Understanding Class A baby socks: formaldehyde, pH and attachment safety

Baby socks are textiles in direct contact with the skin and face stricter safety requirements than adult socks. This article explains what GB 18401-2010 and GB 31701-2015 require for formaldehyde, pH, colour fastness, attachment strength and cords, and how Kaixin controls each item in production.

Why baby socks face stricter standards than adult socks

Baby socks sit directly against an infant's skin, and infants chew and pull at what they wear. National standards therefore set a higher safety class for textiles for infants and young children and bring the physical safety of decorative attachments into scope.

GB 18401-2010: basic safety specification

This standard sets limits for formaldehyde, pH, colour fastness and banned aromatic amine dyes. Baby socks must meet Class A: formaldehyde no higher than 20 mg/kg and pH between 4.0 and 7.5. Children's and adult socks must meet at least Class B: formaldehyde no higher than 75 mg/kg and pH between 4.0 and 8.5.

GB 31701-2015: safety specification for infant and children's textiles

Building on GB 18401, this standard adds requirements for heavy metals, phthalates, attachment tensile strength, attachment size, sharpness and cords, and applies to textiles for infants and children.

Kaixin's key controls for baby categories are:

Lace, bows, ribbons, lily-of-the-valley trims and bead decorations are individually pull-tested to eliminate the risk of detachment
No small parts of 3 mm or less are used, avoiding choking and ingestion hazards
Products contain no accessible sharp points or edges
No cords at the head or neck of products for infants and children under seven
Total lead and cadmium are strictly controlled and six phthalates are restricted

Eleven internal quality tests

Beyond safety parameters, socks must pass 11 internal quality tests covering formaldehyde, pH, banned aromatic amine dyes, odour, colour fastness to water, perspiration, dry rubbing and wet rubbing, fibre content and elongation (no less than 17.5 cm laterally).

How Kaixin implements it

The company runs a three-tier quality organisation with separate incoming, in-process, finished-goods and outbound inspection roles. Production follows a first-article approval rule with inspections every two hours, and finished goods complete 11 internal quality tests plus a full visual inspection before dispatch, targeting a 100% outbound pass rate.