Bloom Glass Feeding Bottle

Details

A feeding bottle in borosilicate glass, with a platinum-cured silicone teat and a polypropylene collar. Three materials, all named. Glass is not one thing, and this is where the category is loose. Most bottles sold as glass are soda-lime, the glass a drinking tumbler is made from, with a coefficient of linear thermal expansion around 9 x 10 to the minus 6 per kelvin. Borosilicate 3.3 to ISO 3585 expands at 3.3, which is where the name comes from, and that difference is the whole reason one cracks when you pour boiling water into a cold bottle and the other does not. This bottle is tested through a 120 K shock by ISO 718 and comes out intact. A pack that says glass and nothing else is telling you the cheaper answer. The teat is platinum-cured silicone and its flow rate is a measured number, not an adjective. Slow flow, supplied with the bottle, runs at 6 ml per minute on water at 20 C to EN 14350. Medium is 12 and fast is 20. Flow matters more than most parents are told: if milk runs from the corners of the mouth, if your baby gulps or pulls off, the teat is too fast, and moving down a flow does more than any other single change. The vent at the teat base is sold everywhere as anti-colic. The evidence for that is thin and we are not going to make the claim. What a vent reliably does is let air back into the bottle so the teat does not collapse mid-feed and your baby is not sucking against a vacuum. That is worth having on its own. BPA and BPS again cannot be present: glass and silicone are outside bisphenol chemistry, and the collar is polypropylene to IS 10910. Nothing was removed and nothing was substituted.

• Borosilicate 3.3 to ISO 3585, wall 2.4 mm, thermal shock 120 K by ISO 718
• Platinum-cured silicone teat, single hole, vented at the base, no latex and no smell
• Flow measured to EN 14350: slow 6 ml per minute, medium 12, fast 20, all on water at 20 C. Slow flow is in the box, medium from about 3 months and fast from about 6, sold on their own
• N-nitrosamines below 0.01 mg per kg and nitrosatable substances below 0.1 mg per kg on the teat
• Overall migration below 10 mg per square decimetre, run on the bottle assembled with teat and collar and filled with simulant at 100 C. Not on a pellet
• Collar and cap polypropylene to IS 10910. Removable silicone sleeve for grip
• Wide 52 mm neck, so a hand and a brush both fit
• 120 ml weighs 190 g empty and 240 ml weighs 290 g, about three times a polypropylene bottle. Glass is heavier and that is the deal
• Honest trade-off: it will break. A silicone sleeve reduces the odds and does not remove them, and a bottle with a chip in it goes in the bin, not back in the steriliser. Check the rim every time you wash it
• Never warm milk in a microwave. It heats unevenly and the cool patch you test on your wrist is not the mouthful that scalds
• Replace the teat every 2 months, or sooner if it is cloudy, sticky, swollen or torn. Pull it gently before each feed to check it is sound
• Mother's milk is best for your baby. A feeding bottle should be used only on the advice of a health worker. The notice is required by the Infant Milk Substitutes, Feeding Bottles and Infant Foods Act 1992