Children's Swimsuit Testing

Children's swimwear testing mainly conducts scientific testing and analysis on mechanical safety performance testing, fibre composition and content analysis, formaldehyde content determination, pH value testing, decomposable carcinogenic aromatic amine dyes testing and colour fastness to chlorinated water, 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

Mechanical safety performance testing: This item mainly evaluates the physical risks that may exist during the use of the swimwear, especially the protection of children. The testing contents include the seam strength, tensile elasticity, the firmness of the straps, tapes and buckles, and whether there are accessible sharp points and edges, to prevent accidental tearing or component detachment during vigorous activities in the water, causing safety hazards such as entanglement and strangulation.

Fibre composition and content analysis: Accurately determining the fibre types and their percentage contents of the children's swimwear fabric is the basis of quality control. The testing is carried out in accordance with the relevant standards (such as the GB/T 2910 series), aiming to verify the accuracy of the product labelling and prevent the adulteration of inferior products, because the ratio of different fibres (such as nylon, spandex and polyester fibre) directly affects the elasticity, durability, comfort and subsequent colour fastness of the swimwear.

Formaldehyde content determination: Formaldehyde is commonly used for the anti-wrinkle and anti-shrinkage finishing of textiles, but it strongly irritates the human skin and respiratory tract, and may even be carcinogenic. Children's skin is more delicate and sensitive, so the free formaldehyde content in the swimwear must be strictly controlled. The test usually adopts the water extraction method, and its limit requirements are far stricter than those of adult textiles, ensuring that the product is safe and harmless.

pH value testing: The surface of human skin is weakly acidic, which is the natural protective barrier. An excessively high (alkaline) or excessively low (acidic) pH value of the textile may destroy the acid-base balance of the skin, causing discomfort such as itching and allergies. Children's swimwear needs to undergo sufficient acid-base neutralization and washing treatment, ensuring that its final pH value is within the safe range from neutral to slightly acidic.

Decomposable carcinogenic aromatic amine dyes testing: Some azo dyes will decompose and reduce under specific conditions to release aromatic amines that are carcinogenic to the human body. These hazardous substances can be absorbed by the human body through the skin. The testing adopts precise methods such as gas chromatography-mass spectrometry, strictly screening whether the swimwear fabric contains more than twenty kinds of decomposable carcinogenic aromatic amines explicitly prohibited by the national mandatory standards. This item is the safety bottom line item.

Colour fastness to chlorinated water (swimming pool water) testing: This is the key testing item that distinguishes swimwear from ordinary clothing. Simulating the environment of the residual chlorine in the swimming pool water, it examines the colour retention ability of the swimwear fabric after immersion in chlorinated water and washing. Swimwear with poor colour fastness not only has damaged appearance, but the shed dyes may also irritate the children's skin, so excellent chlorine resistance is required.

Composite colour fastness to light and perspiration testing: When children swim outdoors in summer, the swimwear is simultaneously subjected to sunlight exposure and perspiration immersion. This test simulates the composite condition, evaluates the stability of the dyes under the combined action of light and perspiration, prevents skin staining or allergies caused by colour migration or fading, and is an important indicator for evaluating the durability and safety of the swimwear.

Testing Scope

Classification by applicable age and body type: The testing of children's swimwear needs to specify its applicable age group, usually divided into infants (36 months and below), young children (3 to 6 years old) and older children (7 to 14 years old). Testing needs to consider the activity characteristics, body shape differences and risk awareness of children of different age groups, and the requirements for the design of cords and straps also become increasingly strict with the age.

Coverage of product types: The testing scope covers all swimming-specific clothing worn by children, including one-piece swimsuits, two-piece swimsuits (swim trunks, swim skirts, bikini tops, etc.), diving suits, surfing suits, and the matching swim caps and swim pants. Different styles have different testing emphasis. For example, for two-piece styles, the fixation of the top needs to be additionally considered.

Fabrics and accessories: Testing is not only aimed at the main fabric, but also includes all accessories, such as sewing threads, elastic rubber bands, adjusting buckles, zippers, hook and loop fasteners, and decorations (sequins, prints and appliqués). These parts also need to meet the safety, environmental protection and durability requirements, avoiding becoming weak links.

Extension of use scenarios: In addition to the conventional swimming pool scenarios, the testing scope also needs to consider different environments such as seaside bathing places (resistance to salt water and sunlight) and water parks (resistance to abrasion and frequent putting on and taking off), ensuring the applicability and safety of the product in multiple water-related scenarios.

Market circulation links: Testing applies to the whole chain of links such as the ex-factory inspection of production enterprises, the incoming acceptance of brand owners, the supervision spot checks of market supervision departments and the quality control review of e-commerce platforms, and is an important means to ensure the uniformly qualified quality of the children's swimwear sold in the market.

Compliance with regulations and standards: The core of the testing scope is to verify whether the product meets the mandatory regulations and standard requirements of the target markets (such as China, the EU and the United States), for example, the Chinese GB 31701 "Safety technical code for infants and children textile products" and the swimwear product standards, ensuring its legal and compliant marketing.

