The death of formaldehyde?
20 Feb 2020
Back in 2016, Formaldehyde was reclassified by the EU as a carcinogen – and it looks as though that classification will stick after Brexit. Widely known for its use in embalming, it is also used as a disinfectant in laboratories – so, do we need an alternative? John Chewins explains more…
In 2016, the EU officially adopted the reclassification of formaldehyde, under the CLP (Classification, Labelling and Packaging) Regulations EC 1272/2008, as a Class 1B carcinogen and Class 2 mutagen. In simple terms, a Class 1B identification means that formaldehyde is presumed to have carcinogenic potential in humans – i.e. it is thought to cause cancer.
Formaldehyde is a colourless, flammable gas at room temperature with a strong odour. It is used in a wide range of applications such as a chemical base for glues and adhesives, but scientists will more commonly know of its application as an organic preservative (embalming) and as a bio-decontamination agent. It is a very effective disinfectant when properly applied and has been used for decades in the decontamination of laboratories and laboratory equipment such as biological safety cabinets.
Formaldehyde disinfection cycles require long contact times and are often conducted overnight. The process also leaves a residue such as paraformaldehyde or methenamine that must be physically cleaned away. This can be difficult to accomplish in the plenums, blower modules and below work area spaces of biological safety cabinets. Although it has many disadvantages, formaldehyde remains one of the principle gaseous phase bio-decontamination agents because it is cheap and efficacious in the presence of organic soiling.
However, the reclassification of formaldehyde as a carcinogen has the potential to eliminate its use as a disinfectant agent in the laboratory sector. The Biocidal Products Regulation (BPR) is a European legislation designed to control the placing of biocidal products onto the European market, to ensure that they are safe for humans to use and do not pose an unacceptable risk to the environment. The BPR came into force in September 2013 and applies to all biocidal products. The regulation involves the analysis of a product’s performance (efficacy), toxicity, environmental fate and risk during use. The manner in which a product is intended to be used is an important factor in BPR product assessment and products must be authorised for use in accordance with specific categories called Product Types (PTs).
Biocidal products are likely to possess authorisations for a number of PTs or use areas and users should ensure that a disinfectant product or system is authorised for their specific intended use.
The reclassification of formaldehyde as a Class 1B carcinogen has profound consequences in relation to its use as a biocidal product under the BPR. Article 5 (1)(a) of the BPR states that any active substances which have been classified under EC Regulation 1272/2008 as either Class 1A or Class 1B carcinogens shall not be approved. However, under Article 5 (2) formaldehyde may gain approval as a biocide for certain limited applications, with specific conditions associated with its use. In 2015, formaldehyde was given an approval opinion for use as a biocidal active in products intended for disinfection of animal housing, animal feet, veterinary associated vehicles and eggs within a hatchery. The approval opinion states that formaldehyde application must be carried out by professionals who have adequate training. It has also been identified as a substance of concern.
Products that have characteristics that pose a particular concern to the public health or the environment are classified as substances of concern. When a product is identified as a substance of concern, it acquires another label under the BPR as a “candidate for substitution”.
Candidates for substitution are substances that the EU has determined should not be on the market and which should be phased out and replaced by more suitable alternatives over time. They can only be authorised for a period of five years, in comparison to the standard authorisation of 10 years for other biocidal products. When an active substance is identified as a candidate for substitution, products containing that active will have to undergo a comparative assessment at the time of authorisation and will only be authorised if there are no better alternatives. Formaldehyde underwent review for use in both PT2 (public area) and PT3 (veterinary); however, to date only the opinion related to its use in PT3 has been released – it is currently unknown as to whether formaldehyde will be authorised for use in PT2. Laboratory and biological safety cabinet decontamination (non-animal facility) come under the PT2 use area. If the Biocidal Products Committee (BPC) decides not to authorise formaldehyde for PT2 applications, formaldehyde fumigation within laboratories will become illegal.
In December 2017, the BPC released its long-awaited opinion on the authorisation of Formaldehyde as a biocide active substance within PT2. PT2 covers disinfectant products not intended for direct application to humans and animals – this covers the majority of disinfectant products used within laboratory and pharmaceutical areas. The BPC recommended that Formaldehyde should be approved for PT2 use.
Although the BPC recommended approval, the authorisation comes with limitations, particularly in relation to the use of Formaldehyde as a surface disinfectant delivered via the air (i.e. Formaldehyde fogging). Fogging is used extensively in research laboratories and animal research facilities as a general-purpose disinfectant. It is often used in transfer chambers to decontaminant product entering or exiting classified areas, with fogging cycles occurring multiple times per day.
So how long has Formaldehyde fogging got left?
At the moment, nobody knows. The BPC opinion has to be officially ratified by the European Commission. In June 2018, new rules governing the use of endocrine disrupting (ED) chemicals within biocides came into force. As the original BPC evaluation did not include the potential ED properties of Formaldehyde, these must be reviewed prior to the European Commission providing a final approval.
Based on the BPC PT2 opinion, users applying Formaldehyde fogging on a regular basis should take the time extension provided by the ED review to investigate and plan for the implementation of an alternative automatic airborne disinfection system.
John Chewins is an expert in the application of peroxygen based chemistries to eliminate microbiological contamination. He has worked for Bioquell for over 14 years, developing automated disinfection systems.