Infant and Toddler Textile Testing

Infant and children textile inspection mainly conducts scientific testing and analysis on formaldehyde content testing, pH value testing, decomposable carcinogenic aromatic amine dye testing, colour fastness testing, heavy metal content testing and phthalate 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

Formaldehyde content testing: Formaldehyde is an auxiliary agent commonly used in the textile finishing, and strongly irritates the respiratory tract and skin of infants, and may even be carcinogenic. The testing is based on the GB 31701 and GB/T 2912.1 standards. The water extraction method is used to simulate the human perspiration environment, and the formaldehyde content in the extract is determined by the acetylacetone spectrophotometric method. Its limit value requirement is extremely strict, usually ≤20 mg/kg.

pH value testing: The textile will retain the acid and alkali substances during the dyeing and finishing processes. The skin barrier function of infants is weak, and an excessively high or low pH value will destroy the weakly acidic protective layer on the skin surface, causing skin itching or allergies. In accordance with the GB/T 7573 standard, the textile is extracted with deionized water, and then the acidity and alkalinity of the extract are precisely measured with a pH meter. The standard requires the pH value to be within the range of 4.0 to 7.5.

Decomposable carcinogenic aromatic amine dye testing: Some azo dyes can be reductively decomposed to release 24 kinds of carcinogenic aromatic amines prohibited by the regulations under specific conditions. These substances are absorbed by the human body through the skin contact, with potential carcinogenic risks. In accordance with the GB/T 17592 and GB/T 23344 standards, a gas chromatography-mass spectrometer (GC-MS) is used for the qualitative and quantitative analysis. It is a mandatory testing item for the safety of the infant and children textiles.

Colour fastness testing: Mainly including the colour fastness to saliva, perspiration, rubbing and washing. Infants are prone to drooling and sweating, and often bite the clothes. If the dyes fall off and are swallowed or stain the skin, it will bring safety hazards. For example, the colour fastness to saliva is a characteristic item of the infant and children textiles, simulating the saliva environment to test the degree of the dye shedding, and the grade is usually required to be not lower than grade 3-4.

Heavy metal content testing: The extractable heavy metals such as lead, cadmium, mercury, arsenic, chromium and copper are detected. These heavy metals may originate from the dyes, auxiliary agents or processing pollution, and enter the bodies of infants through the skin contact or biting, causing damage to the nervous and hematopoietic systems. In accordance with the standards such as GB/T 30157, high-sensitivity detection is carried out with equipment such as the inductively coupled plasma mass spectrometer (ICP-MS).

Phthalate testing: As plasticizers, the phthalates may exist in the printing, coating or plastic accessories of the textile. This kind of substance has an estrogen-like effect and interferes with the endocrine system of infants. In accordance with the GB 31701 and GB/T 20388 standards, the detection is carried out with a gas chromatography-mass spectrometer (GC-MS), and there are strict limit requirements for the accessible plastic parts.

Burning performance testing: The activity ability of infants is limited. Once contacting the fire source, the burning speed of the clothes will directly affect the degree of injury. In accordance with the GB 31701 and the relevant method standards, the afterflame time, afterglow time and damaged length of the fabric after ignition are tested under specific conditions, and the infant and children textiles are required to reach the normal burning performance grade.

Testing Scope

Garment products: Including the underwear, outerwear, bodysuits, pyjamas, socks, hats and bibs and all the clothes in direct contact with or possibly contacting the skin of infants. This type of products needs to comprehensively examine the chemical safety, physical and mechanical safety and label marking, and is the key field of the testing.

Home textiles: Covering the bed sheets, quilt covers, pillowcases, blankets, towels and bath towels and sleeping bags used by infants. In addition to the conventional safety items, special attention needs to be paid to the safety of the fillings, air permeability and the possible risks of the small parts.

Nursing and carrying products: Such as the textile parts of the diapers, bibs, baby carriers, waist stools, the textile seat cushions and canopies in the prams. These products have a long contact time with infants, and have additional requirements for the abrasion resistance, colour fastness and structural safety (such as cords and small parts).

Textiles for toys: Referring to the textile components attached to the toys, such as the clothes of the cloth dolls and the surface fabrics of the plush toys. Their testing needs to simultaneously consider the relevant requirements of GB 31701 "Safety technical code for infants and children textile products" and the GB 6675 "Toys safety" standard series.

Definition of the age and height range: According to GB 31701, the infant and children textiles refer to the textile products worn or used by the infants aged 36 months and below or with a height of 100 cm and below. This definition is the core prerequisite of the applicable standards, testing items and judgement basis of the product.

Product parts and accessories: The testing is not only for the main fabric, but also covers all the subsidiary parts, such as the buttons, zippers, webbings, decorations (sequins and beads), embroidery threads and trademark labels. These parts need to be separately examined for their chemical safety, physical and mechanical safety and adhesion firmness.

Different processes and materials: Covering the different weaving processes such as the woven, knitted and nonwoven, and the various fibre materials such as cotton, flax, silk, wool and chemical fibres. Different materials and processes may introduce specific risk substances, and the testing schemes need to be targeted.

