Formaldehyde is a volatile small molecule that is particularly used in the use of resins and adhesives. In textiles, for example, protective clothing or non-iron shirts are known to contain formaldehyde. It is proven to be carcinogenic in the respiratory tract and limited to 75 mg/kg for clothing in the EU.

Formaldehyde can be freely present in clothing, which means formaldehyde in molecular form, which can enter the environment directly (via the air or by washing). If formaldehyde is bonded, it is referred to as testing for released formaldehyde. The value for released formaldehyde is usually higher than that for free formaldehyde. Formaldehyde also occurs in wood, especially in pressboard or otherwise processed wood.

The testing for free formaldehyde including extraction is standardized according to DIN EN ISO 14184-1. CTL GmbH is accredited for this procedure. After cutting the sample to be tested, formaldehyde present in the textile is extracted with water. The extract is mixed with the so-called Nash reagent. This reacts with formaldehyde to a yellow color. The concentration in the extract can be determined photometrically and based on the weighed textile to the concentration in

mg formaldehyde per kg textile (mg/kg)

can be converted.

The process can be used for any type of fibre and any type of textile. Fibers without special equipment rarely show high levels of formaldehyde. According to the standard, the limit of quantification is 16 mg/kg, at CTL GmbH we master the test up to 5 mg/kg.