Skip to main content

Seaweed and fish: inorganic arsenic

From January - May 2010, the NSW Food Authority tested 48 seaweed and 10 fish product samples from NSW retail outlets.

All samples were tested for total and inorganic arsenic and compared against regulatory limits for arsenic, set out in Standard 1.4.1 - ‘Contaminants and Natural Toxicants’ (pdf, 35KB) of the Australian New Zealand Food Standards Code.

Arsenic can be present in food in many different forms - either organic or inorganic.

It is a naturally occurring element which can be introduced into food from natural sources and as a result of human activities.

Food is a significant source of arsenic intake.

Most of the arsenic in the diet is present in an organic form, which does not present a hazard. Toxic inorganic arsenic in food typically makes up 1-3% of the total arsenic content. This can present a health hazard if it exceeds set regulatory limits.

Previous tests for total arsenic have identified high levels in certain fish species. There is little data available in regards to the level of inorganic arsenic in seaweed and fish in Australia.

Adverse effects in humans reported to be associated with long term ingestion of inorganic arsenic include skin lesions, cancer, developmental toxicity, neurotoxicity, cardiovascular diseases, abnormal glucose metabolism, and diabetes. Excess levels have been linked to reduced birth weight in babies.


98.3% of samples tested contained inorganic arsenic below the regulatory limit.

One dried seaweed product exceeded the regulatory limit. The product has been withdrawn from sale and is no longer imported to Australia.

Inorganic arsenic in seaweed and certain fish October 2010, (pdf 154KB, 7pp)

Table of contents
Executive summary
1. Introduction
2. Methods of analysis
3. Results and discussion
4. Conclusion
5. References
6. Appendix: Results of testing