Baby bottle

drinking milk from a bottle A typical baby bottle has four components: the first is the main container or body of the bottle. A teat, or nipple, is the flexible part of the bottle that the baby will suck from, and contains a hole through which the milk will flow. The collar goes over the nipple and typically screws onto the neck of the bottle, forming a seal. Most, but not all baby bottles will also have a cap or travel cover that goes over the teat to keep it clean and to prevent small spills. Some bottles may optionally have a disposable liner. A bottle should also be comfortable for both caregiver and baby to use. Bottles that are lightweight and easy to hold can be desired by both babies and mothers. A variety of shapes are available. The design of containers, nipples or teats may mimic the shape of the mother's breast. Designers may try to mimic the flow rate of breastfeeding: the baby should be able to get enough nourishment, but at the same time not be overwhelmed or overfed. Materials Over time a wide variety of materials have been used for infant feeding vessels (see History). The materials now most commonly used in baby bottle containers are glass and some types of plastics. Food-grade stainless steel and silicone rubber are also used. Each of these four materials—plastic, glass, silicone and stainless steel—has advantages and disadvantages. A number of countries have regulations about allowable food contact materials. Ideally, the material making up the bottle should react as little as possible with the material in the bottle. No material is completely inert, but glass and stainless steel are relatively neutral materials which tend to remain stable and not interact with foods. Plastics are lightweight and resistant to breaking. A wide variety of plastics have been developed, some of which are not well understood in terms of reactivity. Some plastics have been found to be reactive with fluids such as breast milk and infant formula. Chemicals such as Bisphenol A (BPA) may "leach" from a bottle into the substance it holds. In addition, plastics may be more likely to break down when heated or cooled, for example, when being heated in a microwave or being boiled to sterilize them. Polycarbonate plastic was frequently used in baby bottles before 2011, and is still used in some countries. Polycarbonates contain Bisphenol A. Since 2008, Bisphenol S (BPS) and Bisphenol F (BPF) have been used as substitutes for BPA. They are structurally similar. Comparisons of BPA, BPS and BPF have found that these chemicals have similar potency and action to BPA and may pose similar dangers in terms of endocrine-disrupting effects. This has led to criticisms of the chemical industry and for calls to deal with bisphenols in groups, not individually. In 2021, the Canadian government agencies Environment and Climate Change Canada (ECCC) and Health Canada (HC) held consultations with the goal of grouping 343 known BPA analogs and functional alternatives. Polyethersulfone plastic (PES) does not contain BPA but does include Bisphenol S (BPS). An assessment of a variety of different baby bottles in use in 2016, reported 4 bottles to be of "high concern", 14 bottles to be of "concern"; and only 6 bottles to be of "no concern" These of "no concern" included two polyamide (PA) and two polyethersulfone (PES) bottles, a stainless steel bottle, and one of the 17 polypropylene (PP) bottles tested. Phthalates, found in polyvinyl chloride (PVC), are another area of concern. Referred to as "everywhere chemicals" because they are so common, phthalates make plastic more flexible, and have been used in pacifiers and nipples or teats for bottles. Phthalates have been banned from use in feeding bottles in the EU. In the US, there have been repeated calls for the removal of phthalates by the U.S. Consumer Product Safety Commission (CPSC) and others. Plastics labeled #3 may leach phthalates. Plastics may degrade over time in other ways, There are concerns that small beads of plastic may be released into fluids from some types of plastic bottles. In 2020 researchers reported that infant feeding bottles made out of polypropylene caused microplastics exposure to infants ranging from 14,600 to 4,550,000 particles per capita per day in 48 regions with contemporary preparation procedures. Microplastics release is higher with warmer liquids and similar with other polypropylene products such as lunchboxes. In 2022, the first study to examine the presence of plastic polymers in human blood found plastics of multiple types in the blood samples of 17 out of 22 healthy adults tested (nearly 80%). Medical experts have suggested reducing exposure to microplastics by not shaking plastic bottles or exposing them to high temperatures. Some recommend using alternative materials