When specifying paint, architects must be aware of the sustainability issues around its manufacture and use, as well as the steps being taken to improve its environmental performance. This CPD module is sponsored by Dulux Trade
Holiday provider Natural Retreats chose Dulux Trade’s Ecosure Matt and Ecosure Quick Drying Eggshell paints for the refurbishment of 20 eco-homes in the Yorkshire Dales.
How to take this module
To take this module read the technical article below and click through to a multiple-choice questionnaire, once taken you will receive your results and if you successfully pass you will be issued automatically with a certificate to print for your records.
Assessing the environmental impact of paint is a complex and multi-faceted issue. Many of its constituent materials derive from fossil fuels or involve an energy-intensive production process. Solvent-based paints also often contain high levels of volatile organic compounds (VOCs), which contribute to air pollution. Paint also creates a number of waste issues: tins caked in paint residue are difficult to recycle, and cleaning brushes can contaminate the water supply.
But paint also offers many environmental benefits. A report by sustainable development organisation Forum for the Future, in collaboration with paint manufacturer AkzoNobel
and construction company Carillion, points out that painting a surface can extend its lifetime and that redecorating can be a far less energy-intensive alternative to rebuilding. Painting in light colours can also reduce the need for electric lighting.
Partly as a result of the report, which was titled Identification, Design and Delivery of Zero Emissions Paint Systems, paint companies such as Dulux Trade have renewed their focus on improving the sustainability of their products, not only the materials and processes used in manufacture, but also in terms of packaging, lifecycle costs and accurate carbon footprint analysis.
Manufacture and performance
In terms of a paint product itself, there are three key factors that need to be considered when assessing its sustainability: how long it lasts, how much you need and what is in it.
Paint is made up of a number of ingredients. Pigments such as titanium dioxide, clays or chalks give the paint its opacity, toughness and texture; a binder, often a type of acrylic, holds the pigment together; solvents such as white spirit influence the viscosity and spread of paint, as well as how it dries; and various additives can be used to modify properties such as surface tension and freezing point.
Analysis carried out by the Forum for the Future project assessed the contribution of each of these components to climate change. This found that pigments were by far the biggest factor, contributing 56% of the paint’s emissions. This is because they are very energy-intensive to produce: the impact of the extraction and processing of resources that go into making paint can be as much as 10 times higher than the impact of paint production.
Binders were another significant contributor to carbon emissions (9%) as they are based on fossil fuels. Solvents contribute 3% but are also the main source of VOCs, which are a major air pollutant as they react with nitrogen oxides to form ozone and photochemical smog.
One of the key areas in which manufacturers are improving the environmental performance of paint is in reducing the levels of VOCs. EU directive 2004/42/EC, which was incorporated into UK legislation in 2010, has imposed strict VOC limits on paints. As a result, research and development in water-based products has increased, leading to improved formulations with greater opacity (or coverage), improved whiteness and better adhesion.
Durability and efficacy
However, the various emissions of paint should not be considered in isolation. As the Forum for the Future report points out: “The efficacy and durability of paint means that relatively high-emission paints with high durability may sometimes be a better choice than low emission paints with poor durability.”
Redecorating twice as opposed to five times over a 10-year period can clearly help reduce the carbon footprint in a number of ways, for example:
- Decorators burn less fuel to get to and from site and consume less electricity while they work.
- Less paint needs to be manufactured and transported.
- Applying fewer coats over the decade means that fewer VOCs are released into the environment.
Similarly, products that have a higher opacity or spreading rate may have a smaller overall environmental impact, even if they have a higher impact per coat. In order to get a full picture of a product’s environmental impact, it is vital for manufacturers to use detailed assessment tools (see box opposite).
Waste and water
The materials used in the paint itself are not the only factors that contribute to its sustainability performance. Waste is a major issue in the paint industry, and one that has come sharply into focus with recent increases in landfill taxes and the introduction in 2008 of a legal requirement to provide site waste management plans (SWMPs) on construction projects over £300,000.
Solvent-based paint cannot be recycled, but it can be used as a fuel to generate power
The can itself accounts for about 10-20% of the total environmental footprint of a can of paint (depending mainly on the type of paint being used).
Traditionally most cans go to landfill because there are few viable recycling options. This is due to the fact that leftover paint residue is hard to remove from the packaging material. It can also contaminate otherwise recyclable materials.
A further direct impact of waste paint is on the water supply. The Forum for the Future report states that each time a brush or roller is cleaned, it uses — and contaminates — an estimated 25-150 litres of water. If this water is released into the drains it will have a major environmental impact as solvent-borne paints are considered a hazardous substance.
However, a number of initiatives are helping to combat these waste and water issues.
Takeback services, such as the Dulux Decorator Centre scheme, allow painters to return cans that may have a small amount of residual paint inside. These are consolidated and taken to a recycling centre, where the metal cans can be separated from their solvent-based paints and recycled into new metal products.
Solvent-based paint cannot be recycled, but it can be used as a fuel to generate power or fuel another process. The plastic cans, on the other hand, are separated into empty plastic cans and water-based paint. The plastic containers can be recycled into new plastic products and the paint can be composted.
Other innovations include changes to the cans themselves. Simple design changes have helped reduce the weight of the can, saving materials. For example, Dulux Trade’s 10-litre plastic can is now 13% lighter than previous designs and the 2.5-litre can is 7% lighter.
Another improvement is the development of a “ringless” can, designed to make recycling easier. The inner ring was originally developed to add structural strength, but it trapped paint residues. Removing this makes it easier to clean cans for recycling.
Dulux Trade launched the Environmental Wash System in the UK market in 2008 to address the problems with water consumption and contamination. It is a mobile cleaning station that uses water to wash brushes, rollers and equipment, then separates it into solid waste and clean water. This prevents contaminated water being released into the drains.
The Forum for the Future scheme also pioneered the Closed-loop Water Project, which takes the water used to clean production equipment between the manufacture of different paints, and uses it in the next batch of paints. It is estimated to save at least 2,600 tonnes of water at one manufacturing site alone.
Assessing environmental performance
With so many different aspects to a product’s environmental footprint, data-intensive lifecycle analysis is essential to gain an accurate picture of its sustainability performance.
Unfortunately, one of the construction industry’s main tools for finding out materials’ lifecycle performance, the BRE’s Green Guide to Specification, does not list paints.
Other assessment systems cover paint in various levels of detail. These include:
- Breeam, which covers VOC levels but only addresses paint in a very general way.
- LEED, which measures VOC content in a different way to Breeam and has limited uptake in the UK.
Forum for the Future has also developed the Environmental Impact Analyser (EIA) — a tool that measures the embodied carbon, water, waste and VOCs of different paints.
The EIA assesses these impacts at each stage of the paint lifecycle, from the extraction and processing of raw materials, through manufacture and transportation, to the recycling of paint cans.
This allows manufacturers to measure and compare the precise impact of different ingredients and processes, and to assess characteristics such as durability or opacity against their emissions levels.
BD’s free continuing professional development distance learning programme is open to everyone who wants to develop and improve their professional knowledge.
These modules can contribute to your annual CPD activity and help you maintain membership of professional institutions and bodies.
This module will contribute 1 hour towards your CPD obligations. If successfully completed, certificates will be distributed two weeks after the module closes.
Duration: 1 hour
Module 14 Deadline: August 16 2013
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