A guest blog from Ian Rochester, Technical manager at the Wood Panel industries Federation
Every now and then we get asked about ‘Formaldehyde’ and mostly it’s in relation to compliance with a specific requirement or from a concerned user or specifier in relation to health impacts. In this piece I will try to explain what the current state of knowledge is and what the future is likely to be.
Formaldehyde is a naturally occurring colourless chemical composed of Hydrogen, Oxygen and Carbon. Formaldehyde is quickly broken down by sunlight and bacteria in soil and it does not accumulate in the environment. As well as occurring naturally in the environment and being essential to life, formaldehyde is also synthesised for use in manufacturing. It is a compound that provides functionality for the manufacture of plastics and polymers. One of its most common applications is as an intermediate component of some adhesive resins/binders and in this regard its use in the manufacture of wood-based panels has been widespread.
Understanding the impacts
As an intermediate compound, most of the formaldehyde used in binders is converted to other stable compounds by chemical reactions, but there can be some residual ‘free formaldehyde’ that can be emitted. It is the concentration of free formaldehyde released from products that has given rise to safety concerns over the past three decades. Over this period however research, product innovation and regulation have all helped to enhance understanding about impacts and also control. Importantly it is known that, formaldehyde has a threshold concentration below which no harm will occur. In both the workplace and in products, formaldehyde exposure can be controlled to well below those safe levels.
There is a lot of information out there on formaldehyde some scientific and some is no more than opinion (and some which is completely erroneous) which makes it difficult to form an opinion on at a glance. The World Health Organization (WHO) have made assessments (and reassessed in 2010) to provide guidance on a safe indoor air concentration for the general population and, as I write, formaldehyde is currently going through the most thorough assessment ever undertaken as part of the REACH regulation (Registration, Evaluation, Authorisation & Restriction of Chemicals). The substance evaluation process assesses all the relevant scientific information available from across the world and draws conclusions on how to manage the risks which in the case of formaldehyde will be occupational and consumer exposure limits.
From an occupational health and safety point of view, the European Commission’s Scientific Committee on Occupational Exposure Limits (SCOEL) has recommended an OEL of 0.6ppm STEL and 0.3ppm 8hr TWA*. If as expected this becomes a binding limit, then even in spite of BREXIT, it is highly probable that the current UK OEL of 2ppm will be amended
Product emissions and indoor air quality
In terms of product emissions and indoor air, in Europe there are currently two formaldehyde classes for wood-based panels, namely E1 and E2. E1 is 0.124 mg/m3 (0.1 ppm) concentration in a test chamber and E2 is an open ended class for any product higher than E1. The WHO recommended safe concentration limit in indoor air is 0.1 mg/m3 (rounded down from 0.12mg/m3) and recent studies have shown that buildings, including low energy new builds, have formaldehyde levels lower than half the WHO recommended limit. Let’s not forget, the WHO limit has a factor of safety of 5 included from where sensory irritation occurs therefore making sure it’s safe.
There is concern that the E2 class could result in an indoor air concentration higher than the WHO limit because E2 has no upper limit, this is why WPIF members and European Panel Federation member manufacturers do not produce E2 boards and haven’t done so since 2007 and many stopped making it before that. The European Commission has resisted the European wood-based panel industry’s call to remove the E2 class but until eventually removed, industry bodies should continue to insist that E2 products are not specified.
EN Standards and regulations have set the tone across Europe but elsewhere there are requirements that may vary from those in Europe that have to be met if exporting to those countries or particular certification schemes. Notably laws like CARB in California (soon to be US Federal Law), or specific scheme’s requirements like the Blue Angel, BREEAM, LEED etc… most of which approach the subject in slightly different ways.
The modernised manufacturing techniques used by manufacturers across Europe along with advances in resin development have transformed the way panels are produced such that our members can supply products that meet such demands, from zero added formaldehyde products to ultra-low emitting products that meet both the technical needs in terms of strength characteristics and that of very low formaldehyde emissions.
*ppm = Parts Per Million
STEL = Short Term Exposure Limit
TWA = Time Weighted Average
Wood Panel industries Federation