PBDE flame retardant chemicals in cod liver oil and canned cod liver
What it found
Cod liver oils from the Baltic Sea and North Atlantic contained PBDE flame retardant chemicals, with the highest levels found in oils from 1993 to 2001.
Canned cod liver products sold in 2017 also contained these chemicals at lower levels.
What they found
Levels in cod liver oils
Across all the oils tested, the total amount of the 17 PBDE chemicals ranged from 9.9 to 415 ng per gram. The highest amounts were found in oils produced between 1993 and 2001.
Levels in canned cod liver
Two canned cod liver foods sold in 2017 contained total PBDE levels ranging from 10.5 to 13 ng per gram. This was lower than most of the older oils.
Most common PBDE type
One specific chemical called BDE-47 was the most common in every sample. A Baltic cod liver oil from 1993 had the single highest reading of 308 ng per gram for this chemical.
Estimated daily intake
Based on recommended serving sizes, the estimated daily intake of total PBDEs from Baltic cod liver oils ranged from 2.2 to 284.8 ng per kg of body weight for adults. For teenagers it was 2.8 to 178 ng per kg, and for a child it was 2.0 to 127.8 ng per kg.
Intake from canned products
For the 2017 canned cod liver foods, the estimated weekly intake of total PBDEs was highest for adults. It ranged from 17.6 to 25.1 ng per kg of body weight per week.
What the authors conclude
- They note that unpurified cod liver oils sold before the mid-1980s were likely a major source of PBDE exposure for people who took them as supplements.
- They say that canned cod liver foods currently sold from the Baltic Sea would also lead to notable PBDE exposure for those who eat them.
- They point out that without official guidance on tolerable intake levels for PBDEs, the exact meaning of these exposure amounts remains unclear.
How it was done
PBDEs are flame retardant chemicals that have spread widely through food and the environment. Scientists had very little recent information on how much of these chemicals end up in cod liver oil supplements or canned cod livers eaten as food.
The researchers tested cod liver oils made between 1972 and 2001 from Poland, Norway and Iceland, plus two canned cod liver foods sold in Poland in 2017. They measured 17 different types of PBDE chemicals in each product. They then estimated how much of these chemicals people would take in by following the recommended serving sizes for adults, teenagers and children.
What it can’t tell you
- This work only measured chemicals in products and calculated theoretical intakes based on serving sizes. It did not measure what actually happens inside the human body after eating these foods.
- Because no health outcomes were tracked, these measurements cannot show whether taking in these amounts of PBDEs causes any effects in people.
Who paid
- Authors work at
- University of Gdańsk, Poland; University of Cartagena, Colombia(); University of East Anglia, UK
The paper
- Title
- PBDEs in cod (Gadus morhua) liver products (1972-2017): Occurrence and human exposure
- Type
- Study
- Summarised from
- Full text
- Cite
- Falandysz J, Smith F, Steel Z, Fernandes AR (2019). PBDEs in cod (Gadus morhua) liver products (1972-2017): Occurrence and human exposure. Chemosphere. doi:10.1016/j.chemosphere.2019.05.139Free full textPubMed 31152904DOI
Summary written 30 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error