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Chemicals
PVC
VOCs & Formaldehyde    
Durability & Whole Life Costing
Embodied Energy
Hygroscopicity
Reclaimed Materials
Recycling
 

Chemicals

The factors that can lead to ‘sick building syndrome’ are many and complex, but one certain influence is chemical use in materials, which can cause asthma, rhinitis, and skin conditions, amongst other diseases.
 
Chemical use has been profligate in all industries since the 1920s, however until recently (with some well known exceptions such as asbestos) much of this has been completely unregulated. Usage has undoubtedly had a damaging effect on both human health and the wider environment.
 
The Registration, Evaluation and Authorisation of Chemicals (REACH) regulation came into effect in the EU in 2007, ensuring that any chemical in widespread use has a registration dossier designed to offer a high level of protection for human and environmental health. Currently there are 151 chemicals on the authorisation list – chemicals will be withdrawn from the market unless a good case is made for their continued use. (http://goo.gl/gdf87r)
 
The SIN list (Substitute It Now) is being developed by NGOs in collaboration with enlightened private business. This currently lists 626 substances of Very High Concern – substances that cause cancer, alter DNA, damage reproductive systems, build up in nature, and have  the potential to cause serious and long-term effects. (www.sinlist.org)
 
The embargo on certain chemicals has had an effect on some building materials, however there are still over 140,000 chemicals and compounds used in everyday products, very few or which have been tested in every situation or are properly understood.
 

PVC

PVC is one such material, which from its origins in the 1830s has seen the world market grow to around 40 million tonnes - 70% for use in construction. PVC is durable and corrosion resistant, making it suitable for pipework and very popular as an ‘inexpensive’ window frame material.Thanks to the addition of plasticisers, it has also marginalised once dominant linoleum as a floor covering.
 
More recently there has been a strong reaction to the material. Before the mid-90s, questions were asked about the associations between its production and illness of workers and further research was found to support these links. 
 
More recently, Greenpeace have called for its phasing out - 'We all stand to gain as the environmental burden of toxic, persistent, bio accumulative chemicals, of hormone disrupters and of heavy metals would be significantly reduced.' (Greenpeace)
 
Whilst PVC is still widely used, in some cases (particularly in medical applications) a policy of using other polymers and materials has been implemented. 
 
After much further research, the PVC industry has admitted issues and striven to remove the toxic elements of the product and the more dangerous aspects of its production and disposal; this has done much to reduce its overall environmental impact.
 
However, the manufacture and some methods of disposal of PVC are inherently dangerous, and even if the risk of release of toxic chemicals to the environment is low, it is a risk that need not be taken.
 

VOCs & Formaldehyde 

Volatile Organic Compounds (VOCs) have a high vapour pressure (they turn to gas) at room temperature. VOCs include both synthetic and naturally occurring chemical compounds - gases are given off by materials and products that contain chemicals such as flame retardants, plasticisers, preservatives, glues, paints, and solvents. 
 
VOCs are numerous, varied, and ubiquitous – in fact most scents or odours may be regarded as VOCs. However, some VOCs are dangerous to human health or cause harm to the environment. Anthropogenic VOCs (those resulting from human activity) are regulated by law, especially indoors where high concentrations are likely to be found.
 
Harmful VOCs have long-term health effects, with symptoms slow to develop rather than being immediately toxic – this means that research into their effects is difficult. Harmful VOCs might cause irritation to the eyes, throat, skin, as well as breathing issues and psychological reactions.
 
When VOCs, nitrogen oxides, and carbon monoxide react in the atmosphere in the presence of sunlight they produce ozone – a pollutant and a constituent of smog.
 
Formaldehyde is one of the best known VOCs with negative side effects, and yet it is used widely as a bonding agent in pressed wood products (eg plywood, MDF).It is also a component of  urea-formaldehyde used in foamed insulation, as well as in shampoo, lipstick, nail polish, glues, ink, paint and wrinkle-free fabrics.
 
At room temperature it is a colourless, pungent smelling and flammable gas, created naturally as a by-product of organic combustion or atmospheric reactions, or is formed by oxidising methanol (CH2O). It is extremely reactive and is often mixed into chemical compounds to form a stable substance.
 
In the 1970s, concern was expressed about people’s exposure to formaldehyde, both in terms of workers exposure as part of their employment, and also the general public who were becoming increasingly affected as buildings became more air-tight due to the energy crisis at the time.
 
The US Environmental Protection Agency (EPA) describes formaldehyde as causing '…watery eyes, burning sensations in the eyes and throat, nausea, and difficulty in breathing in some humans exposed at elevated levels (above 0.1 parts per million). High concentrations may trigger attacks in people with asthma. There is evidence that some people can develop a sensitivity to formaldehyde. It has also been shown to cause cancer in animals and may cause cancer in humans. Health effects include eye, nose, and throat irritation; wheezing and coughing; fatigue; skin rash; severe allergic reactions.' 1
  
There  is little dispute about reactions to Formaldehyde, although it is only recently that consensus appears to be forming regarding formaldehyde as a significant carcinogen, causing leukemia, particularly myeloid leukemia, and nasopharyngeal cancer – a rare cancer of the nose.
 
