The short answer
Start with what each word tells you. In US FDA guidance, spring water describes the source, mineral water has a defined amount of naturally occurring dissolved solids, and purified water has been treated to meet a standard. None of those words alone tells you which bottle you will like best.
Research-based editorial guide, not a hands-on product test or medical review. No paid placement or affiliate links in this guide. How we work.
- The definitions below are US FDA definitions; check local terminology elsewhere.
- Source category and treatment are separate things to investigate.
- Compare ingredients and documentation before drawing quality conclusions.
| Label | Main question answered | Useful next check |
|---|---|---|
| Mineral water | What source-derived mineral category is it? | Named minerals and units |
| Spring water | Where does the water originate? | Named spring and collection information |
| Purified water | What processing standard does it meet? | Treatment and any added ingredients |
| Flavoured or nutrient-added water | What else is in the beverage? | Ingredients and nutrition label |
The definitions, with the market made explicit
FDA's mineral-water definition requires an underground source and at least 250 parts per million total dissolved solids; the minerals must come from the source. Spring water can be collected at the spring or through a qualifying borehole. Water treated by distillation, reverse osmosis or another suitable process may qualify as purified water.
Use these definitions for US bottles. If you are shopping elsewhere, check the local rules. For an imported bottle, keep the source country and country of sale separate: the water may come from one place while its label follows the rules of another.
Evidence: FDA: Bottled Water Everywhere — US definitions and safety oversight
Separate the source from what happens afterwards
FDA notes that some bottled water starts with a municipal supply. Ask where the water came from and what was done before bottling. Both answers help you understand the bottle; the source name alone does not describe the whole process.
For flavoured water or water with added nutrients, FDA requires those additions in the ingredient list. Look there if you want to know whether minerals or flavourings were added. Compare plain water with plain water first, then look at flavoured versions as a separate choice.
Evidence: FDA: Bottled Water Everywhere — US definitions and safety oversight · FDA: Bottled, Flavored and Nutrient-Added Water Beverages
A useful four-step label check
First, read the full product name. Second, check the ingredients for additions. Third, look at any nutrition information that matters to your choice. Fourth, find the product's report if you have a question the label cannot answer. Ask the maker about a missing detail instead of borrowing a number from another brand.
For example, you might want plain water to carry to work, or a flavoured drink to replace your usual sweetened one. For the first job, narrow the shelf to plain options. For the second, check the ingredients and portion you will drink before choosing.
Evidence: FDA: Bottled, Flavored and Nutrient-Added Water Beverages · CDC: About Water and Healthier Drinks
Match the choice to what you will use
For a bottle to carry, think about the space in your bag. For home, compare cost per litre and a pack size you expect to use. If you prefer a named spring or a particular treatment method, use that preference to narrow your options before comparing price.
CDC recommends water as an alternative to sugary drinks and notes that water needs vary. Choose something you can afford and enjoy within any fluid advice you have received. There is no need to buy a more expensive bottle simply because its category sounds more appealing.
Evidence: CDC: About Water and Healthier Drinks
What the category cannot settle
FDA has separate requirements for water names, contaminants and manufacturing. If safety is your question, look beyond the category to the information about that particular product. Write down what you want to check, then look for the relevant test or ask the maker where to find it.
For infant formula or a prescribed medical diet, follow the instructions for that use and ask your care team about water choice. A general guide to label names cannot settle those questions. Keep the bottle or its details handy so you can ask about the exact product.
Evidence: FDA: Bottled Water Everywhere — US definitions and safety oversight
Common questions
Does purified mean that no minerals remain?
Do not infer a final mineral profile from that word alone. Record the stated treatment and check the finished product's ingredients and available mineral information.
Is spring water always the best choice?
The spring category identifies an origin, not the winner of a comparison. Decide which practical attributes you want and examine product-specific information.
Can I apply the FDA definitions everywhere?
No. This is a US reference. Read the local label and relevant local definitions before comparing products sold in another market.
Sources & transparency
Manufacturer information describes its product, not an independent endorsement. Food, tea and supplement studies are not interchangeable.
- FDA: Bottled Water Everywhere — US definitions and safety oversight
government source · Checked 2026-10-22
- FDA: Bottled, Flavored and Nutrient-Added Water Beverages
government source · Checked 2026-10-22
- CDC: About Water and Healthier Drinks
government source · Checked 2026-10-22
Found an error? Send the page URL and supporting source. General education, not a diagnosis, treatment plan or substitute for professional advice.