The Sourceable written recently by Justin McGar is interesting from various points of view.
A recent Sourceable article entitled The ‘Lonely Fight’ for Green Building Material Transparency is interesting from various points of view.
Its subject matter relates to my article in January which talks about the growing movement for product constituent transparency within the various local and global green building rating tools and interestingly about water quality issues arising from potential degradation products from some plastic pipes.
Firstly, quoting from my earlier article, the way product transparency is dealt with by current overseas programs like Health Product Declaration (HPD), Declare and LEED and various ‘boutique’ lists developed by individual architectural practices like Perkins and Wills:
…fails to recognise that just knowing what is in a product is just the tip of the iceberg. Schemes such as HPD and Declare assume that people will know what to do with the information when they receive it. The HPD program does not have a defined list of banned or ‘Red List’ products Living Building Challenge, Perkins and Wills and others do, but they all seem to assume that somehow the industry as a whole is going to learn how to assess the information and apply the extremely complex knowledge and nomenclature of toxicity to their everyday practice in specifying products.
The actual need in the industry is for assessment rather than transparency. Why should the whole industry have to become experts at interpreting health and toxicity information? Once you get past the black and white "ban these really terrible compounds" scenario (this is simple to check), there are tens of thousands of grey area compounds, the safety or non-safety of which boil down to degree of toxicity, concentrations, exposures and indeed risk. The ‘good or bad’ scenario is just way too simplistic. Expecting the average designer or specifier to understand the complexity that toxicity hazard potential is a function of both dose and exposure is fine conceptually. But does every green professional need to understand this complexity?
There is no doubt that there are some chemicals that should be banned from any products, notably the persistent organic pollutants agreed within the Rotterdam Convention. There are also reasons to ban substances with proven risks, such as carcinogens, mutagens and endocrine disruptors from certain product uses and contexts, but note the qualification. Herein lies a substantial inconsistency with a ‘ban the hazard’ approach to toxicity.
Toxicity hazard is exposure and risk relative. Hundreds of even ‘natural’ and ‘organic’ compounds are carcinogenic (e.g. basil oil) or endocrine disruptors (e.g. lavender) when used neat at highly purified, essential oil concentrations, but we can use them totally safely when diluted to the recommended levels. The professional shorthand that recognises this is reflected by the equation Hazard = Risk x Exposure. You can’t make valid decisions based on hazard alone and risk needs to be assessed by considering exposure at all life stages of the product.
Herein lies the heart of the point the article mentioned earlier raises. The ‘in use’ phase of a product's impact is another important complexity that none of these schemes address.
When looking at the constituents of a product, you are not able to tell what interactions there may be between the components or with other compounds it might come into contact with during its lifespan. A risk assessment needs to be undertaken including a review of relevant literature and the standards need to be able to be flexible enough to be able to incorporate leading edge research as the basis for certification. Traditional hazard alone based approaches to toxicity in Standards used by the vast majority of ecolabels cannot do this.
The Green Building Council of Australia’s (GBCA) Green Star Design and As Built (D&AB) rating tool’s Product Transparency and Sustainability credit is currently one of only a few schemes globally to confront this massive inconsistency in the logic of how product transparency is currently being dealt with by most green building rating tools. The D&AB rating tool has recognised specific third party certification schemes to represent and review the impacts of product constituents in Base Building products including GECA, Global GreenTag, AFRDI’s Green Tick and the Carpet Institute’s ECS.
These all qualify toxics according to various approaches but the only scheme that actually uses a whole of life, Hazard = Risk x Exposure toxicity assessment that also assesses known interactions and degradation products is Global GreenTag. This is one reason is it currently under assessment by other GBCs including USGBC for LEED v4 recognition under its Product Transparency credit .
Achieving healthy product outcomes in the world of chemical based products is not black and white, but it is achievable with a whole of life, risk based approach to toxicity.