The formaldehyde industry of course disputes this, saying it is “biologically implausible” - at a 2007 International Formaldehyde Science Conference organised by the European Formaldehyde Industry Association, it was resolved that '… the common use of formaldehyde in consumer products and other applications does not pose a risk to human health'. Many other agencies and associations regard formaldehyde as a harmful VOC and carcinogen.
 
Formaldehyde exposure in the home is likely to be of concern only in new builds, or homes with lots of new furniture – either way, after a year concentration reduces considerably, and ventilation until then is of prime importance.
 
To avoid any potential health problems due to VOCs, use natural products and hygroscopic materials (those that are able to absorb moisture), and avoid preservatives or synthetics – this is especially true when you’re decorating the nursery ready for the new arrival! [http://en.wikipedia.org/wiki/VOCs#Anthropogenic_sources]
 
Also, there are many indoor plants that have been proven to absorb VOCs and formaldehyde [http://en.wikipedia.org/wiki/List_of_air-filtering_plants]
 
For more information on VOCs, see VOCs and Paint.
 

Durability & Whole Life Costing

The old adage ‘you get what you pay for’ applies to building materials as well as anything – generally speaking, the more expensive a material, the less maintenance required and the longer it will last. Its replacement interval not only impacts on your pocket, but also on the wider environment, as the old needs disposing of and the new needs producing - neither costs of which are generally built into the cost of the product.
 
When choosing between different products, against cost consider:
· Durability and lifetime
· Maintenance intervals
· Performance over time
· Reusability
· Recyclability
 
For example, uPVC windows will often be fitted because they are considered cheap – but are they really? Over time ultra-violet light will cause uPVC to deteriorate, meaning that the window will only last 20 years at most, and the seals will probably have gone before then. uPVC windows cannot be mended and they cannot be recycled.
 
Timber windows may cost 3 times as much, but they are fully maintainable and should last at least 5 times longer, look better, perform better, and can be recycled at the end of their life – they also sequester CO2 and are not an oil-derived product!
 

Embodied Energy

The embodied energy of a product or material is the total amount of energy that is used to produce, distribute, use, and dispose of that product or material from ‘cradle to grave’, or even ‘cradle to cradle’. The calculations can get very complex, as everything that goes into manufacture and transportation must be accounted for, from mining the raw material to the lunches of the marketing team.
 
Embodied energy is not yet widely considered, and it has yet to play a significant part in building design or specification, but as our buildings become more efficient it will increasingly be called into question as embodied energy becomes as significant as running energy. For instance, will the refurbishment and ongoing use of an old building use more or less energy than demolishing the old building, and constructing and using a new more efficient version? Or, what’s the point of a new-fangled insulation product, if it uses more energy to produce than it’s likely to save over its lifetime?
 

Hygroscopicity

Hygroscopic materials will readily absorb available moisture from the atmosphere. They will then let the moisture out again when the atmosphere is drier. This may not sound like a good idea, but this can help greatly in maintaining a comfortable and balanced internal environment without resorting to energy intensive de-humidifiers or humidifiers!
 
Generally speaking, natural materials are hygroscopic; synthetic oil-based materials are not and often act as vapour barriers. A wall built with lime mortar, a natural insulation material, and a lime or clay-based plaster (a breathing wall) will be able to absorb moisture (and heat) when the internal environment becomes too hot and humid, and then let it out again when the internal environment cools/dries. Brick walls with cement plasters/renders/mortars are unable to do this, which can cause damp problems internally, leading to mould, mildew and potential ill-health.
 
Old breathable walls that have subsequently been treated with cement plasters/renders/mortars for the sake of ‘weather-proofing’ or ‘thermally improving’ will invariably have dampness issues and potential structural issues.
 

Reclaimed Materials

After reducing one’s consumption, the next best sustainable thing a person can do is to reuse things as much as possible.
 
Reclaimed materials inherently have a very low embodied energy as they are considered to have paid off their energy account over their last life – so their embodied energy concerns only demolition/removal from their previous role, recent transportation, and future disposal.
 
Many materials can simply be re-used as they are, and often have the added benefit of an interested timeworn quality.
 

Recycling

After Reducing and Reusing comes Recycling – many materials contain recycled elements these days, which may or may not be promoted by the manufacturer, who may not even know the percentage of recycled content.
 
You can be fairly certain that any metal will contain high quantities of recycled content, since metal does not degrade and reclaimed metals are much less expensive, having a tiny percentage of the embodied energy of new material. Due to the energy intensity of mining for example, recycled aluminium has 8,000 times less embodied energy than new aluminium.
 
Other uses of recycled content include timber into boards, crushed concrete into hardcore, crushed glass as a sand replacement, and recycled plastics as kitchen worktops or decking.
 
Recycled content differs from Recyclability however, which is concerned with how easily a material may be recycled – the two are not necessarily mutual.
 
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