Image credit: Health Conscious People
As a mom of two, I started looking into glass baby bottles in October 2020, when a Trinity College Dublin study (1) showed that plastic bottles can shed millions of microplastics. We were one of the first blogs to write about this research in November 2020. This guide covers everything you need to know about glass bottles specifically: whether they’re safe, their pros and cons, and how to use them.
“The way you feed your baby is completely up to you. Formula fed is great! Breastfed is great!
Both allow you to bond with baby in different ways. No one should ever feel shamed.”
Stephanie Linda Paradiso
We totally agree with this view and leave this up to every mum to decide!
Related: 13 Non Toxic, Plastic Free Electric Kettles for a Healthy Cup
Why Parents Are Switching to Glass Baby Bottles
Research shows that plastic baby bottles shed microplastics, especially when heated. A 2020 Trinity College Dublin study found polypropylene bottles released between 1.3 and 16.2 million particles per liter (2) during normal formula preparation. Read what the research says about microplastics in baby bottles for the full details.
Pros and Cons of Glass Baby Bottles
| Pros | Cons |
|---|---|
| No microplastics from the bottle body | Heavier than plastic |
| Doesn’t stain, scratch easily or hold odors | Can break if dropped |
| Handles boiling water and sterilizing | Usually costs more |
| Lasts for years if undamaged | Nipple and collar may still be plastic or silicone |
| Easy to see how clean it is (contrary to stainless steel baby bottles) | Not ideal once babies hold the bottle alone |
| Easy to see the measurement on the bottle |
Related: Plastic Free Toys: Do Eco-friendly Alternatives to Plastic Toys Exist?
Borosilicate vs Tempered Glass: What’s the Difference?
Most glass baby bottles are made of one of two types of glass:
- Borosilicate glass contains boron trioxide, which makes it resistant to sudden temperature changes (thermal shock). It’s the best choice if you sterilize often or mix formula with hot water.
- Tempered soda-lime glass is heat-treated to make it stronger against knocks. If it does break, it shatters into small, blunt pieces rather than sharp shards, but it handles sudden temperature changes less well.
Check the product page or packaging for the type of glass, and look for bottles tested for lead and cadmium.
Related: 7 Best Plastic-Free Wet Wipes (100% Biodegradable, No Microplastics)
Check the Baby Bottle Nipple, Collar and Cap
The glass body is only part of the bottle. Most glass bottles still have a plastic screw collar (usually polypropylene) and a silicone or natural rubber nipple. Heated silicone nipples can also release particles, so look for designs with as few plastic parts as possible. See our 3 vetted non-toxic baby bottles for options with no plastic collar.
Related: Non-Toxic Baby Bottles: 3 Plastic-Free Picks (and What the Microplastics Research Says)
How to Sterilize Glass Baby Bottles Safely
- Check each bottle for chips or cracks before use, and replace any damaged bottle.
- Wash all parts in hot, soapy water and rinse well.
- Sterilize by boiling, steaming or using a dishwasher’s sanitize cycle, following the manufacturer’s instructions.
- Avoid sudden temperature changes: don’t move a bottle straight from the fridge into boiling water, or from boiling water onto a cold surface.
- Let the bottles air-dry on a clean rack.
How to Prepare Formula in a Glass Bottle
One advantage of glass is that you can mix formula directly in the bottle, rather than in a separate container. Follow the instructions on the formula container. For babies under 2 months old, born prematurely or with a weakened immune system, the CDC and FDA (3) recommend water at least 158°F (70°C) to kill Cronobacter. Cool the bottle quickly under cold running water, keeping the cooling water away from the nipple and cap, then test it on your wrist before feeding.
Related: Embracing Motherhood Sustainably with a Plastic-free Pregnancy Test
Glass vs Stainless Steel: When to Switch
Glass is ideal in the early months, when you hold the bottle during feeds. Once your baby starts holding the bottle or throwing it, many parents switch to a stainless steel bottle, which is unbreakable and also plastic-free.
FAQ about Glass Baby Bottles
– Are glass baby bottles heavy?
Yes, they’re heavier than plastic bottles, especially when full. A silicone sleeve adds grip and makes them easier for tired parents to hold.
– Can glass baby bottles go in the dishwasher?
Most can, but check the manufacturer’s instructions, especially for the nipple and sleeve.
– Do glass baby bottles contain lead?
Quality glass baby bottles should not. Painted or printed decorations can be a source of lead, so choose bottles with laser-etched markings and ask brands for lead and cadmium test results.
– How long do glass baby bottles last?
The glass body can last for years if it isn’t chipped or cracked. Replace nipples regularly, following the manufacturer’s guidance.
References and Scientific Literature Sources
(1) (3) Trinity College Dublin. (2020, October 19). High levels of microplastics released from infant feeding bottles during formula prep [Press release].
(2) Li, D., Shi, Y., Yang, L., Xiao, L., Kehoe, D. K., Gun’ko, Y. K., Boland, J. J., & Wang, J. J. (2020). Microplastic release from the degradation of polypropylene feeding bottles during infant formula preparation. Nature Food, 1(11), 746–754.
(3) U.S. Food and Drug Administration & Centers for Disease Control and Prevention. Help prevent Cronobacter illness: Prepare and store powdered infant formula safely.
—
Browse the I’m Plastic Free plaftorm for plastic-free alternatives to discover plastic-free baby products.
Add a comment