Total vs Inorganic Arsenic in Baby Food: Why Fish Meals Can Test High

The short answer

"Total arsenic" counts every chemical form of arsenic in a food; "inorganic arsenic" is the form FDA calls more dangerous and the one its baby-food action levels target [1][2]. Fish-containing baby meals can show high total arsenic while carrying very little inorganic arsenic: in a 2026 French study, inorganic arsenic was under 1% of the total in the highest fish samples [4][5]. So the form matters as much as the number.

This is general information, not medical advice. Talk to your pediatrician if you are worried about what your child eats.

What is the difference between total and inorganic arsenic?

Total arsenic is the sum of all arsenic in a sample, whatever chemical form it is in; inorganic arsenic is one part of that total. FDA says current research indicates inorganic arsenic is more dangerous than organic arsenic and its health effects are more severe [1]. "Organic" here is chemistry, not farming: organic arsenic compounds contain carbon and have nothing to do with organic produce [1].

FDA also notes that two organic forms found in some foods, dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA), may be a health concern, and it is monitoring research on them [1].

Form of arsenic	Type	What the sources say
Arsenite and arsenate	Inorganic	The forms FDA considers more dangerous; target of FDA action levels for infant rice cereal and apple juice [1][2][3]
DMA and MMA	Organic	May be a health concern; FDA is monitoring emerging research [1]
Arsenobetaine and other organoarsenic compounds	Organic	Common in marine fish; explain why total arsenic overstates the toxicologically relevant fraction in fish meals [5]

Why can fish-based baby meals test high for total arsenic?

Fish meals can test high for total arsenic because seafood carries organic arsenic compounds such as arsenobetaine, not because they are loaded with inorganic arsenic. A study published in 2026 in Food Additives & Contaminants: Part B measured 28 elements in 97 baby foods bought in French supermarkets in 2024, including 18 vegetable-and-fish meals [4][5].

Arsenic was low in fruit, vegetable and meat products and infant cereals, but significantly higher in the vegetable-and-fish meals: median total arsenic 0.0663 mg/kg, maximum 0.875 mg/kg [5]. In the five samples with the highest total arsenic, inorganic arsenic was below 0.003 mg/kg, and the inorganic share was less than 1% of total arsenic [5]. The researchers link this to arsenobetaine and other organoarsenic compounds common in marine fish, and warn that total arsenic alone "would substantially overestimate" the relevant fraction in these samples [5].

Two limits are worth knowing. Inorganic arsenic was measured in only five selected samples, and the products were sold in France, not the US [5]. The regulated toxic elements tested, including lead and cadmium, were within European maximum levels [5].

Which form of arsenic does FDA limit in baby food?

FDA's arsenic action levels for foods children commonly eat are set for inorganic arsenic. FDA has a final action level for inorganic arsenic in infant rice cereals (August 2020) and in apple juice (June 2023) [1][2][3]. Consumer Reports lists the infant rice cereal action level as 100 ng/g, which is 100 ppb [6]. For more on rice cereal, see our infant rice cereal arsenic guide; for juice, see lead and arsenic in fruit juice.

The European Union also sets its contaminant maximum levels for arsenic as inorganic arsenic [7]. Action levels are guidance, not regulations: FDA says its guidance documents do not establish legally enforceable responsibilities [2].

How do labs tell total and inorganic arsenic apart?

Labs usually measure total arsenic first, then run a second "speciation" test that separates the chemical forms. FDA says it tests foods for total arsenic and, if needed, tests samples further to determine the levels of organic and inorganic arsenic species [1].

Consumer Reports followed the same two-step approach in its 2026 baby-food project. Total arsenic was measured by ICP mass spectrometry, and any sample with arsenic above the method detection limit was analyzed for the inorganic species arsenate and arsenite plus organic species including MMA and DMA [6]. CR detected inorganic arsenic in 37 of the 48 products it tested [8]. Our rice snacks explainer shows CR's inorganic arsenic results by product.

How should parents read an arsenic result on a lab report or brand disclosure?

Check which form is reported before comparing numbers. A practical checklist:

1. Look for the word "inorganic." A "total arsenic" figure is not directly comparable with FDA's inorganic arsenic action levels [1][2].
2. Check the units. ppb, µg/kg and ng/g are the same unit; mg/kg is 1,000 times larger (0.003 mg/kg = 3 ppb).
3. Note the food type. A high total arsenic number in a fish meal may be mostly organic arsenic [5]; in rice-based foods, inorganic arsenic is the usual concern because rice absorbs arsenic more readily than other crops [9].
4. Remember detection is not danger. FDA says testing results that detect arsenic do not necessarily mean a food should be avoided [1].

Our rankings score brands on whether they publish lab results at all; we do not convert total arsenic into inorganic arsenic or invent missing numbers.

Should I avoid fish-based baby foods because of arsenic?

No. The sources do not support avoiding fish meals because of total arsenic alone. FDA advises a variety of nutrient-dense foods to limit exposure to any one contaminant [1], and its fish advice for children says fish provide key nutrients that support brain development, plus iron and zinc for the immune system [10]. Mercury is a separate issue: use FDA's fish advice to choose lower-mercury fish [10].

FAQ

Is organic arsenic the same as arsenic in organic food?

No. "Organic arsenic" means arsenic bound to carbon, a chemistry term. It is not related to organic farming [1].

Why does FDA test total arsenic first?

FDA says it tests foods for total arsenic and, if needed, runs further tests to find how much is organic and how much is inorganic [1]. Consumer Reports used the same two-step approach in 2026 [6].

Is a high total arsenic result in a fish puree dangerous?

Not necessarily. In the 2026 French study, inorganic arsenic was less than 1% of total arsenic in the highest fish samples [5]. Ask the brand for an inorganic arsenic result if only total arsenic is shown.

Does cooking reduce inorganic arsenic?

For rice, FDA says cooking it in excess water like pasta can reduce 40 to 60 percent of inorganic arsenic, depending on rice type [9]. This applies to rice you cook, not to ready-made baby food.

Where does inorganic arsenic in baby food come from?

Arsenic in soil and water can be taken up by plants and enter food, and it can also enter during processing, for example through contaminated water [1].

References

1. U.S. FDA, Arsenic in Food.
2. U.S. FDA, Guidance for Industry: Action Level for Inorganic Arsenic in Rice Cereals for Infants (August 2020).
3. U.S. FDA, Guidance for Industry: Action Level for Inorganic Arsenic in Apple Juice (June 2023).
4. Leufroy A., Elements in baby foods from the French market and associate health risks, Food Additives & Contaminants: Part B (2026).
5. News-Medical, Does choosing organic baby food change its mineral content? (November 2, 2026).
6. Consumer Reports, Contaminants in Baby Food: Test Methodology (September 2026, PDF).
7. EUR-Lex, Commission Regulation (EU) 2023/915 on maximum levels for certain contaminants in food.
8. Consumer Reports, We Tested 48 Baby Foods for Heavy Metals and Microplastics (September 17, 2026).
9. U.S. FDA, What You Can Do to Limit Exposure to Arsenic.
10. U.S. FDA, Advice about Eating Fish.