‘Organic’ salmon sold in UK supermarkets exposed to harmful chemicals

The Green Britain Foundation (GBF) is warning consumers about the potential risks linked to so-called “organic” salmon being sold in major UK supermarkets.

A GBF investigation has uncovered serious flaws in the certification process that have allowed routine use of toxic chemical treatments on organic salmon produced by the world’s largest salmon company, Mowi, and sold by Sainsbury’s, Tesco, and Ocado.

The Soil Association (SA), the UK’s leading organic certifier, has since admitted to a “weakness” in its standards for organic salmon farming, which permitted the use of harmful substances that directly contradict public expectations of what “organic” should mean.

Toxic treatments exposed

Using open-source data from multiple organic salmon farms, GBF found that Mowi’s supposedly organic fish were routinely treated with banned and harmful chemicals, yet still sold to consumers under the organic label.

These chemicals include:

• Deltamethrin: a highly toxic synthetic pyrethroid insecticide, 360 times more toxic than DDT, used to control sea lice but known to devastate aquatic ecosystems and non-target species.

• Emamectin Benzoate: a neurotoxic antiparasitic chemical from the Avermectin family, banned by the Soil Association due to its broad toxicity to mammals, birds, fish, and aquatic plants.

• Azamethiphos: an organophosphate insecticide linked to neurological disorders and male infertility, also banned by the Soil Association for its “acute toxicity” and “detrimental effect on marine species” (Soil Association aquaculture standards, page 53).

GBF analysis shows that fish treated with these substances are being sold as organic, even though they do not meet the Soil Association’s updated 2024 standards, a fact the Association has now confirmed.

Certification loopholes and consumer deception

Under the previous Soil Association rules, non-organic salmon farms could convert existing stock to organic status after just three months, without accounting for prior chemical treatments.

This loophole enabled salmon treated with toxic substances to enter the market as “organic.”

The Soil Association has since acknowledged this as a weakness and revised its standards in July 2024, now requiring that organic salmon must be organic from birth, with fish sourced as organic juveniles and kept under organic conditions throughout their lives.

However, GBF’s investigation found that fish treated under the old regime are still being sold and the Soil Association has admitted that these products will remain on sale into early 2025, despite failing to meet current organic standards.

GBF statement

Dale Vince, founder of the Green Britain Foundation, said:

“This scandal with so-called ‘organic’ salmon is just the tip of the iceberg. Not only are consumers being duped into paying premium prices for farmed salmon doused in toxic chemicals, but the entire practice of fish farming is an environmental disaster.

It’s polluting our oceans, decimating wild fish populations, and causing immense animal suffering. The idea that any of this could be considered ‘organic’ is as absurd as burning fossil fuels and calling it green energy.

We need to move away from these harmful practices altogether and embrace alternatives that are truly sustainable and ethical. It’s time we stop exploiting our oceans and start protecting them.”

Key findings at a glance

1. Harmful chemicals: “Organic” salmon have been exposed to deltamethrin, emamectin benzoate and azamethiphos; all toxic and environmentally damaging.

2. Certification loopholes: The Soil Association previously allowed farms to convert existing non-organic stock to organic status within three months.

3. Consumer deception: These practices contradict consumer expectations and erode trust in the organic label.

4. Standard updates: New rules (July 2024) close this loophole — but affected fish remain on sale into early 2025.

Data sources and analysis

GBF reviewed treatment data from four Mowi-owned organic farms, including Camas Glas, showing extensive use of the banned chemicals listed above.

View the analysed data here

The fish produced from these farms are sold through Sainsbury’s, Tesco, Ocado, and Mowi’s own brand products.

For video of salmon at one of the Organic Farms investigated by GBF please click here - credit for footage to ‘Abolish Salmon Farming’ 

Soil Association’s response

When contacted by the Green Britain Foundation, the Soil Association issued the following statements (abridged for clarity):

“It was previously possible for organic salmon farm sites to convert stock to organic. This meant non-organic salmon already present on the unit before the start of conversion would need to go through a minimum three-month conversion period before any products could be sold as organic.

Treatments the fish received prior to conversion could not be taken into account.

We recognised this was a weakness in the organic standards and in July 2024 introduced a new standard prohibiting this practice.”

The Association confirmed that Mowi’s Soay site was withdrawn from organic certification on 29 October 2024, and that a limited number of fish produced under the old conversion standard remain in circulation, though they expect these products to disappear from shelves by winter 2024/25.

They maintain that all products carrying the organic logo “met the standards in place at the time of production.”

Consumer implications

• Health risks: Shoppers have been paying premium prices for salmon exposed to toxic chemicals and antibiotics under the “organic” label.

• Erosion of trust: The Soil Association’s admission exposes major gaps in transparency within the certification system.

• Environmental harm: These chemicals cause widespread damage to marine ecosystems, contradicting the principles of sustainable aquaculture.

Call for action

The Green Britain Foundation urges:

1. Consumers to exercise caution when purchasing so-called “organic” salmon.

2. Regulators to strengthen enforcement of organic standards.

3. Certifiers to implement greater transparency over farm-level treatment data.

4. Supermarkets to ensure that all organic-labelled products genuinely meet the updated 2024 standards.

This investigation highlights the urgent need for robust oversight and truth in labelling, ensuring that products sold as “organic” meet the ethical, environmental, and safety expectations of consumers.