Architects memo no. 80: June 2005
how green is green

Resene was one of the first companies to take up the challenge of NZ Environmental Choice criteria and have spent many hours and research dollars pursuing these worthwhile objectives. We still, however, get comments such as 'but you still use synthetic materials rather than natural products'.

How the word "synthetic" got such bad press completely escapes this humble scribe. A synthetic material is a product of synthesis - a means of taking some simple chemical building blocks and transforming them into more useful products. Nature is the most sophisticated of synthesisers, producing, on demand, a series of highly complex materials such as hormones and proteins within our own bodies. Nature is also responsible for the most important synthesis of all - photosynthesis, which every green plant can do; and scientists are striving to emulate.

One of the great breakthroughs in recent scientific history was the synthesis of insulin. To be able to manufacture this highly complicated molecule under controlled conditions was heralded as a great boon to mankind. The previous natural method was to extract insulin from the pancreases of bobby calves. Rumour has it that the calves were pretty pleased with the breakthrough too.

The other side of 'synthetic is bad' is that 'natural is good.' This seems to ignore the fact that Mother Nature also brings us curare, deadly nightshade, ebola, mad cow disease, necrotising fascitis and a host of other nasties.

The nub of this matter is that, at the inception of the Environmental Choice Paint Criteria, NZ was the first jurisdiction to recognise that performance of the coating could not be overlooked in assessing the environmental impact. A 'deep' green coating that had to be repainted annually must have a 10 x weighting factor against a 'mid' green coating that lasts for ten years before requiring repainting.

ECNZ insisted that paints that met its environmental criteria must also foot it in terms of performance with non-EC paints as measured by an independent testing regime.

It must be recognised that paint, by its very nature, is designed to have an impact on the environment. It is designed to prevent the bio-degradation of timber; it is designed to protect iron from natural oxidative degradation; it is designed to prevent the carbonation and slow dissolution of cementitious surfaces.

It must be further recognised that painting, and especially the surface preparation associated with repainting, is a costly and tedious business and that paint longevity has a positive economic and environmental benefit.

There can be found on the Internet (indeed what cannot be found on the Internet?) a range of recipes and references to 'deep' green paints made from a range of unlikely binders, natural earths, vegetable extracts, renewable resources, gums, balsams and various unguents. They are generally combined in a re-discovered "original" formula, which has been known to have stood the test of time!

Having watched the paint industry for some decades slowly and painfully making its technological progress towards better, more durable, cost-effective products, it would be true to say that no valuable technology would be overlooked or pooh-poohed - even the odd balsam or two. However, the arrow of progress does seem to be uni-directional and the 'deep' green paints of yesteryear do seem to be strictly for the enthusiasts and hobbyists.