Infant and Toddler Wet Wipe Testing

Infant and toddler wet wipe inspection mainly conducts scientific testing and analysis on microbiological indicator testing, chemical safety testing, pH value determination, preservative content and type analysis, irritation testing, and wiping performance and material testing, objectively assessing the product quality grade and issuing a detailed test report, providing a basis for manufacturers' quality control and downstream users' product acceptance.

Testing Items

Microbiological indicator testing: Detects the total bacterial count, total fungal count and the presence of the pathogenic bacteria (such as the coliform group, Pseudomonas aeruginosa and Staphylococcus aureus) in the wet wipe products. This item is directly related to the hygiene and safety of the product, and is particularly crucial for the fragile skin of the infants and the possible accidental ingestion risks.

Chemical safety testing: Emphatically detects the chemicals remaining in the impregnating solution of the wet wipe or after wiping, including the migratable fluorescent whitening agents, methanol, formaldehyde and extractable heavy metals (such as lead, cadmium, mercury and arsenic). These substances may enter the body through the skin contact or the infants sucking their fingers, and must be strictly controlled within the safe limits.

pH value determination: Determines the acidity and alkalinity of the aqueous extract of the wet wipe. The pH value of the infant skin is about 5.5, which is weakly acidic. The pH value of the wet wipe should be close to neutral or weakly acidic, to avoid destroying the natural protective barrier of the skin and causing the irritation or allergic reactions.

Preservative content and type analysis: As a water-based product, the wet wipe is easy to breed microorganisms and needs to add the preservatives. The specific contents of the commonly used preservatives such as the methylchloroisothiazolinone/methylisothiazolinone, phenoxyethanol and parabens are detected, ensuring compliance with the limit and prohibition requirements of the relevant regulations.

Irritation testing: The potential irritation or sensitization of the product to the skin is evaluated through the in vitro cytotoxicity testing or the human skin patch testing. Especially for the infant and toddler wet wipes marked as "fragrance-free" and "suitable for the sensitive skin", this item is the important basis for verifying their mildness.

Wiping performance and material testing: Evaluates the softness, tensile strength, abrasion resistance, pilling situation and the liquid carrying and releasing ability of the nonwoven substrate. The good wiping performance ensures the effective cleaning, while avoiding the physical friction damage to the skin caused by the rough material or the lint shedding.

Testing Scope

Ordinary cleaning and care wet wipes: Applicable to the daily cleaning of the hands, face and buttocks of the infants and toddlers, mainly testing their basic cleaning ability, mildness and conventional safety indicators. This is the most common category on the market, and the testing needs to cover all the claimed use parts.

Hand and mouth dedicated wet wipes: Specially designed for cleaning the hands and the area around the mouth of the infants and toddlers, with the highest safety requirement grade. In addition to the conventional items, the testing scope particularly emphasizes the migratable hazardous substances, the safety standards of the food contact materials and the stricter microbiological limits.

Functional wet wipes containing the skincare ingredients: The wet wipes with the added ingredients such as the vitamin E, lanolin and plant extracts. The testing scope needs to be extended to the qualitative and quantitative analysis of the added active ingredients, their stability and the compatibility with the substrate, and evaluate the claimed effects such as the moisturizing and soothing.

Nonwoven raw materials: Detects the fibre composition, grammage, fluorescent substances and migratable substances of the nonwoven (such as the spunlace nonwoven) used in the wet wipe. The safety of the raw materials is the basis of the safety of the finished products, and needs to be controlled from the source.

Impregnating solution (care solution): The independent testing is carried out on the liquid components in the wet wipe, including the quality of the purified water or deionized water, the types and concentrations of all the additives, and the stability of the solution. This is the core of the chemical safety of the wet wipe.

Packaging materials: Detects the sealing performance and barrier performance of the wet wipe packaging bags, as well as the hazardous substances in the packaging materials (such as the plastic films) that may migrate to the product, ensuring that the product maintains the sterility or micro-ecological stability within the shelf life.

