Center for Research on Ingredient Safety

Updated: June 6, 2024

What is seltzer water?

Traditionally, seltzer water is carbonated water that does not contain sodium. Carbonated water is water that contains carbon dioxide gas that gives seltzer water its distinct bubbly feature.

What’s the difference between seltzer, sparkling mineral water, and club soda?

Seltzer water is carbonated water that doesn’t contain sodium.

Sparkling mineral water is typically sourced from a natural spring and will often contain naturally occurring minerals like sodium, calcium, magnesium, etc. Carbonation may occur naturally, or manufacturers may add carbonation.

Club soda is a type of water manufacturers carbonate and has additional ingredients including sodium bicarbonate, sodium citrate, potassium sulfate, and disodium phosphate.

What is flavored seltzer water?

Flavored seltzer water is carbonated water containing flavor ingredients that provide a specific flavor (e.g., mixed berry, lemon, etc.), typically without sodium, calories, or sugar.

How is seltzer water flavored?

As we’ve discussed in prior blogs posts (1,2), food scientists called flavorists use naturally and artificially derived ingredients to create the desired flavors.

Natural Flavor: Flavorists create natural flavors by using ingredients from natural sources such as essential oils, extracts, etc., that are derived from spices, fruits, vegetables, barks, and other natural sources. You can read the full definition of natural flavor on the U.S. FDA’s website.

Artificial Flavor: Flavorists create artificial or synthetic flavorings from chemical sources rather than natural sources.

How is seltzer water flavored without adding calories?

Flavor ingredients can be potent, so flavorists do not need to add a large quantity of flavor ingredients to seltzer water to get the desired taste. Meaning, you can get the wanted taste without impacting the nutritional profile because the flavor ingredient addition is small compared to the quantity of water.

Why do some seltzer or sparkling waters contain citric acid?

Citric acid can serve more than one purpose, it can impart a sour flavor we associate with citric fruits like lemons and limes. It can also serve as a preservative ingredient to help prevent the growth of undesirable organisms, such as bacteria.

Can water be certified organic?

No. The U.S. Department of Agriculture (USDA) certifies organic agricultural products. Water, including plain seltzer water, cannot be labeled as organic under their guidelines.

What is the difference between organic and traditional flavored seltzer water?

The flavor ingredients used to flavor seltzer waters can be derived from USDA-certified organic natural flavor sources.

Traditionally flavored seltzer waters may use naturally or artificially derived ingredients.    

What is the difference between non-GMO and traditional flavored seltzer water?

Genetically modified organisms (GMO) may include crops that scientists have genetically modified to grow better in specific situations. Non-GMO flavored seltzer water means the flavor ingredients used to flavor the seltzer water do not come from GMO crops.  

Can too much seltzer water be harmful?

As we’ve discussed, too much water, in general, can be harmful. The same goes for seltzer water.

Additionally, there is a potential to damage our tooth enamel due to seltzer water’s increased acidity. However, it’s minimal and far less harmful than tooth enamel damage from sugary soda pops (1,2,3).

As with all things in life, moderation is key.

Do seltzer waters contain PFAS/PFOS contaminants?

Some seltzer waters may contain trace levels of PFAS/PFOS contaminates that are well below the safe consumption threshold established by the U.S. EPA, even for vulnerable populations.

Seltzer waters with trace levels of PFAS/PFOS are safe to drink. Remember, the dose makes the poison.

What else should I keep in mind?

We’ve mentioned this earlier, but it’s important to note that flavor ingredients added to flavored seltzer waters are added in very small amounts. Marketing labels can be powerful when influencing us to buy a specific product.

Remember that organic, non-GMO, gluten-free flavored seltzer water will most likely have the same nutritional profile as traditionally flavored seltzer water.

The good news.

Flavored seltzer waters are safe to drink and enjoy in normal quantities. And, they can be a fun, healthy alternative to soda pops which can contain sugars and other ingredients that can impact our health when over-consumed.

If you have any questions about foods and ingredients, please reach out to us via email or submit your idea to us at go.msu.edu/cris-idea.