Cooking rice in a large volume of water and draining the excess is the single most effective home method for reducing arsenic, cutting inorganic arsenic by roughly 45% in some rice types. Rinsing alone does far less than most people assume, and soaking helps moderately under specific conditions. The details matter because arsenic removal depends on the type of rice, the ratio of water, the quality of your tap water, and whether you are willing to accept some loss of nutrients in exchange for lower arsenic levels.
Why Rice Contains Arsenic in the First Place
Rice is uniquely efficient at pulling arsenic from the soil. Paddy fields are flooded for much of the growing season, and waterlogged conditions convert arsenic in the soil into forms that dissolve easily into the water surrounding the roots. The rice plant then absorbs these dissolved arsenic compounds through the same channels it uses to take up silicon, a nutrient it needs in large quantities. Specifically, the silicic acid transporter in rice roots appears to play a key role in letting both inorganic arsenic and methylated forms like dimethylarsinic acid enter the plant.
Once inside the plant, arsenic travels upward and concentrates in the grain. The result is that rice tends to contain more arsenic than other cereal crops grown in the same soil. Two main chemical forms of arsenic end up in the grain: inorganic arsenic (the more toxic kind, which includes arsenite and arsenate) and organic arsenic, primarily dimethylarsinic acid. The ratio between these forms varies by where the rice was grown and what variety it is. U.S.-grown rice, for instance, tends to have a higher proportion of the organic form, while rice from parts of Asia and Europe often carries more inorganic arsenic.
Brown Rice Versus White Rice
If you eat brown rice for its nutritional benefits, this is a trade-off worth knowing about. The outer bran layer that makes brown rice more nutritious also concentrates arsenic. Brown rice consistently shows higher total arsenic and higher inorganic arsenic than white rice milled from the same grain.
Polishing rice, the process that strips the bran to produce white rice, removes a meaningful fraction of arsenic along with the fiber and minerals. One study on Japanese rice cultivars found that polishing alone reduced arsenic levels to roughly 80% of what was in the whole grain. That is not a dramatic drop, but it is a free reduction that happens before you even start cooking. For people who eat rice daily, switching from brown to white rice is one of the simplest ways to lower arsenic intake, though it comes at the cost of fiber, magnesium, and B vitamins.
What Rinsing Actually Does
Rinsing rice before cooking is deeply ingrained in many food cultures, and it does improve texture and remove surface starch. Its effect on arsenic, though, is modest at best. Research on the topic has found that rinsing has a minimal effect on the arsenic content of the cooked grain. One study testing basmati rice found that rinse-washing removed only about 10% of total and inorganic arsenic, and was even less effective for other rice types.
A Japanese study found slightly better results, with three washes reducing arsenic to about 71–84% of the original levels depending on the cultivar. Interestingly, the same study noted that “rinse-free” rice, which has its residual bran mechanically removed before packaging, performed similarly to rice that had been washed three times. So if you buy rinse-free rice, you are getting a comparable arsenic reduction without the washing step.
The bigger concern with rinsing is what else leaves with the wash water. Enriched white rice in many countries is coated with added iron, folate, thiamin, and niacin. Rinsing washes a significant portion of these added nutrients off the grain surface. If your rice is enriched and arsenic is a concern, the trade-off of rinsing is not especially favorable: you lose meaningful vitamins for a small arsenic reduction.
Soaking Before Cooking
Soaking rice overnight is sometimes recommended as an arsenic-reduction step, and the evidence suggests it helps, though the degree depends heavily on temperature and duration. At room temperature, soaking brown rice for extended periods reduced total arsenic by up to about 18% after 48 hours. That is a real reduction but not a dramatic one, and few people plan 48 hours ahead for a pot of rice.
Temperature makes a bigger difference. When brown rice was soaked in progressively warmer water, arsenic removal jumped sharply between 60°C and 70°C, with reductions reaching about 33–37% at the higher temperature. At those temperatures you are essentially doing a brief par-cook, which starts to break down the grain structure and release arsenic into the water. The practical challenge is that maintaining water at 70°C for an extended soak is not something most home kitchens are set up to do easily.
After soaking, you should always discard the soaking water and use fresh water for cooking. Otherwise you are just reintroducing the arsenic that leached out.
Cooking With Excess Water
Of all the approaches a home cook can realistically use, cooking rice in a large volume of water and then draining the excess is the most effective. Think of it as cooking rice the way you would cook pasta: boil it in far more water than it can absorb, then pour off the extra.
