Assessment of infant mattress firmness: a do‐it‐yourself safety test to reduce the risk of asphyxiation

Overly soft infant sleep surfaces have been clearly associated with asphyxiation, but no international product standards require a minimum firmness and no definition of ‘firm enough’ is available to parents. With a do-it-yourself test, caregivers could assess the firmness of infant sleep products, whether they are newly purchased, already owned, or borrowed. Many parents have the mistaken belief that infants require the same degree of softness as adults (see, for example, Ajao, et al.) and therefore they are tempted to add padding to infant sleep surfaces. A do-it-yourself test would help to discourage such risky practice. A do-it-yourself test would also be of use to child care and other institutions that cater for infants younger than 12 months of age. Finally, a do-it-yourself test might bolster the efforts of health professionals to discourage inappropriate co-sleeping, by demonstrating that the prospective co-sleeping surface was too soft for safe infant use. The only death-scene investigation to formally measure the softness of the sleep surface, for both fatal cases and matched controls, was reported in 2010. Schlaud et al., working in Germany, utilised a purpose-built instrument to assess surface firmness. Subsequent statistical analysis suggested a pass-fail performance criterion by which to identify sleep surfaces with an average three-fold excess risk of death. By experimentation, across 34 surfaces of varying firmness, a substitute test method was discovered that matched, for all but one case, the results produced by the German test instrument. This substitute method relied only on some common household items: two unopened one-litre milk (or juice) cartons and a dozen computer disks held in a tight stack with kitchen cling wrap. The stack of computer disks was positioned on the sleep surface at the worst-case location, i.e. the location considered to maximise the chance of failure. The cartons were then laid sideways on top of the stack of disks to form a level tower (of approximate total mass 2,325 g), with the overhang of the lower carton set at 40 mm. If the overhanging section of the carton made any contact at all with the mattress being tested, then the mattress failed the test. A schematic diagram and reference list are published with the article. Language: en