Timber treatments
There are increasing concerns about the indoor air quality in our homes resulting from the wide range of synthetic chemicals in both building components and furnishings. Many of these are known to ‘offgas’, significantly affecting air quality. Not only are many of the individual chemicals a concern for our long term health, but there is a lot of evidence that they can be much more toxic in combination. Conventional timber window frames are both treated with fungicides to reduce the risk of frames rotting, as well as including more fungicides in the paint or stain finish.
The Ecoplus range of windows & doors is different and is designed to help reduce these problems. Ecoplus timber windows and doors are preservative-treated with inorganic boron salts. Although this is a highly contentious subject, boron salts are considered by many (including ourselves) to be among the safest and most environmentally benign solutions currently available to timber preservation.. The range is painted or
stained with OSMO finishes which are manufactured from plant oils and contain
absolutely no fungicides. In fact they
are so safe they are approved for use on children’s toys.
Ecoplus was launched in 1995 to
systematically address the environmental issues relating to window manufacture
including the health and environmental implications of conventional timber
preservatives. Green Building Store Directors Chris Herring and Steve Slator
had both experienced health problems after working with treated timber, and
undertook extensive research into the health and environmental effects of
conventional timber preservatives, culminating in an articlein Building for the Future magazine.
As a result of this research, Green Building Store’s Ecoplus range pioneered
the use of safer boron-based preservatives in window manufacture in the
What is boron?
Boron is an element, which forms compounds many of which are naturally as minerals. Some boron compounds - principally inorganic borates - are very effective at preventing or eradicating fungal and insect attack in timber. Inorganic borates offer an exceptionally effective answer to all those concerned about the health and environmental impact of conventional timber preservation.
Boron safety
Boron is ubiquitous at low levels in the environment, and unlike other timber
preservatives, is an essential micronutrient for animal and plant life, being
required in the human diet at approximately 1-3 mg per day. The toxicity to
humans is slightly less than that of common table salt, while the plant and
aquatic toxicity is also very low.
Boron effectiveness
Boron compounds are effective against all of the commonly known timber rotting fungi. They are also the only group of preservatives capable of eradicating dry rot (Merulius Lacrymans) in situ. More toxic timber preservatives are incapable of doing this. Boron compounds are also effective against all common causes of insect attack in timber (including termites!).
Preservative penetration
Conventional timber treatments typically penetrate to a depth of little more
than 5mm, leaving the remainder of the timber vulnerable to attack,
particularly should water penetrate beyond the treated layer.
Boron works quite differently. In a similar way to conventional treatments, our
boron treatment penetrates into the surface layers of the timber. However, the difference is that if the timber
should become damp for any reason (with consequential risk of fungal attack),
boron is mobile and will follow the moisture gradient, moving to the area of greatest risk, helping to protect the
timber. Conventional treatments do not do this.
Conventional timber preservatives
Over the last 50 years some extremely toxic chemicals have been
introduced into our homes and buildings in the cause of timber treatment. DDT,
Dieldrin, Pentachloraphenol, Lindane, Tributyl tin oxide and Arsenic are some
of the highly toxic and carcinogenic chemicals which have been used to eradicate
or prevent fungal and insect attack. Their existence in our homes continues to
put our health at risk.
The new generation of timber preservatives which came into regular use during
the late 1990s include Permethrin, organic zinc compounds, IPBC, Dichlofluanid,
Propiconazole. They are all much less
toxic than the earlier treatments, but there continue to be concerns about
their effect on indoor air quality and our health.
- German studies suggest that Permethrin, one of the most common insecticides, is a carcinogen; it is also thought to be an endocrine disruptor, and has been implicated in reproductive system disruption in animals.
- The big problem with many of these chemicals is that they slowly 'off-gas' out of the timber, yet little research has been undertaken on chronic very low level exposure in the home, or of the possible synergistic effect in combination with other chemicals present in the home. The licensing of these treatments takes no account of synergy at very low levels between different chemicals in the home.
- Some of these treatments require light organic solvents as carriers; these are implicated in health problems, and contribute to global warming.