The science behind wet wipes for infant skin
In the diapered area, the continuous exposure to excess moisture and irritants from urine and feces weakens the stratum corneum, making the skin more susceptible to irritation. The use of wet wipes for infants (baby wipes) is a common practice to clean skin after urine or a bowel movement, and this practice even extends to cleaning the hands and face, resulting in repeated daily use. Therefore, ensuring that baby wipes contain ingredients that are safe and mild on skin is important to help minimize skin irritation and discomfort. While disposable baby wipes have been shown to be effective and gentle at cleaning infant skin, even the skin of premature infants, there is growing public concern regarding their safety and tolerability. Not all products are made the same, as differences exist in manufacturing processes, ingredients, materials, safety, and quality testing. Therefore, it is important that healthcare professionals have accessible evidenced-based information on the safety and tolerability of common ingredients found in baby wipes to optimally educate their patients and families. Herein, we provide a review on best practices for ingredient selection, safety, and efficacy of baby wipes.
Skin irritation in the diapered region (commonly referred as diaper dermatitis) is one of the most common skin disorders found in infancy, with the highest incidence at 9-12 months of age.1 Overhydration and prolonged exposure to urine and feces are known to be the main contributors to skin irritation in the diapered area.2 However, an infant's diet, medications, underlying skin conditions, certain product ingredients, caretaker behavior, and practices such as infrequent diaper changes or ineffective cleaning can also influence the occurrence of diaper dermatitis. It has been reported that the diapering process can be a stressful event for an infant.3 The presence of skin irritation can exacerbate this response, leading to increased pain and discomfort. Ensuring the diapered area is kept dry and clean and that products used do not adversely impact the skin can help minimize the occurrence of dermatitis in the diapered region and, in turn, provide comfort to the infant.
Herein, we provide a review on best practices for ingredients selection, safety, and efficacy of runhe baby soft wet wipes to help make more informed decisions when selecting products for infant diapered skin care.
Surfactants are the molecules within the formulation that provide cleaning action. Surfactants contain hydrophilic moieties attached to hydrophobic end chains. It is the hydrophobic end chains that bind to oily residue on the skin surface and help remove it. For baby wipes, it is important to use a surfactant that can adequately remove the oily molecules within feces without removing skin lipids, which can lead to skin barrier damage with repeated or prolonged use. For runhe new arrival baby wipes, the surfactant fraction would not be expected to exceed 1% by weight of the formula and, in most cases, would be below 0.3% by weight.6 This is in stark contrast to bottled baby products (body wash, shampoo, hand soap) where the surfactant concentration is typically between 5% and 20% by weight as dilution is expected upon use followed by rinsing.6
In the personal care industry, the default listing of preservative chemicals is maintained by the European Union (EU) and is known as Annex V.7 Ingredients on this list are recognized for their antimicrobial action and listed with acceptable and safe usage concentrations. A subset of these chemicals applicable to baby wipes is shown in Table 3. Notably, many of the chemicals in Annex V are not allowed for use in children's products due to regulation at the state or country level. The US FDA does not maintain a list of approved preservatives but does have the authority to limit the use of ingredients in certain product classifications. After considering safety, allergenicity and irritation potential, the choice of preservative in a formulation depends on water solubility, effective concentration, pH compatibility, odor, and consumer expectation. A good example of regulatory and industrial response has been the removal of formaldehyde donating preservatives and MI from wipes and other leave-on products following many reports of contact dermatitis and sensitization in the diapered area and in other common areas of baby wipes use such as hands and face. Currently, it is rare to find this ingredient in mainstream baby soft wet wipes.
Any products that have a water activity level of >0.90 are susceptible to the growth of microbes in the product as this is the minimum level of water required for bacteria and fungi to grow.22-24 As such, products at or exceeding this level of water, such as wipes, should include a preservative to prevent the growth of microbes that may be introduced post-manufacturing. A likely route of post-manufacturing product contamination is while dispensing the product during use,25 a reason why packaging is a key component. In this scenario, transient or normal flora from a wipes’ user can transfer from the hands onto the stack of wipes in the product package. To assure a newborn baby wipes product is effectively preserved and able to overcome this type of contamination, a confirmatory lab test must be utilized to ensure microbial growth will not occur during normal product use. Specifically, the test should involve adding a defined number of diverse organisms (at a minimum those recommended by USP/EP but others may be added) to a defined quantity of product and then monitoring the survival and/or growth of the added organisms over time.26 This test is commonly utilized on product that has been freshly made and on product aged under ambient or accelerated (high temperature, high relative humidity) conditions. While there is no universally applied approach in how this test is conducted for wipes, many manufacturers utilize USP and/or EP guidance as the basis for establishing their method and acceptance criteria.