Heavy metals in food databaseRice, grains and beansChecked 2026.10.03
Soybeans: cadmium, arsenic, lead
In a MAFF survey (2011–13 crops, 1,800 samples), cadmium in domestic dried soybeans averaged 0.11 and peaked at 0.87 mg/kg. About 11% of the cadmium taken in from agricultural products is estimated to come from soybeans. Total arsenic and lead were mostly below the limit of quantification.
Levels measured in Japanese government surveys and studies
| Metal | Form / state | Mean | Range / max | Samples | Survey |
|---|---|---|---|---|---|
| Cadmium | Total cadmium, dried soybeans (domestic) | 0.11 (median 0.10) | max 0.87 | 1,800 samples | MAFF, 2011–13 crops |
| Arsenic | Total arsenic, soybeans (domestic) | 0.008 | max 0.04 | 300 samples (93% below the limit of quantification) | MAFF, fiscal 2003–05 |
| Lead | Total lead, soybeans | 0.00–0.02 | max 0.06 | 300 samples (265 below the limit of quantification) | MAFF, fiscal 2003–05 |
Units are mg/kg (= ppm). A range such as “0.00–0.02” runs from the mean with samples below the limit of quantification counted as 0 to the mean with them counted at the limit of quantification. Arsenic is total arsenic.
Limits (Japan, international, EU)
| Set by | Limit | Note |
|---|---|---|
| Japan (Food Sanitation Act) | No standard for cadmium, arsenic, or lead | The cadmium standard covers only rice and mineral waters |
| Codex (international standards) | Cadmium: dried soybeans are excluded from the pulses limit (0.1) / lead, dried pulses 0.1 | — |
| EU (Regulation 2023/915) | Cadmium, soybeans and peanuts 0.20 (pulses 0.040) / lead, dried pulses 0.20 | — |
Good to know
- Cadmium in domestic soybeans is higher than in rice (average 0.04) or wheat (0.05), with an average of 0.11, a median of 0.10, a 95th percentile of 0.23, and a maximum of 0.87 mg/kg. As a reference using another country’s yardstick, about 9.6% of samples were at a level that would exceed the EU’s limit for soybeans of 0.20 (Japan and Codex have no standard).
- MAFF’s estimate (2016) is that about 46% of the cadmium taken in from agricultural products comes from rice, 17% from wheat, and 11% from soybeans. The contribution to intake is determined not only by concentration but also by how much is eaten.
- In processing, the share of cadmium that moves into the product differs (MAFF’s material). 61–66% of the soybeans’ cadmium goes into tofu, 83–84% into miso, and 43–53% into soy sauce, and the rest is divided among okara and tofu whey (“yu”) and other byproducts.
- Total arsenic averages 0.008 mg/kg with 93% below the limit of quantification, and for lead 265 of 300 samples were below the limit of quantification. These values are an order of magnitude lower than for rice or seaweed.
- Japan’s cadmium standard covers only rice and mineral waters. The Consumer Affairs Agency says that for foods other than rice, intake is small and setting a standard would have little reducing effect, so it responds with measures at the production stage and surveys of actual levels.
- What was surveyed is domestic dried soybeans. No public survey values were found for imported soybeans or for processed products such as natto and soy milk.
Related explainers
Pages for each metal
Sources
- MAFF, “Survey of cadmium in domestic agricultural products (fiscal 2009–14)”
- MAFF, cadmium survey data (attachment, agricultural products, Table 3.3)
- MAFF, changes in cadmium through processing (tofu, miso, soy sauce)
- MAFF, “Survey of arsenic contained in food”
- MAFF, “Survey of lead contained in agricultural products”
- Consumer Affairs Agency, “Q&A on cadmium in food”
- EU Regulation 2023/915 (maximum levels for contaminants in food)
Last checked 2026.10.03 (against the original government documents and papers, collected and cross-checked in Gemini Notebook).
Heavy metals occur naturally in soil and the sea, and every food contains small amounts. This page lists facts from government surveys, limits and assessments and from published papers; it does not judge any food as good or bad. Where there is official advice — such as on eating fish during pregnancy — follow it.