Testing Methods

Microbiological limit examination method: In accordance with the "Pharmacopoeia of the People's Republic of China" or GB 15979-2002 "Hygienic standard for disposable sanitary products", the plate count method is adopted to determine the total bacterial and fungal counts, and the specific pathogenic bacteria are detected through the selective media and biochemical identification methods.

High-performance liquid chromatography method: Used to precisely determine the contents of the various preservatives, formaldehyde, fluorescent whitening agents and specific functional additives in the wet wipe. This method has high separation efficiency and good sensitivity, and is the mainstream technology for the quantitative analysis of the complex chemical components.

Atomic absorption spectrometry/inductively coupled plasma mass spectrometry: Used to detect the trace heavy metal elements in the extraction solution of the wet wipe. The ICP-MS method has a lower detection limit and a wider dynamic range, and can determine multiple heavy metals at the same time, ensuring the precise and reliable results.

pH meter determination method: A calibrated precision pH meter is used. After a certain amount of the wet wipe sample is extracted with the carbon dioxide-free water, the pH value of the extract is directly determined. The operation needs to be carried out at the constant temperature, to reduce the influence of the temperature on the determination.

Skin irritation in vitro testing: The commonly used methods include the reconstructed human epidermis model testing, in which the sample acts on the artificial skin model cultured in vitro, and the potential irritation is objectively evaluated by detecting the indicators such as the cell viability (MTT method), conforming to the principle of the animal testing alternatives.

Physical property testing method: An electronic fabric strength tester is used to test the longitudinal and transverse breaking strengths and elongation of the nonwoven; a softness tester is used to evaluate the hand feel; and the standard friction device is used to test its abrasion resistance and lint shedding rate.

Testing Standards

Domestic Standards:

1. GB/T 27728, Wet wipes

2. GB 15979-2002, Hygienic standard for disposable sanitary products

International Standards:

1. Regulation (EC) No 1223/2009 on cosmetic products

2. ISO 17516, Cosmetics — Microbiology — Microbiological limits

Note: The applicable standard can be selected according to the product use and customer trade requirements; standards agreed in the contract take precedence over general standards.

Testing Instruments and Equipment

Biological safety cabinet and constant temperature incubator: Used for the pre-treatment and aseptic operation of the microbiological testing samples. The biological safety cabinet provides a clean environment to prevent the contamination, and the constant temperature incubator provides the stable temperature conditions for the microbial growth (such as 30-35 ℃ for the bacteria and 20-25 ℃ for the fungi).

High-performance liquid chromatograph: Equipped with a UV detector or diode array detector, used to separate and detect the organic compounds in the wet wipe. Through the comparison with the standard substances, the contents of the components such as the preservatives and fragrance compounds can be accurately quantified.

Inductively coupled plasma mass spectrometer: The key equipment for the ultra-trace heavy metal analysis. The high-temperature plasma source can completely atomize and ionize the sample, and then the separation and detection are carried out through the mass spectrometry, with the extremely high sensitivity, reaching the ppb (parts per billion) level or even lower.

Precision pH meter and electronic balance: The pH meter needs to be equipped with a combined electrode, with the precision of 0.01 pH unit, and regularly calibrated with the standard buffer solutions. The high-precision electronic balance (with the sensitivity of 0.1 mg) is used to precisely weigh the samples and reagents, and is the basis of the chemical testing.

Mechanical property testing instrument: i.e., the universal material testing machine, equipped with the dedicated fabric fixtures, which can test the tensile strength, tearing strength and elongation of the nonwoven substrate according to the standard methods, quantitatively evaluating its mechanical durability.

Constant temperature and humidity chamber: Used for the stability testing and accelerated aging testing of the wet wipe products. By simulating the extreme storage environments such as the high temperature and high humidity and low temperature, the performance changes of the product within the shelf life and the reliability of the packaging are evaluated.