Formaldehyde reclassified

Considering the labelling of substances containing formaldehyde in line with recent regulatory changes.

by David Merrell

With the chemical formula CH₂O, formaldehyde (also called 'methanal'), is the simplest of the chemical group of aldehydes. In its natural form, formaldehyde is colourless gaseous compound having a distinctive pungent odour. It is most commonly used in industry as a saturated solution containing approximately 37 per cent formaldehyde by mass (40 per cent by volume) in water – a solution that may also be referred to as '100 per cent formalin'.

In June 2014, regulation 605/2014 concerning the classification, labelling and packaging of substances and mixtures (the CLP) was updated, and one of the chemicals that was reclassified was formaldehyde. As a direct result, any substances or mixtures which had already been placed on the market needed to be repackaged on or before 31st December 2015 to indicate that the mixture had been classified as a category 1B carcinogen at formaldehyde levels of greater than 0.1 per cent, and a category 2 mutagen where the formaldehyde level is greater than 1 per cent. This legislation is only concerned with labelling and packaging of substances, and therefore does not affect any articles which contain formaldehyde.

In high concentrations, formaldehyde has been classified as toxic by ingestion, inhalation or skin contact, and capable of causing severe skin burns or damage to the eyes. In addition, it is believed that formaldehyde is a common allergen, with some people being very sensitive – even at low concentrations.

Formaldehyde can be used as a preservative, especially for natural textiles. In addition, within the textile industry it can be used as a finish to make textiles crease resistant. In the past, it was used as a biocide. Additionally, when reacted with phenol, urea or melamine, formaldehyde forms resins which are commonly used as adhesives within the manufacture of plywood or carpeting.

The CLP defines a carcinogen as 'a substance or mixture of substances which induce cancer or increase its incidence. Substances which have induced benign and malignant tumours in well-performed experimental studies on animals are also considered to be presumed or suspected human carcinogens, unless there is strong evidence that the mechanism of tumour formation is not relevant for humans'.

Formaldehyde is classified as a category 1B carcinogen, meaning that it is suspected to be carcinogenic to humans. For labelling purposes, mixtures which contain formaldehyde must be labelled with the hazard statement 'H350 – may cause cancer by inhalation'. Additionally, as a category 1 carcinogen, the use of formaldehyde falls within the 'Carcinogens Directive in EU Workplaces'. Directive number 2004/37/EC requires employers to minimise the risk to their employees by reducing exposure to carcinogenic substances.

A mutagen is defined within the CLP as 'a substance which causes a permanent change in the amount or structure of the genetic material in a cell, this both to heritable genetic changes that may be manifested at the phenotypic (the biochemical characteristics of an organism, as determined by its genetic makeup) level, and to the underlying DNA'. Consequently, the CLP requires packaging to carry the hazard statement 'H341 – Suspected of causing genetic defects'.

Formaldehyde is frequently included on retailer restricted substance policy lists, although not included on the REACH candidate list. However, in view of these reclassifications, this may change in the future.

Testing for formaldehyde

SATRA has a wide range of analytical techniques which enable us to determine the concentration on a range of materials, including leather, textile and wood. EN ISO 14184-1:2011 – 'Textiles – Determination of formaldehyde – Part 1: Free and hydrolysed formaldehyde (water extraction method)' determines the amount of free formaldehyde (able to be washed from the surface of the sample by water), as well as that removable from a textile by the action of hydrolysis – long-term degradation by moisture.

The formaldehyde is extracted from the sample using a water extraction procedure, before undergoing a reaction with acetylacetone reagent to enable the formaldehyde content to be measured colourimetrically (assessing the intensity of colour to ascertain the concentration). The procedure described in EN ISO 14184-2:2011 – 'Textiles – Determination of formaldehyde – Part 2: Released formaldehyde (vapour absorption method)' is similar, but the formaldehyde is extracted from the sample by the action of water vapour. This is because the sample is suspended above water in a heated and sealed vessel, to measure the level of released formaldehyde. EN ISO 17226-1:2008 – 'Leather – Chemical determination of formaldehyde content – Part 1: Method using high performance liquid chromatography' determines the amount of formaldehyde, which is extracted from leather samples using a mild detergent solution. Quantification is then measured by high-performance liquid chromatography (HPLC).

EN ISO 17226-2:2008 – 'Leather – Chemical determination of formaldehyde content – Part 2: Method using colorimetric analysis' also determines the amount of formaldehyde which is extracted from leather samples using a mild detergent solution, but quantification is determined using the same colourimetric technique as in EN ISO 14184. Analysis by HPLC is the preferred method, as any colour extracted from the sample may interfere with colourimetric analysis, meaning that the same result may not be achieved from these two tests.

Publishing Data

This article was originally published on page 42 of the September 2016 issue of SATRA Bulletin.

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