Testing Methods

Chemical testing methods: Mainly including the chromatography, spectroscopy and titration methods. For example, the formaldehyde content adopts the water extraction-acetylacetone spectrophotometric method; the prohibited azo dyes adopt the reductive cleavage-gas chromatography mass spectrometry method; and the pH value adopts the water extraction-potentiometric determination method. These methods have high sensitivity, high accuracy and good reproducibility.

Physical property testing methods: Mainly simulating the force conditions in the actual use. For example, the tensile strength testing uses a constant-rate-of-extension (CRE) testing machine; the bursting strength uses the ball bursting method or the pneumatic method; the abrasion resistance uses a Martindale abrasion tester; and the pilling is rated by comparison with the standard photos after friction under specific conditions.

Colour fastness test methods: Mostly the comparative tests in the simulated environments. For the colour fastness to saliva and perspiration, the specimen is attached to the standard adjacent fabric, treated in the test solution containing the specific components, and then the change in colour of the specimen and the staining grade of the adjacent fabric are respectively rated. For the colour fastness to rubbing, the standard rubbing cloths in the dry and wet states are used for reciprocating friction under a certain pressure, rating the staining grade.

Burning performance test methods: The corresponding methods are selected according to the product types. For example, the vertical method is commonly used for the garments, determining the burning behaviour of the fabric after contact with the flame in a vertical state; for the textiles for toys, the small flame source test method of the toy standards may be referenced. The testing needs to be carried out in the laboratory environment with the standard temperature and humidity.

Small parts and cord safety evaluation methods: The measurement and simulation tests are carried out according to the specific provisions in the standards. For example, a tensile force gauge is used to test the attachment strength of the small parts (buttons and decorations); the length of the cords and whether the free ends are knotted are measured; and whether the slip clasps are easy to slide to form a running noose is evaluated.

Sampling and specimen preparation methods: The sampling needs to be representative, avoiding the selvedges and the obvious defects. The chemical test samples need to be cut and mixed evenly; the physical test samples need to be cut according to the specified warp and weft directions or straight and transverse directions, and conditioned to equilibrium in the standard atmosphere for at least 24 hours, to ensure the comparability of the results.

Combination of the instrumental analysis and sensory inspection: The testing process is the combination of the objective instrumental analysis and the subjective sensory inspection. For example, the colour fastness rating, appearance defect inspection and pilling rating need to be carried out by the trained inspectors under a standard light source cabinet (D65 light source), comparing and judging with the standard scales or photos.

Testing Standards

Domestic Standards:

1. GB 31701, Safety technical code for infants and children textile products

2. GB 18401-2010, National general safety technical code for textile products

3. GB/T 2912.1, Textiles — Determination of formaldehyde — Part 1: Free and hydrolysed formaldehyde (water extraction method)

4. GB/T 7573, Textiles — Determination of pH of the aqueous extract

5. GB/T 17592, Textiles — Determination of prohibited azo dyes

6. GB/T 20388, Textiles — Determination of phthalates

International Standards:

1. ISO 105, Textiles — Tests for colour fastness

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

Gas chromatography-mass spectrometer (GC-MS): It is the "gold standard" equipment for detecting the organic hazardous substances such as the decomposable carcinogenic aromatic amine dyes, phthalates and pesticide residues. It utilizes the high separation ability of the chromatography and the high identification ability of the mass spectrometry, and can carry out the qualitative and quantitative analysis of the trace target substances in the complex matrices.

Inductively coupled plasma mass spectrometer (ICP-MS): The main equipment for the trace and ultra-trace heavy metal element analysis, such as detecting lead, cadmium, mercury and arsenic. Its sensitivity is extremely high, and the detection limit can reach the ppb (parts per billion) level or even lower, and it can accurately evaluate the potential risks of the extractable heavy metals in the textile.

UV-visible spectrophotometer: Used for the quantitative analysis of the items such as the formaldehyde content and heavy metals (hexavalent chromium). Based on the Lambert-Beer law, the concentration is determined by measuring the absorbance of the measured substance at a specific wavelength. The equipment is relatively simple to operate, and is the conventional configuration of the chemical laboratories.

pH meter and constant temperature water bath oscillator: The core equipment combination of the pH value testing. The constant temperature water bath oscillator is used to carry out the water extraction of the textile specimen at the specified temperature and time. Then a strictly calibrated precision pH meter is used to measure the pH value of the extract, ensuring the accurate and reliable data.

Universal material testing machine: Used to test the mechanical physical indicators of the textile such as the tensile strength, bursting strength and seam performance. This equipment can precisely control the tensile speed, record the force-displacement curve in real time, and thereby obtain the key data such as the breaking strength and elongation at break.

Colour fastness tester series: Including the rubbing fastness tester, perspiration/saliva fastness test frame and washing fastness testing machine and other dedicated equipment. These instruments can standardize the test conditions such as the pressure, stroke, temperature and solution composition, ensuring the comparability of the test results between different laboratories.

Standard light source colour matching cabinet: Provides a stable, uniform and glare-free standard light source environment (commonly the D65 daylight source) for all the items involving the colour judgement (such as the colour fastness rating and colour difference evaluation). This is the key equipment for avoiding the subjective judgement errors caused by the lighting condition differences.