What baking soda does not contain heavy metals? Fact vs. Fiction

December 17, 2025 •

4 min read

While many worry about aluminum in baking soda, research shows pure sodium bicarbonate does not inherently contain it, a misconception that has persisted for years. However, the real concern for consumers seeking maximum purity lies in potential trace amounts of other heavy metals and the crucial differences between product grades.

Quick Summary

Pure baking soda does not contain heavy metals, but manufacturing processes can introduce trace contamination. The main concern is distinguishing between high-purity food-grade products and lower-quality, industrial-grade versions.

Key Points

Aluminum-Free by Nature: Pure baking soda (sodium bicarbonate) does not contain aluminum, a misconception arising from confusion with some baking powders.
Purity Depends on Grade: To avoid potential heavy metal contamination, always choose food-grade or USP-grade baking soda, as industrial grades have less strict regulations.
Sourcing Matters: Naturally mined baking soda (from trona) is processed with water and is often preferred by those seeking minimal processing, though synthetic production also yields pure product.
Trace Amounts are Possible: Even food-grade baking soda can contain trace, environmentally sourced heavy metals, but these are typically within safety limits set by regulatory bodies.
Check for Transparency: For highest confidence, choose brands that publicly disclose their heavy metal testing results and purification methods.
Food-Grade is Safe: The baking soda found in grocery stores for consumption (food-grade) is purified to strict standards and considered safe for use.

The Core Misconception: The Aluminum Myth

One of the most widespread myths about baking soda is that it contains aluminum. This confusion stems from its resemblance and use alongside baking powder, a product that can sometimes use aluminum-based compounds as an acidic agent. Baking soda, which is 100% sodium bicarbonate, is a simple alkali salt and does not naturally contain aluminum. Reputable manufacturers, including Arm & Hammer, have consistently confirmed that their baking soda contains zero added aluminum. Any label proclaiming a product is 'aluminum-free' is often a marketing strategy to address this common customer concern, not an indication of a superior, less-common product type.

Natural vs. Synthetic Sourcing

The sodium bicarbonate used for baking soda can come from two primary sources: natural mineral deposits or a synthetic chemical process. Natural baking soda is sourced from underground mineral ore called nahcolite, which is a naturally occurring form of sodium bicarbonate. It is mined and purified using a simple water process, which some consumers prefer due to its minimal processing. In contrast, synthetic sodium bicarbonate is produced in a lab, typically through the Solvay process, which combines salt, ammonia, and carbon dioxide. While both methods can yield pure sodium bicarbonate, the sourcing and processing can impact the final product's trace mineral profile. Products specifically labeled as 'natural' or 'mined from the earth' are often preferred by those with concerns about synthetic chemical exposure.

The Importance of Purity Grades

Not all baking soda is created equal, and the grade of the product is the most important factor in determining potential heavy metal contamination. The key distinction is between food-grade (often referred to as USP grade) and industrial-grade sodium bicarbonate.

Food-Grade (USP): This stands for United States Pharmacopeia and signifies that the product meets strict purity standards for human consumption and medicinal use. USP grade baking soda is tested for elemental impurities, including heavy metals like lead, mercury, cadmium, and arsenic, to ensure levels are well below government-regulated safety limits. Brands that advertise themselves as USP grade or organic-use certified are held to these higher benchmarks.
Industrial-Grade: This type is used for cleaning, animal feed, or other non-food applications. Regulations are less stringent, meaning it can contain higher levels of impurities and contaminants, including heavy metals. Quora expert Martin J. Pitt noted that industrial-grade can contain significantly higher levels of lead and copper compared to food-grade.

To ensure you are using a product with the lowest possible heavy metal content, always choose a baking soda that is explicitly labeled 'Food-Grade' or 'USP Grade.'

