safe?
The US government has not established safe levels for PFAS in our food. The EPA established maximum contaminant levels (MCLs) for our drinking water. Unfortunately, there is not a similar standard for our food.
The reason for this is that experts are unsure of how much PFAS we can consume without harmful side effects. It is difficult to precisely predict how much of a dangerous chemical people can consume before they become ill.
The experts who study the effects of poisons on humans can’t seem to agree on how to asses the risks. Various government bodies have set safety standards for PFAS.
Maine CDC standard for PFAS in food
The Maine CDC has developed a very useful guide to let you know what levels of PFAS in seafood you can safety consume. Their new chemical-specific tool is known as the fish tissue action levels (FTALs).
FTALs are the maximum concentration of PFAS in fish that is safe to consume. If the PFAS concentration is below their guidelines, you should have no risk of health effects.
Maine’s guide also accounts for the bioaccumulation of PFAS in our bodies. Their guidance includes a recommendation for how often you can eat PFAS-contaminated fish.
The table below presents the safe concentration of PFAS in seafood you can safely eat. It also notes how often you can consume it.
| PFOS in fish (ng/kg) | Meal advice |
| 3,500 | 1 meal per week |
| 7,500 | 2 meals per month |
| 15,000 | 1 meal per month |
| 30,000 | 6 meals per year |
| 60,000 | 3 meals per year |
| > 60,000 | Do Not Eat |
European Food Safety Authority standard for PFAS in food
The European Food Safety Authority (EFSA), Europe’s equivalent of the FDA, established a maximum combined intake of 4 PFAS chemicals in food. The compounds in their guidance include:
- perfluorooctanoic acid (PFOA)
- perfluorooctane sulfonate (PFOS)
- perfluorononanoic acid (PFNA)
- perfluorohexane sulfonic acid (PFHxS)
The EFSA limit for the combined total of these four PFAS compounds is 4.4 ng/kg of body weight per week.
PFAS in Crabs
The FDA conducted PFAS testing in a wide range of foods. Tests showed detectable concentrations of PFAS in fish sticks, canned tuna, and protein powder.
The FDA tested each crab sample for 16 PFAS chemicals. They found 11 different PFAS compounds in the crab meat they tested. Every sample was contaminated with PFAS.
FDA food testing methodology
It is technically challenging to measure PFAS concentrations in food. To overcome this limitation, the FDA developed a new procedure to test for PFAs in food.
The FDA’s novel test method can quantify the concentration of 16 PFAS compounds using liquid chromatography–mass spectrometry. The accuracy of their new technique was verified for the following food matrices:
- infant formula
- strawberry gelatin
- pancake syrup
- cream cheese
- shredded wheat cereal
- lettuce
- milk
- bread
- salmon
The FDA’s food testing procedure analyzes the following PFAS chemicals:
| Acronym | Name |
| PFBA | Perfluorobutanoic acid |
| PFBS | Perfluorobutanesulfonic acid |
| PFPeS | Perfluoropentanesulfonic acid |
| PFPeA | Perfluoropentanoic acid |
| PFHxA | Perfluorohexanoic acid |
| HFPO-DA | GenX |
| PFHxS | Perfluorohexanesulfonic acid |
| NaDONA | Sodium dodecafluoro-3H-4, 8-dioxanonanoate |
| PFHpA | Perfluoroheptanoic acid |
| PFHpS | Perfluoroheptanesulfonic acid |
| 9Cl-PF3ONS | Potassium 9-chlorohexadecafluoro-3-oxanonane-1-sulfonate |
| PFOA | Perfluorooctanoic Acid |
| PFOS | Perfluorooctanesulfonic acid |
| PFNA | Perfluorononanoic acid |
| 11Cl-PF3OUdS | 11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid |
| PFDA | Perfluorodecanoic acid |
How much PFAS is in crabs?
The following table presents the crab sampling results from the 2022 FDA food safety survey. These results are for total PFAS detected in crab.
| Item Description | Total PFAS |
| Claw meat | 2,227 |
| Crab claw | 778 |
| Crab jumbo | 850 |
| Crab claw | 734 |
| Special claw blend | 593 |
| Blue crab claw fingers | 165 |
| Crab lump | 1,227 |
| Blue crab cocktail claws | 226 |
| Blue swimming crabmeat lump | 1,128 |
| Blue swimming crabmeat jumbo lump | 1,062 |
| Crab meat special | 1,526 |
These results are in nanograms per kilogram (ng/kg), which is the same as ppt. If you ate 1 kilogram of the “Claw meat” – the crab sample with the highest concentration, you would ingest 251.7 nanograms of PFAS.
A kilogram is 2.2 pounds, which is a lot of crab. However, a typical serving size is 4-ounces, which is 113 grams ( 0.113 kilograms). If you eat crabs 9 times, you’ve consumed a kilogram.
How much PFAS is in crabs?
