Is this the death of formaldehyde?

Formaldehyde is a common lab chemical. Widely known for its use in embalming, it is also used as a disinfectant in laboratories – however, recent EU legislation suggests we need an alternative. John Chewins explains more…  

On January 1st 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 relatively inexpensive and requires basic, simple to use application equipment

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. Formaldehyde 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 is relatively inexpensive and requires basic, simple to use application equipment. Gaseous formaldehyde can be generated by heating flake paraformaldehyde or a formalin solution in a kettle or on a heated plate. Humidity is a key parameter affecting disinfection efficacy and must be controlled, with the optimum relative humidity at 80%. 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).

There are 22 different PTs ranging from PT1 “Human hygiene” through to PT22 “Embalming fluids”. Biocidal products must be authorised for use within a specific PT to be marketed for that application. As an example, if a product is authorised solely for use in PT1 “Human hygiene” applications, it cannot be used as a disinfectant for hospital surfaces, which requires a PT2 “Public Area” authorisation. 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.

[caption id="attachment_55317" align="alignnone" width="620"] Recent EU legislation, introduced at the beginning of this year, threatens formaldehyde's use in laboratories.[/caption]

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 December 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. These applications are PT 3 applications. 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.

However, the reclassification of formaldehyde as a carcinogen has the potential to eliminate its use as a disinfectant agent in the laboratory sector

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.

The assessment and potential for the identification of formaldehyde as an unauthorised biocide has many laboratory managers concerned and eager for clarification as to whether or not it will be illegal for them to use formaldehyde for decontamination activities within their facilities. During the EU’s public consultation on alternatives to formaldehyde, hydrogen peroxide vapour (HPV) was put forward as an alternative technology in PT2 use scenarios. The response to the public consultation was predominantly in support of the use of formaldehyde in PT3 applications, where the presence of gross organic (i.e. cow sheds, chicken houses, etc contain very high levels of organic) makes the use of oxidation based biocides non-viable. This support and lack of an alternative, is likely to be the reason why formaldehyde was approved for PT3 use. The clean conditions found within laboratories are likely to mean that the “no suitable alternative” position due to the presence of high levels of organic supporting PT3 inclusion and use, will not apply to PT2. The UK Health and Safety Executive (HSE) also believe the future of formaldehyde as a biocide is looking uncertain. In the July 2015 edition of its “Biological Agents eBulletin” the HSE identified the impact of the Class 1B reclassification in relation to the authorisation of formaldehyde under the BPR. The following statement was presented in the eBulletin in bold text:

“HSE therefore recommends that users start to look into the development of alternative gaseous disinfectants for rooms and equipment, whilst there is time to do so”

The BPC’s opinion on the approval of Formaldehyde in PT2 is due in the summer of 2016 – so any time now. Laboratory, Health and Safety and Quality managers of facilities that currently use formaldehyde should be monitoring the announcements from the European Chemicals Agency and the UK HSE in relation to the status of formaldehyde. In line with the UK HSE’s 2015 recommendation, laboratories should be developing plans to move away from the use of formaldehyde as a bio-decontamination agent.

Author

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.