DETERMINATION OF FREE FORMALDEHYDE ON CLOTH AT LOW CONCENTRATIONS

When the AATCC Test Method 112-1978 is used to determine free formaldehyde on cloth, the accuracy and precision become progressively poorer as the level of free formaldehyde drops below 200 mu g/g (ppm). Because of the introduction of new cellulose reactants, which yield ultra-low levels of formaldehyde on cloth, a modified analytical procedure has been developed that gives accurate and reproducible results with formaldehyde content on cloth in the range of 15 to 175 mu g/g. This paper provides details f the colorimetric procedure, which is based on use of 3-methyl-2-benzothiazolinone hydrazone in lieu of the Nash reagent. No additional equipment is necessary.