Heavy Metal Testing and Trace Contamination

Concerns about heavy metals are not entirely unfounded, but they are often misunderstood. The presence of heavy metals in any food product is a risk due to environmental factors and manufacturing processes. Even food-grade baking soda can contain minuscule, trace amounts of heavy metals, but these are typically within safe and regulated limits. The Environmental Working Group (EWG) once tested baking soda brands and found trace amounts of lead, mercury, and arsenic, though these levels were below the FDA's safety limits. However, some holistic health proponents argue that any level of heavy metal contamination is undesirable. For this reason, selecting a product with transparent testing is crucial. For example, Church & Dwight Co., Inc., the maker of Arm & Hammer, publicly provides elemental impurity test data for their USP-grade sodium bicarbonate on their performance products website, detailing levels for cadmium, lead, arsenic, and mercury.

How to Choose the Purest Baking Soda

For those seeking the purest option, follow these steps:

Choose USP Grade: Prioritize products explicitly labeled as 'USP Grade' to ensure they meet the highest standards for consumption.
Research the Source: Brands that mine their baking soda from natural deposits, like those in Colorado, and use a simple water process may offer higher purity.
Seek Third-Party Certification: Look for brands certified by third-party organizations like the Organic Materials Review Institute (OMRI) for organic use, which ensures a chemical-free process.
Check for Transparency: Look for companies that provide test results for heavy metals and other contaminants, such as the information provided by Arm & Hammer on their performance products site.

Comparison of Baking Soda Grades and Heavy Metal Risk


Feature	Food-Grade (USP) Baking Soda	Industrial-Grade Baking Soda	Naturally Mined Baking Soda	The Aluminum Myth
Purity Standards	High. Must adhere to strict USP standards for medicinal and edible use.	Lower. Not regulated for consumption; can contain higher impurity levels.	High. Often minimally processed using a water-based method.	Irrelevant. Pure sodium bicarbonate naturally contains no aluminum.
Heavy Metal Content	Trace amounts are typically present but remain well below safety limits.	Can contain significantly higher levels of heavy metals like lead and copper.	May contain naturally occurring trace minerals, but often very minimal.	The confusion is with baking powder, which can contain aluminum compounds.
Best for...	Cooking, baking, medicinal purposes, and personal care.	Household cleaning, industrial applications, animal feed.	Any use requiring high purity, often preferred by those who prioritize natural ingredients.	Avoids a nonexistent problem and clarifies the distinction with baking powder.

Conclusion: Selecting for Purity

For consumers concerned about heavy metals, the answer lies in understanding product sourcing and purity standards rather than a blanket concern over all baking soda. Pure sodium bicarbonate, by definition, does not contain aluminum, and selecting food-grade (USP) products significantly minimizes the risk of consuming heavy metal contaminants. Always read product labels to confirm the grade, and for maximum peace of mind, opt for brands that provide information about their sourcing and testing procedures. Your best defense is informed purchasing.

For more detailed information on specific heavy metal test results for Arm & Hammer's USP sodium bicarbonate, visit the official ARM & HAMMER™ Performance Products site.

Frequently Asked Questions

Arm & Hammer states that their USP-grade baking soda is tested for heavy metals and that levels are well within safety standards. The product is 100% sodium bicarbonate and does not contain added aluminum.

Yes, pure baking soda is sodium bicarbonate and does not contain aluminum. The myth likely originated from confusion with baking powder, which sometimes uses aluminum compounds.

The main difference is purity standards. Food-grade (USP) baking soda is purified and tested to ensure it is safe for consumption, while industrial-grade has fewer regulations and may contain higher levels of impurities and heavy metals.

You can't test for heavy metal content at home without laboratory equipment. However, a simple baking soda test can check if your cookware is leaching metals by boiling water with baking soda and tasting for a metallic flavor.

Brands that source naturally mined sodium bicarbonate (from trona), process it with a simple water method, and offer USP-grade certification are often considered among the purest. Look for brands with third-party verification, like OMRI certified for organic use.

Trace amounts can be introduced from the environment during mining or processing. All food products have a risk of environmental contaminants, but food-grade products are regulated to ensure levels are safe for consumption.

Natural baking soda is processed using a simple water method. Synthetic sodium bicarbonate is produced using the chemical Solvay process. Both yield pure products, but naturally sourced is preferred by some seeking to avoid chemicals.

For most culinary and household applications, there is no noticeable difference in performance between synthetically produced and naturally mined baking soda. The primary difference is the perception of purity related to sourcing.