such as glass, silicone, or stainless steel. Baby bottle nipples (also called teats) are typically made from either silicone or latex rubber. When used for nipples, silicone is clear, durable, and slightly harder than latex. Natural rubber latex teats are elastic, tear resistant, and may feel softer. Latex can absorb odors, while silicone does not. Latex can break down if exposed to sunlight. Some people have allergies to latex. "Anti-colic" bottles have been put forward with the goal of reducing "gassiness" and distress when feeding. Designs often seek to minimize the sucking in of air by the baby while feeding. Some bottles try to minimize the mixing of air into the milk within the bottle. At the same time, it is desirable to avoid creating an internal vacuum as the infant sucks out fluids, since this will make it harder to feed. Designs may rely on the bottle's shape or incorporate different types of "venting". " bottle. Some vented bottles, as well as bottles which use a collapsible liner collapses as the formula is drained, have been assessed favorably. They were reported to be comparable to a breastfeeding group in terms of milk intake, sucking patterns, and oxygenation. Health recommendations for the storage and handling of human milk typically focus on preventing the growth of dangerous bacteria, but some research is also being done on nutrition. Experimental studies have shown a degradation of retinol (Vitamin A) and α-Tocopherol (Vitamin E) content dependent upon the formation of bubbles in expressed breast milk and in formula. Seven models of bottles were studied, from six companies. Less degradation occurred when using a bottle feeding system designed to minimize the mixing of air with the bottle's contents. Teat flow rate Teat characteristics can also have important implications for infant's sucking pattern and milk intake. Milk flow rate is defined as "the rate at which milk moves from the bottle nipple into the infant's mouth during bottle-feeding." In one study, nipples labeled "Slow" or "Newborn" (0–3 months) had flow rates ranging from 1.68 mL/min to 15.12 mL/min."The name assigned to the nipple type does not provide clear information to parents attempting to choose a nipple". Variations and accessories Bottles may be designed to attach directly to a breast pump for a complete "feeding system" that maximizes the reuse of the components. Such systems include a variety of drinking spouts for when the child is older. This converts the bottle into a sippy cup, a cup with lid and spout for toddlers, which is intermediate between a baby bottle and an open top cup. Bottles that are part of a feeding system may include handles that can be attached. The ring and teat may be replaced by a storage lid. Accessories for bottles include cleaning brushes, or bottle brushes, sterilizers, and drying racks. Brushes may be specially designed for a specific manufacturer's bottles and teats. Bottle sterilizers use different techniques for sterilization, including ultraviolet light, boiling water, and hot steam. Bottle warmers warm previously made and refrigerated formula. Coolers designed to fit a specific manufacturer's bottles are available to keep refrigerated formula cold. Special formula powder containers are available to store pre-measured amounts of formula so that caregivers can pre-fill bottles with sterile water and mix in the powder easily. The containers are typically designed to stack together so that multiple pre-measured amounts of formula powder may be transported as a unit. Institutions can purchase ready-to-feed formula in containers that can be used as baby bottles. The lid screws off and is replaced by a disposable teat when the formula is ready to be used. This avoids storing the formula with the teat and possibly clogging the teat holes when formula is splashed within the bottle and dries. == Use ==

Cleaning and sterilization Sterilization is a standard practice to prevent development of bacteria and resulting illness, that is more effective than sanitization. The Australian government and the United Kingdom's National Health Service guidelines recommend sterilization of baby bottles and other equipment either by using a cold water sterilizing solution such as by Milton sterilizing fluid, by steam sterilizing, or by boiling. It is important to clean and sterilize all parts of a bottle including containers, teats, and screw caps. The United States Centers for Disease Control and Prevention, suggests that it may be sufficient to clean bottles with soap and water, in a dishwasher or by hand. This recommendation is based on the assumption that water supplies are clean and sanitation standards are high. Some states, such as Illinois, continue to recommend sterilization in addition to washing. Alberta, Canada recommends