How much PFAS are you consuming when you have a portion of crab meat? Let’s take a look at the sample with the highest concentration – the “crab claw” sample.
Here is the data:
- PFAS concentration: 2,227 ng/kg
- Crab meat portion size: 4-ounces (0.113 kg)
- PFAS in serving size of crabs: 252 nanograms
What would 252 nanograms of PFAS do to your health? No one can say for sure, especially since the US has not established a maximum concentration of PFAS for food.
To help you make sense of these numbers, we can compare the FDA’s testing data to the Maine CDC standard and the EFSA limit.
Maine CDC FTAL: The Maine FTAL lists various PFAS concentrations with a corresponding limit on the frequency you can safely eat that amount of contaminated fish.
The highest PFAS concentration in the crab samples was 2,227 ng/kg. Comparing this to the FTAL table, we see that this is just below the lowest threshold of 3,500 ng/kg.
According to the Maine CDC standard, it should be safe to eat 1 meal of crab per week.
EFSA Standard: Using the EFSA standard, we have to determine how much PFAS an “average” person can safely consume. The highest amount of PFAS they established is 4.4 ng/kg of body weight per week. An average person weighs approximately 68 kilograms (150 pounds).
Here is the math: 68 kg x 4.4 ng/kg per week = 299.2 ng per week
One serving of the most contaminated crab has 252 nanograms of PFAS.
This represents about 84% of the weekly limit allowed by EFSA. Theoretically, you could eat crabs once each week without any health complications.
Despite the Maine CDC and EFSA guidance, I don’t think it’s safe to consume any PFAS given its toxicity. This is troubling, especially since I really enjoy crab.
Which PFAS compounds were found in crabs?
The FDA found 11 different PFAS compounds in the 10 samples of crab meat they tested.
These compounds are:
1. PFHpA: maximum value = 234 ng/kg
2. PFOA: maximum value = 510 ng/kg
3. PFNA: maximum value = 350n g/kg
4. PFDA: maximum value = 105 ng/kg
5. PFUdA: maximum value = 265 ng/kg
6. PFDoA: maximum value = 115 ng/kg
7. PFTrDA: maximum value = 835 ng/kg
8. PFTeDA: maximum value = 99 ng/kg
9. PFBS: maximum value = 34 ng/kg
10. PFHxS: maximum value = 242 ng/kg
11. PFOS: maximum value = 388 ng/kg
Samples were obtained from crabs harvested in two countries:
1. Mexico – 2 samples
2. Indonesia – 8 samples
The crab was packed in either cans or polypropylene. The FDA did not identify the specific brands of crabs they tested. This makes it impossible to know which brands are safe and which ones are not.
FDA statement on food safety
The FDA gave a lot of information in their report, but they didn’t provide any instructions on how to interpret the findings. The report indicates that PFAS was detected in every sample of crab, but they did not release the brand names of the crab meat they tested.
According to the FDA, their research was hampered by sample sizes that were insufficient. Because of this limitation, they could not provide an opinion on the safety of the nation’s food supply.
All of this has left many people confused and afraid.
The FDA’s main focus was that while low levels of PFAS were found in three types of food, there is currently “no scientific evidence” that the general public should be alarmed or avoid eating any foods due to these trace concentrations of chemicals.
What Can You Do
Now that you know the risks your family faces from crab meat contaminated with PFAS, what steps will you take to protect them?
The FDA indicated that the crab samples they found PFAS in were from Mexico and Indonesia. You can protect yourself by avoiding crab that comes from these countries.
You can also educate yourself about food safety so you’re aware of where PFAS might be found. A good starting point is to read my article about which products contain PFAS.
Another approach to keep your family away from contaminated food is to understand how it may become affected. The leading causes of food contamination are:
- growing food in contaminated soil
- watering plants with PFAS-contaminated water
- livestock that consume contaminated feed and water
- using PFAS-containing food packaging
- food processing equipment that includes PFAS
You should limit or avoid the following foods whenever possible:
- salmon and tuna – the top of the food-chain fish
- clams and oysters – animals that filter water for food
- microwave popcorn – it’s still packed in PFAS-containing materials
- process foods – most are packaged in PFAS containing materials
You can also regularly test your water to be certain it is not contaminated with PFAS. Read my guide on testing your water for PFAS.
Final Take
The FDA’s findings have raised some concerns about the safety of consuming crab meat. They found PFAS concentrations ranging from 165 to 2,227 parts per trillion. Every sample they tested was contaminated.
While the agency noted that it could not draw definitive conclusions about the safety of PFAS levels in crab meat and other seafood, it is still important to be aware of these potential risks.
If you’re wondering whether your favorite crab meat type contains PFAS, you should check to see whether any more testing data is available. It is also important to be mindful of food related risks associated with PFAS contamination.
Keep informed about the latest news and advisories related to this issue so that you can make smart decisions about which seafood to eat.