Testing Methods

Chemical test methods: For the chemical items such as formaldehyde, pH value, decomposable aromatic amines and heavy metals, the extraction and instrumental analysis methods specified by the standards are mainly followed. For example, the formaldehyde is determined by a spectrophotometer after water extraction or steam absorption; the pH value adopts the electrode method of the extract; and the carcinogenic aromatic amines need to be analysed qualitatively and quantitatively by GC-MS after reductive cleavage.

Physical and mechanical property test methods: Dedicated material testing machines are used. For the seam strength test, the specimen is clamped on a tensile testing machine until the seam breaks, and the maximum force is recorded. For the tensile elastic recovery rate test, the fabric is cyclically stretched to a specific elongation, and the residual deformation after recovery is measured, to evaluate the shape retention and comfort of the swimwear.

Colour fastness test methods: For the colour fastness to chlorinated water, the specimen is usually sewn with a standard adjacent fabric, placed in a sodium hypochlorite solution of a specified concentration for stirring, washing and drying, and then the change in colour and staining grades are assessed with a grey scale. For the composite colour fastness to light and perspiration, the specimen wetted with an artificial perspiration solution containing histidine is exposed under specific light equipment, and then the grades are assessed.

Cord safety assessment method: In accordance with the cord safety standards of children's clothing (such as GB/T 22702 or EN 14682), the cord length, free ends and loop circumference of the cords in specific areas of the swimwear such as the neck, back and waist are precisely measured and simulated for inspection, evaluating the snagging and entanglement risks that may occur in various states.

Small parts safety test methods: For small parts such as buttons, decorative buckles and sequins, a tension forceps is used for the tensile test (such as maintaining a 70 N tensile force for 10 seconds), checking whether they fall off or produce swallowable small parts. At the same time, a sharp edge tester and a sharp point tester are used to check whether there are mechanical hazards.

Chlorinated water durability test method: For stricter tests simulating the long-term use of the swimwear, the specimen is repeatedly immersed, washed and dried in standard chlorinated water for multiple cycles (such as 20 times), and then key properties such as the tensile elasticity and colour fastness are tested again, evaluating the service life and performance decay of the product.

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 3920-2024, Textiles — Tests for colour fastness — Colour fastness to rubbing

4. GB/T 3922-2013, Textiles — Tests for colour fastness — Colour fastness to perspiration

5. GB/T 2910, Textiles — Quantitative chemical analysis

6. GB/T 7573-2009, Textiles — Determination of pH value of aqueous extract

International Standards:

1. ISO 105, Textiles — Tests for colour fastness

2. ISO 13934-1, Textiles — Tensile properties of fabrics — Part 1: Determination of maximum force and elongation at maximum force using the strip method

3. EN 14682, Safety of children's clothing — Cords and drawstrings on children's clothing — Specifications

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): This is the core equipment for detecting decomposable carcinogenic aromatic amine dyes, certain prohibited flame retardants and volatile organic compounds. With its high separation efficiency and high sensitivity, it can carry out accurate qualitative and quantitative analysis of trace hazardous substances in complex textile extracts, and is one of the "gold standard" instruments for chemical safety testing.

UV-visible spectrophotometer: Widely used in the absorbance determination of the formaldehyde content, the pH value of the extract (needs to be equipped with a pH electrode) and some specific hazardous substances (such as extractable heavy metals). By measuring the absorption degree of the sample solution to the light of a specific wavelength and comparing with the standard curve, the concentration of the substance to be tested is calculated. The operation is relatively simple and fast.

Universal material testing machine: Used to carry out mechanical property tests such as the tensile, bursting and tearing of the swimwear fabric and seams. The equipment is equipped with high-precision sensors and multiple grips, can precisely control the tensile speed and stroke, and automatically record the force-displacement curve, thereby obtaining key data such as the breaking strength, elongation and elastic recovery rate.

Colour fastness tester series: Including washing fastness testing machines, perspiration fastness testers, light fastness test chambers (xenon arc lamps) and dedicated colour fastness to chlorinated water testing devices. These equipment can precisely simulate and control the conditions required for the tests (such as the temperature, time, solution concentration and light intensity), ensuring the reliability and comparability of the colour fastness test results.

Small parts tensile tester: Specially used to evaluate the firmness of the attached parts such as buttons, snaps and decorations on the garment. The instrument can set and maintain a constant tensile force (such as 70 N), clamp the small part with a special fixture and apply force vertically, and observe whether it falls off within the specified time, to judge whether it meets the safety requirements of infant and children's products.

Standard light source colour matching cabinet: Used for the assessment of the change in colour and staining grades in the colour fastness testing, and the consistency check of the product colour. The cabinet provides multiple standard light sources such as D65 daylight and TL84 shop light, ensuring that the raters carry out visual comparison under uniform and stable lighting conditions, reducing the rating errors caused by the light source differences.