sterilizing bottles that are used with formula until an infant is at least 4 months old. However, there is evidence that bacteria such as E. coli can thrive in biofilms which form on the interior walls of the bottles. Gentle rinsing is not enough to prevent this. Even in developed areas, contamination continues to be a concern. In 2009 in the United Kingdom, researchers found contamination with Staphylococcus aureus in 4% of the baby bottles that parents reported were ready to fill after cleaning and disinfecting. In lower-resource settings, risks of exposure to dangerous respiratory and enteric infections are higher. A study of children admitted to hospital in Rawalpindi, Pakistan, found that 52.1% of the bottles their caregivers considered clean were actually contaminated. This occurred even though caregivers reportedly followed many of the recommended cleaning practices for cleaning and sterilizing bottles. The most common mistake was to boil the bottles for less than the minimum time recommended by WHO. Research into the preparation of infant formula in South Korea indicates significant levels of contamination can be transmitted through the handling of spoons and other utensils. Spoons, after being touched, were often left in the formula container, allowing bacteria to spread to the formula in the container. C. sakazakii, S. enterica, and S. aureus, all of which are potentially fatal, were able to surviving for weeks in contaminated infant formula. Understanding how recommendations are interpreted is important: in one study, leaving a bottle in water that had been previously boiled in a kettle was believed to be "boiling" the bottle. Researchers emphasize that health providers need to better educate caregivers; and that practical methods of bottle hygiene need to be suited to use in field settings. For example, in Peru, easy-to-adopt practices like using a bottle brush and detergent gave greater advantages than difficult-to-achieve procedures like boiling a bottle. Age-appropriate use Nipples (teats) are typically subdivided by flow rate, with the slowest flow rate recommended for premature infants and infants with feeding difficulties. However, flow rates are not standardised and vary considerably between brands. The AAP recommends that the cup be introduced by one year of age and that the use of the bottle by discontinued by 18 months. The use of bottles is discouraged beyond two years of age by most health organisations as prolonged use can cause tooth decay. Early childhood caries (ECC) is also a concern when considering how long breastfeeding should continue. ==Regulation==

While infant formula is highly regulated in many countries, baby bottles are not. Only the materials of the teat and bottle itself are specifically regulated in some countries (e.g. British Standards BS 7368:1990 "Specification for babies' elastomeric feeding bottle teats"). In the US, the Food and Drug Administration (FDA) regulates teats and the bottle materials. In 1985 the FDA restricted allowable levels of nitrosamines (many of which are carcinogens) released from bottle teats. Tests of bottle nipples available in the US, Singapore, West Germany, England, Japan and Korea suggest that levels of nitrosamines in most rubber baby bottle teats are within recommended standards. Another chemical that has been regulated is Bisphenol A (BPA), described as an endocrine disruptor in 1991. Concerns about BPA have been supported by further work. (Research into the effects of BPA has frequently been hotly contested and controversial and issues have been raised over research biases due to industry funding and conflicts of interest due to close ties between government consultants and BPA manufacturers. In 2008 Walmart announced that it would stop selling baby bottles and food containers containing BPA. As of 2017, these were applied in at least 40 countries. in China, in Malaysia, and South Africa. In July 2012, the FDA stated that BPA would no longer used in baby bottles and sippy cups, in response to a petition from the American Chemistry Council stating that this was now in line with industry practice. Other countries such as Argentina and Brazil followed suit by prohibiting bisphenol A in baby bottles. There are calls for increased regulation of BPA in India. ) ==History==

