Inaccurate baby bottle markings pose a health risk

An Australian study has found more than half of infant feeding bottles have inaccurate or missing markings, sparking calls for the introduction and enforcement of industry standards for bottles to prevent babies from becoming ill.

Adjunct Associate-Professor Karleen Gribble from the School of Nursing and Midwifery and her colleagues at the University of Western Sydney purchased the entire range of infant feeding bottles available for sale in Australia.

The team found one in five bottles had at least one marking that was deemed so inaccurate that it would fail to meet the requirements of the only existing standard for bottles in the world, the European standard. Markings underestimated and overestimated actual volumes by as much as 43%.

In addition, two-fifths of the bottles were missing at least one marking for a volume that instructions for reconstituting infant formula require parents to measure. In total, 57% had either inaccurate or missing markings.

“Parents using infant formula are routinely instructed to use the volume markers on the bottles to measure water, but this advice assumes that bottle volume markers are accurate,” said Associate Professor Gribble.

Expensive bottles no more accurate

Of the bottles examined, 41% of bottles claimed compliance with the European Standard, 6% with non-existent Australian standards and 54% of bottles had no standard claim.

The bottles claiming compliance with the European standard were just as likely to be inaccurate as those that made no claim, and expensive bottles were no more accurate.

Associate Professor Gribble said the potential health implications included dehydration, excessive weight gain, constipation and exacerbation of reflux symptoms. The greatest risk is for very small or premature infants who lack the capacity to deal with over-concentration of formula. Under-concentrated infant formula could result in poor growth and development due to inadequate nutrition.

Associate-Professor Gribble said disposable liner bottle systems that use a disposable insert to contain liquid are particularly inaccurate, and volume markings on them should be prohibited to prevent them being used to measure water.

The study has been published in the journal of Maternal and Child Nutrition.