Executive summary


Interest in using seaweed as food is growing in Nordic countries and in other countries in Europe.
Seaweed is the biggest aquaculture product in the world, yet there are still no international standards on food safety, such as Codex standards or guidelines. The EU is also lacking specific legislation on food safety for seaweed.
In Europe there is limited experience of using seaweed, and little is known about potential risks and benefits to human health when it is consumed. Risk management of foodstuffs based on seaweed is therefore a challenge. Guidance is needed for both producers and public agencies to ensure food safety, to facilitate uniform control and trade, and to support innovation and growth in this sector.
A common Nordic approach is called for, in view of the differences, both globally and within Europe, in tradition, food culture, production methods, seawater quality, and types of seaweed species used. Nordic species and production conditions should be considered in future development of legislation in EU and also of global standards.
The scope of this report covers food safety aspects of seaweed used as food, with the main focus on currently identified chemical and microbiological food hazards. Aspects outside the scope of this study are refined industry products such as alginate and carrageen, potential health benefits of eating seaweed, legislation on organic production, and self-picking of seaweed by consumers.

Status in the Nordic countries and identified food hazards

Existing production and risk management of seaweed used as food in Denmark, the Faroe Islands, Iceland, Norway, and Sweden, are described. Nordic seaweed species currently relevant for food are listed, including their respective novel food status, as well as ranges of their heavy metals and iodine content.
Based on current knowledge, the most crucial food hazards relevant for seaweed harvested in the Nordic countries are iodine, cadmium, and inorganic arsenic. Iodine is an essential micronutrient, but both insufficient and excessive intake may pose health problems. Some food products based on seaweed contain very high levels of iodine, which is why iodine is classified as a hazard in this context.
Other important food hazards to be considered are lead and mercury, Bacillus spp in heat-treated products, kainic acid in dulse, and allergens. Several other possible hazards are also discussed in this report.
There is currently a shortage of data on food hazards in seaweed, and this should be kept in mind. Knowledge concerning food safety in seaweed is increasing, but more data is needed to ensure proper risk assessments. The type, level and ranking of food hazards in seaweed in Nordic countries may change in the future as research produces new data, and conditions may be altered by climate change, such as increased sea temperature. New seaweed species may also be introduced into Nordic waters.

Variations in levels of heavy metals and iodine within and between seaweed species

The levels of heavy metals and iodine vary greatly between and within species, and can be affected by age, growing conditions, and processing methods.
The data on iodine, cadmium, inorganic arsenic, lead, and mercury in seaweed from Denmark, the Faroe Islands, Iceland, Norway, and Sweden confirm great variabilities both between and within species. Differences between species seem to be quite similar in the Nordic countries.
Despite the shortage of data available for this report, there is enough to at least give an indication of which species present the greatest challenges in terms of heavy metals and iodine in Nordic seaweed production.
In general, the brown algae have the highest iodine content, with the highest levels found in the species sugar kelp, winged kelp, oarweed, and tangle. Red and green algae species have lower levels of iodine than the brown algae, except for the red algae wrack siphon weed. Oarweed can have exceptionally high levels of inorganic arsenic, while cadmium levels are highest in several brown and red algae.

Legislation and future considerations

The current status of EU legislation regarding food safety aspects is discussed. Legislation on foodstuffs other than seaweed is presented to illustrate existing legislation on food safety hazards. It is also emphasised that legislation applying to a specific foodstuff is not directly applicable for other types of foodstuffs.
Regardless of the current limitations of legislation specific to seaweed, the general requirements in EU food legislation apply for all types of foodstuffs, including seaweed.
Food business operators are responsible for ensuring that foodstuffs placed on the market must be safe to consume.
Compared to other organisms used as food, such as terrestrial plants like vegetables, fruits and mushrooms, seaweeds have different properties and growth environment and might also differ in terms of bioavailability of the food hazards. In addition, seaweed may be consumed in different amounts and patterns than other foodstuffs. The great differences between seaweed species and the effect of age, growing conditions, and processing methods on the levels of food hazards should also be considered in future legislation.
The authors of this report strongly recommend development of a harmonised legislation on food safety in seaweed. In such legislation, seaweed should be classified as a specific group of foodstuffs, with subgroups for different seaweed species.
In the near future, the EU Commission is expected to evaluate risk management options for heavy metals and iodine in seaweed. This work will be welcomed by the food authorities in Denmark, the Faroe Islands, Iceland, Norway, and Sweden.
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