The short answer: yes, bottled water is fine for preparing infant formula — but with specific conditions on sodium content, fluoride content, and preparation method. Not all bottled water is appropriate, and tap water meeting the same thresholds is equally suitable. This article unpacks the criteria and the practical preparation protocol.
The preparation protocol below follows CDC formula preparation guidance plus American Academy of Pediatrics formula-feeding guidance. For the bottled-water regulatory framework, see FDA 21 CFR Part 165.
Two thresholds to check on the bottle label
When choosing bottled water for formula preparation, verify two specific values on the nutrition or mineral content label:. The detail below applies to the typical preparation environment most US households operate in; specific pediatric situations may warrant additional precautions per your physician.
1. Sodium content: ≤200 mg per liter (≤200 mg/L). Higher-sodium bottled water (some "mineral water" varieties contain 500-1,500+ mg/L sodium) can stress infant kidneys and contribute to imbalanced electrolyte status. Look for "low sodium" labeling specifically; many bottled-water brands list sodium content per serving rather than per liter, so do the math (typically 8 oz / 237 mL serving).
2. Fluoride content: ≤0.7 mg per liter (≤0.7 mg/L). Excessive fluoride exposure in formula-fed infants can increase risk of dental fluorosis. The 0.7 mg/L threshold matches the CDC formula preparation guidance recommendation. Many bottled water brands don't list fluoride specifically; if unlisted, check the brand's water quality report online (most brands publish these annually).
If the bottled water meets both thresholds, it's appropriate for formula preparation following the boil-and-cool protocol below. If either threshold is exceeded or unverified, choose a different bottled water or use filtered tap water meeting the same thresholds.
What bottled water types work
Purified water (reverse osmosis, deionized, or filtered) typically meets both thresholds and is the simplest choice. Brands like Aquafina, Dasani, Smartwater (purified variants) typically meet the criteria — verify on the specific label.
Spring water typically meets the criteria but varies by brand. Look for low-sodium-labeled spring water specifically.
Nursery water (specifically marketed for infant formula preparation) is reverse-osmosis-purified water with added fluoride removed and meets all preparation requirements. Often the simplest single-purpose choice for families specifically buying water for formula preparation.
Mineral water is the principal water type to AVOID for formula preparation. Mineral water typically contains 100-1,500+ mg/L sodium and 0.5-3+ mg/L fluoride — exceeding the formula-preparation thresholds. The mineral content that makes mineral water beneficial for adults is inappropriate for newborn formula preparation.
Distilled water is technically safe for formula preparation (meets sodium and fluoride thresholds at zero) but is generally NOT recommended because it lacks the trace minerals that contribute to bone development and electrolyte balance. Standard purified or spring water is the better choice.
Tap water as an alternative
Tap water meeting the same sodium and fluoride thresholds is equally appropriate for formula preparation. For US municipal tap water:
- Sodium content is typically below 50 mg/L in most US municipal systems (well within the threshold). Some areas with naturally saline groundwater or specific water-treatment additions may exceed this; verify with your local water authority's annual Consumer Confidence Report.
- Fluoride content is typically 0.5-1.0 mg/L in fluoridated US municipal water (right at or slightly above the 0.7 mg/L threshold). For fluoridated areas, using filtered tap water (pitcher filter, faucet filter, or whole-house RO) reduces fluoride to appropriate levels. Or use bottled water specifically labeled low-fluoride.
For families on private well water, get a complete water test (sodium, fluoride, nitrates, lead, contaminants) before using for formula preparation. Well water is not categorically appropriate without testing — some well water has naturally high contaminant levels.
The CDC preparation protocol
CDC formula preparation guidance specifies the safe preparation steps regardless of water source:
- Wash hands thoroughly before preparation
- Use clean, sterilized bottles — sterilize new bottles before first use; sterilize before each preparation in the first 2-3 months
- Boil water (whether tap or bottled) for 1-2 minutes
- Cool to ~70°C (158°F) before adding powder — this is the standard temperature that kills potential Cronobacter or other pathogens in powder while not destroying nutrients
- Add powder per manufacturer's specific scoop instructions for the specific formula
- Cool to body temperature (~37°C / 98°F) before feeding
- Discard any unused prepared formula within 1 hour of feeding start — don't refrigerate partially-fed bottles
The 70°C step is critical. Powdered infant formula is not sterile and may contain trace amounts of Cronobacter or other pathogens at manufacturing. The 70°C reconstitution kills potential pathogens in the powder. Lower-temperature reconstitution (room-temperature water, body-temperature water) does not provide this pathogen elimination.
Special situations
Baby has chronic kidney disease or sodium-restricted diet: use distilled water or specifically nursery-water-grade purified water under pediatrician guidance. Standard mineral content in purified water is fine for healthy infants but may be too much for infants with specific medical conditions.
Baby has fluorosis history or dental concerns: use specifically fluoride-removed bottled water (nursery water, RO-filtered tap water) as the primary preparation water. Fluoride exposure accumulates over time; chronic-low-level reduction matters.
Travel: bottled water is the practical travel solution. Verify sodium and fluoride content on the specific brand label, or use nursery-water-grade products (Nursery Water, Gerber Pure) which are formulated specifically for infant formula preparation.
Hospital nicu/post-discharge: follow your hospital's specific discharge instructions. Some NICU protocols specify particular preparation water types for premature infants or infants with specific conditions.
Common bottled water types — quick reference
| Type | Sodium | Fluoride | Suitable? |
|---|---|---|---|
| Nursery water (Gerber Pure, Nursery Water) | under 10 mg/L | Removed | ✓ Best for formula |
| RO-purified bottled (Aquafina, Dasani purified) | under 10 mg/L | Removed | ✓ Suitable |
| Spring water (low-sodium variants) | under 50 mg/L | Variable — verify | ✓ Suitable if fluoride OK |
| Mineral water | 100-1,500+ mg/L | Variable | ✗ Avoid for formula |
| Distilled water | 0 mg/L | 0 mg/L | ⚠ Safe but lacks minerals; not recommended |
| Filtered tap water (pitcher / faucet RO) | varies by area | reduced via filter | ✓ If meets thresholds |
| Unfiltered tap water (US municipal) | typically under 50 mg/L | typically 0.5-1.0 mg/L | ⚠ May exceed fluoride threshold |
| Private well water | Variable | Variable | ⚠ Test before using |
Related reading
- Can I mix two different baby formulas in the same bottle?
- Best formula for newborns
- Best baby formulas
- How much does baby formula cost per month?
This site provides research and comparisons, not medical advice. Consult your pediatrician before changing your baby's formula.