A study testing different cooking methods found that high-volume water cooking removed about 35% of total arsenic and 45% of inorganic arsenic from long-grain and basmati rice, compared to the raw grain. By contrast, cooking with the standard absorbed-water method, where you use just enough water for the rice to soak it all up, did not remove arsenic at all. Steaming reduced arsenic somewhat but not consistently across rice types.
The ratio matters. Research generally uses somewhere around 6:1 water to rice or higher to see meaningful reductions. A 1:1 or 2:1 ratio, the kind used in most rice cookers and many stovetop recipes, leaves the arsenic nowhere to go: whatever was in the grain stays in the grain, and whatever was in the water gets absorbed into the grain too.
Percolation Cooking
The most aggressive home-scale arsenic removal comes from percolation, where fresh water continuously passes through the rice rather than sitting in a pot with it. Researchers tested this by rigging up a system where boiling water flowed through rice in a manner similar to a coffee percolator. The results were striking: percolating cooking water removed about 59% of inorganic arsenic from polished rice and about 69% from wholegrain rice on average, with some individual samples losing over 80%.
A follow-up trial using an actual home coffee percolator achieved roughly 49% removal of inorganic arsenic across all samples tested, with one sample reaching 85% removal. The principle is straightforward: arsenic leaches out of the grain into the water, and instead of that water being reabsorbed, it is carried away and replaced by fresh water. The more water that passes through, the more arsenic leaves.
This same approach was tested on rice bran specifically, where up to 96% of inorganic arsenic was removed when bran was cooked in percolating water. That is an extreme case, since bran has a much higher surface-area-to-volume ratio than whole grains, but it illustrates how effective continuous water exchange can be.
The practical downside is that percolation cooking is not how most people prepare rice, and the texture of the finished product can differ from what you are used to. But if arsenic reduction is a priority, especially for someone eating rice multiple times a day, it is the most effective kitchen-scale technique available.
Your Tap Water Can Make Things Worse
Every arsenic-removal cooking method assumes you are using clean water. If your cooking water itself contains arsenic, you can actually increase the arsenic content of the cooked rice. This is not a hypothetical concern: in parts of South Asia, particularly the Indo-Gangetic Plain and regions of Bangladesh, groundwater arsenic levels are high enough that cooking rice in local well water adds more arsenic than the grain started with.
Research in the Indo-Gangetic Plain found that both soaked and cooked rice showed significantly higher arsenic when prepared with arsenic-contaminated water, regardless of the rice variety. The same rice prepared with arsenic-free water showed significant reductions. A study in Bangladesh found a clear linear relationship between the arsenic concentration in cooking water and the change in arsenic in the cooked rice. The more contaminated the water, the more arsenic the rice picked up during cooking.
This matters for the excess-water method especially: if you cook rice in a large volume of arsenic-laden water, you are essentially bathing the grain in a dilute arsenic solution. The grain absorbs water as it cooks, and the arsenic comes along for the ride. For anyone living in an area with known groundwater arsenic contamination, using filtered or tested water for rice cooking is not optional; it is the most important single step you can take.
Parboiled rice presents a related concern. Parboiling involves soaking and steaming paddy rice before milling, and if the water used in that industrial process is contaminated, the parboiled grain can end up with dramatically more arsenic than raw-milled rice. One study in a heavily affected zone of West Bengal found parboiled rice samples averaged about 186 micrograms per kilogram of arsenic, compared to 66 micrograms per kilogram in non-parboiled samples from the same area, representing an increase of over 200%.
The Nutrient Trade-Off
Arsenic leaves the grain dissolved in water, but so do vitamins and minerals. Any method that removes arsenic by washing it away in excess water also removes some of the nutrients you might be eating rice to get. Research on household cooking processes found that washing caused significant losses in B vitamins, minerals, and phytic acid, while soaking primarily decreased thiamin content. Cooking itself further reduced B vitamins, with high-pressure cooking causing the steepest losses.
A separate study specifically tracking iron and zinc found that cooking rice in a rice cooker without prior washing retained the highest concentrations of both minerals, in both fortified and non-fortified varieties. Fortified rice was especially vulnerable to nutrient loss, since the added micronutrients sit on the grain surface and wash off more easily than nutrients bound within the grain structure.
For most people in developed countries who eat a varied diet, losing some B vitamins and iron from rice is not a nutritional crisis. But for populations where rice provides the majority of daily calories and micronutrients, the trade-off is real. The ideal approach depends on context: someone eating rice once a day alongside meat and vegetables can afford the nutrient cost of excess-water cooking. Someone subsisting primarily on rice may need to balance arsenic reduction against the risk of micronutrient deficiency.
