Formaldehyde II, quantitative determination of free formaldehyde (SOP 4193)
DIN EN ISO 14184-1 specifies a method by which free formaldehyde in textiles is extracted with water and the concentration is then determined photometrically.
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.
Since formaldehyde is volatile, a sample should be tightly packed without air entrapment. Otherwise, the measured value can fluctuate considerably.
At the beginning, we clarify the scope of testing, the goal of the tests and, if applicable, the project requirements with the customer.
We prepare a quotation based on the scope of testing and the requirements
The order is clear and as soon as the test sample is received in the laboratory, we get straight to work with the sample.
The results are available in the form of a test report. In addition to the pure test result, an overall assessment according to legal, general or customer-specific requirements is possible.
INDEPENDENT MATERIAL TESTING
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CTL® Bielefeld
Chemisch-Technologisches Laboratorium
Krackser Str. 12
33659 Bielefeld
Deutschland
Tel. +49 521 400 82 89 0
E-Mail sekretariat@ctl-mails.de