Arsenic is a chemical element found in water, air, food and soil as a naturally occurring substance or due to contamination from human activity.
Arsenic occurs in organic and inorganic forms. The organic forms are of relatively low toxicity while the inorganic forms present a greater hazard. Because both appear naturally in soil and ground water, small amounts are unavoidably found in some food and drinks.
Arsenic compounds were more widely used in the past, for example in pesticides and veterinary drugs, but there are currently no registered uses for inorganic arsenic for food crops or for animal production in Australia and New Zealand. Inorganic arsenic is registered for use in timber preservatives and for controlling termites in timber.
Arsenic in seaweed and other foods
Some seafood and seaweed products can contain high levels of inorganic arsenic. These products include hijiki seaweed, a brown seaweed that is black in appearance and usually comes in shredded form. It is mostly added to other foods such as rice and soups. Hijiki seaweed is not used in sushi products nor as a seaweed wrap.
There are limits in the Food Standards Code for inorganic arsenic in certain foods. A limit of 1mg/kg applies to seaweed and molluscs, while for fish and crustacea inorganic arsenic is not allowed above a level of 2mg/kg.
There is also a limit in the Code for total arsenic of 1mg/kg for cereals such as rice and 0.5 mg/kg for salt.
These limits, which are set at levels consistent with protecting public health and safety and which are reasonably achievable, cover the major foods that are likely to contribute to arsenic exposure.
Imported hijiki seaweed is also tested for arsenic (by the Department of Agriculture) as it is considered a 'risk food'. Due to this classification, 100 per cent of hijiki seaweed consignments are initially inspected and tested for inorganic arsenic. Hijiki consignments that do not meet the limit for arsenic in the Code cannot be imported.
In general, arsenic is present in the vast majority of foods, at extremely low levels. While there are measures in place to protect people from high levels of arsenic, people who regularly consume high levels of hijiki seaweed, along with other foods that may contain arsenic, may have a higher potential health risk from exposure than the general population. FSANZ advises people to eat a mixed diet with a variety of foods to minimize any risks associated with eating a more limited diet.
If you are concerned about your exposure to arsenic, consult a health professional, such as a doctor.
FSANZ regularly monitors levels of contaminants in a range of foods through the Australian Total Diet Study (ATDS) and targeted surveys.
Both the 23rd and 25th ATDS included testing of total and inorganic arsenic in a range of foods. A similar survey is carried out in New Zealand.
In addition, several targeted surveys that have been undertaken by FSANZ in recent years relate to the monitoring of inorganic arsenic in seaweed (2013), total and inorganic arsenic in apple and pear juice (2014), and tin, lead and arsenic in tinned fruits (2015).
Most recently, FSANZ provided input into an analytical survey commissioned by the New Zealand Ministry for Primary Industries and conducted by the laboratories at the Institute of Environmental Science and Research Ltd. The survey looked at inorganic arsenic in 200 rice and rice-based food products from Australia and New Zealand, including foods for infants and young children. Where present, inorganic arsenic levels in rice and rice-based products were low compared to levels reported from comparable studies overseas.
FSANZ will continue to monitor and publish our findings on dietary levels of arsenic, and update our advice if necessary.
Department of Agriculture and Water Resources imported food notice for 'risk foods'
FSANZ surveillance reports
 Ashmore E, Molyneux S, Watson S, Miles G & Pearson A (2019) Inorganic arsenic in rice and rice products in New Zealand and Australia. Food Additives and Contaminants Part B, DOI: 10.1080/19393210.2019.1651403.