Formaldehyde Limits How It Changes with Construction and Elastane Content
Formaldehyde Limits does not stay constant when construction changes. Understanding the direction of change helps during development.
Effect of knit structure
Loop length and density move results first, usually before any yarn change is made. Working figures for Formaldehyde Limits normally sit around below 75 ppm for skin contact in mainstream production. Note ISO 14184-1 determination on the tech pack so nobody tests against an older revision.
Effect of elastane content
More elastane raises recovery but changes the value measured by ISO 14184-1 determination, so retest after any blending change. Record elastane content alongside Formaldehyde Limits, because blends shift the measured value. A result outside below 75 ppm for skin contact usually points to process drift rather than to the fibre itself.
Effect of finishing
Heat setting and softeners shift results, which explains differences between a hand sample and bulk. Keeping reference values for Formaldehyde Limits lets suppliers quote without extra sampling rounds. Ask for conditioning details together with ISO 14184-1 determination, since both affect the reading.
Typical range
Working values stay around below 75 ppm for skin contact for mainstream activewear. Working figures for Formaldehyde Limits normally sit around below 75 ppm for skin contact in mainstream production. Note ISO 14184-1 determination on the tech pack so nobody tests against an older revision.
Development advice
Change one variable at a time, then verify against ISO 14184-1 determination before moving to the next sample round. Record elastane content alongside Formaldehyde Limits, because blends shift the measured value. A result outside below 75 ppm for skin contact usually points to process drift rather than to the fibre itself.