Infants and Young Children
Infants are more vulnerable to arsenic exposure than adults, both because they are smaller and because rice cereal is a common first food. The U.S. Food and Drug Administration established an action level of 100 parts per billion for inorganic arsenic in infant rice cereals. When the FDA tested infant rice cereals from 2018, about 76% of samples met that 100 ppb threshold, up from 47% in 2014 testing, suggesting that manufacturers have been reformulating their products.
Many pediatric nutrition guidelines now suggest diversifying infant cereals beyond rice. Oat, barley, and multigrain cereals tend to have lower arsenic levels, and rotating among them reduces cumulative exposure. For parents who do serve rice cereal, choosing products explicitly tested for arsenic content and preparing rice-based foods with excess water where possible are reasonable precautions.
What Your Body Actually Absorbs
Not all the arsenic in a serving of cooked rice ends up in your bloodstream. Digestion studies using simulated gastrointestinal conditions have found that the bioaccessibility of arsenic in cooked rice, meaning the fraction that dissolves and becomes available for absorption during digestion, ranges from about 38–57% in the small intestine, with slightly higher values during small-intestine digestion compared to the colon phase. Other work using cell-culture models of the intestinal lining has found that bioaccessibility of inorganic arsenic can be much higher, reaching 63–99% after simulated digestion, though only a smaller fraction, roughly 4–18%, was actually taken up by the intestinal cells.
These numbers suggest that total arsenic content in rice overestimates what you actually absorb, but not by enough to be reassuring on its own. Even at the lower end of bioaccessibility estimates, chronic daily exposure from rice adds up, particularly for heavy rice consumers. The health concern is not acute poisoning from a single meal but cumulative exposure over years. Epidemiologic reviews have found that higher rice consumption, particularly in populations also exposed to arsenic through drinking water, is associated with increased risk of skin lesions, certain cancers, and cardiovascular disease.
A Practical Ranking of Home Methods
If you want a clear hierarchy of what to do in your kitchen, here is how the methods stack up based on the research:
- Percolation cooking: The most effective approach, removing roughly 50–70% of inorganic arsenic on average, with some samples exceeding 80%. Requires a setup that allows fresh water to flow through the rice continuously.
- Excess-water cooking: The most practical high-impact method. Boil rice in a 6:1 or higher water-to-rice ratio, drain the excess. Removes about 35–45% of arsenic from susceptible rice types.
- Soaking in warm water: Helpful as a pre-step, especially at temperatures around 70°C, where reductions of 33–37% in total arsenic have been observed. Always discard soaking water.
- Rinsing: Removes about 10–30% of arsenic depending on the rice type and how many washes you do. Better than nothing, but not a substitute for excess-water cooking.
- Standard absorbed-water cooking: Does not remove arsenic. Whatever is in the grain and the water ends up on your plate.
Combining methods, such as rinsing, then soaking, then cooking in excess water, stacks reductions. No single study has tested the full combination rigorously, but the mechanisms are additive: each step gives arsenic another opportunity to leach into water that gets discarded.
Choosing Lower-Arsenic Rice
Your choice of rice variety and origin matters as much as how you cook it. Basmati rice, particularly from India and Pakistan, and jasmine rice from Thailand tend to test lower in inorganic arsenic than rice grown in the south-central United States, where former cotton fields treated with arsenic-based pesticides decades ago still carry residual contamination in the soil. White rice contains less arsenic than brown rice of the same variety. And sushi rice, which is typically polished and rinsed extensively before use, arrives at the table with lower arsenic than most long-grain American varieties.
If you eat rice several times a week, rotating between rice and other grains like quinoa, millet, or bulgur is a simple way to reduce cumulative arsenic exposure without giving up rice entirely. For occasional rice eaters, the arsenic content of a few servings per week is unlikely to pose a meaningful health risk on its own, and elaborate cooking procedures are more about peace of mind than measurable health benefit.
What Is Happening Before Rice Reaches You
Researchers are also working on the problem at the agricultural end, long before rice reaches your kitchen. Strategies include adding soil amendments like silicon, selenium, and sulfur to paddy fields, which can compete with arsenic for uptake through the plant’s root transporters. Water management techniques, such as alternating between wet and dry conditions in the field rather than keeping paddies continuously flooded, reduce the amount of dissolved arsenic available to the plant.
One recent approach combined zero-valent iron mixed with limestone as a soil amendment alongside alternate wetting and drying water management. The iron formed chemical compounds that trapped arsenic in the soil, preventing it from entering the rice plant. These field-level interventions are promising but not yet widely adopted, and their benefits take time to scale. For now, the kitchen remains the last line of defense for the individual consumer, and the excess-water method remains the most accessible tool available.