Throughout most of human history, infant nutrition has primarily depended on the availability of the child's mother or a wet nurse to breastfeed the infant. As early as , Egyptian pottery shows images of women breastfeeding their babies and also using animal horns to feed them. Examination of the organic residues on ancient ceramic baby bottles shows that they were used as early as to feed babies with animal milk. In the United States, the first glass nursing bottle was patented by C.M. Windship in 1841. It was intentionally shaped like the mother's breast. In 1845 the Alexandra Feeder was marketed in England. In Paris, the "Biberon" was introduced by M. Darbo: it was reported to be quite popular in a review from 1851. As the group American Collectors of Infant Feeders notes, by "the late 1800s a large variety of glass nursing bottles were produced in the United States", and the U.S. Patent Office had issued more than 200 patents for various designs of nursing bottles by the 1940s—designed to lie flat or stand up straight, with openings on their sides or ends, with detachable or permanently attached nipples, etc. The design of baby bottles and particularly the ease of cleaning them had potentially serious consequences for the health of the children using them. Estimates of infant mortality suggest that 20-30% of infants died in the first year of life during the late Victorian era. A bottle with a long Indian rubber tube ending in a teat remained popular until the 1920s because even very young babies could feed independently. The feeding tubes could be bought separately and were sometimes used with empty whiskey or medicine bottles. Almost impossible to keep clean, this type has been nicknamed the "murder bottle". Heat-resistant Pyrex bottles were introduced to the American and British markets at different times. Pyrex bottles were first introduced in the United States by Corning Inc. in 1922. They were offered in three shapes (narrow neck, wide mouth, and flat) and multiple sizes, for a total of ten varieties. By 1925, the product line had been limited to a small subset of the original shapes and sizes. In the 1950s an upright Pyrex bottle with a narrow neck was introduced. In the 1960s a wide-neck version was finally introduced to the UK market. Soft nipples of various materials were introduced early in the history of feeding (e.g., leather, cork, sponge, dried cow's teat filled with cloth). Many were very difficult to clean and when unsanitary could pose a serious threat to infant health. Although Elijah Pratt of New York patented the first rubber nipple in 1845, including the first disposable collapsible liner for a baby bottle. Her patent was one of many attempts to design a bottle to limit swallowing of air during feeding, and reduce gastric upset and spitting up. A plastic bottle with a disposable liner was eventually tested at George Washington University Hospital and marketed by Playtex. Innovations such as the introduction of a working check valve in the nipple (to provide unidirectional flow of the liquid food) appeared as early as 1948 in a patent to J.W. Less. This technology was picked up by others including Owens-Illinois Glass, eventually making its way into Gerber and all modern pressure-balancing bottle designs. It is also used for adult drinking cups and various other products requiring fluid flow under vacuum. The modern business of producing bottles in the developed world is substantial. For 2018, the global baby bottle market was valued at US$2.6 billion. In 1999 it was reported that the UK "feeding and sterilising equipment sector ... stands at £49m… [where] [s]ales of feeding bottles account for 39%" or £19.1m of that market. ==Controversy==

The 2014 summary policy statement of the American Academy of Pediatrics (AAP) makes no specific mention of bottle feeding, but makes clear that "[b]reastfeeding and human milk are the normative standards for infant feeding and nutrition", and refers to decisions regarding the supply of infant nutrition as "a public health issue and not only a lifestyle choice… [g]iven the documented short- and long-term medical and neurodevelopmental advantages of breastfeeding". The AAP policy recommends breastfeeding exclusively for six months, continuing it with introduction of complementary foods, with an overall duration of "1 year or longer as mutually desired by mother and infant". In response to public pressure felt from policies de-emphasizing bottle- and formula-feeding, efforts have arisen to support mothers experiencing physiologic or other difficulties in breastfeeding, and sites include individual views that attempt to weaken the scientific case of the AAP policy; a book of the personal experiences and views of one mother committed to bottle/formula feeding, Bottled Up, by Suzanne Barston, has appeared. In 2007, a group of 38 researchers examined 700 studies into the use of the chemical compound Bisphenol A in plastics manufacturing, and warned that very low levels of exposure to the chemical can potentially pose adverse health effects, especially to a developing fetus. In 2024, multiple baby bottle companies, including Nuk, Tommee Tippee, and Dr. Brown's, were involved in a class action lawsuit for their bottles leaching microplastics when heated. ==See also==