Painting and decorating
By using non-toxic products with low emissions, you can make your home healthier for yourself and your family.
Painting and decorating makes your home more attractive, and makes walls and other surfaces more durable, by protecting against wear and tear and the effects of exposure to the elements.
However, some ingredients in painting and decorating products may create significant environmental impacts during manufacture, could be harmful to humans during use and after application, or may create problems during disposal.
Look for products that:
- are endorsed with independent environmental labels such as Environmental Choice New Zealand
- have ingredient information readily available
- are based on natural products.
Toxicity, emissions and air quality
Paints, wall coverings, sealers and finishes are made from a variety of ingredients that can include:
- colouring agents or pigments
- plant fibres (paper, textiles)
- additives and extenders
- plasticisers (for flexibility).
Some of these ingredients can be synthetic or based on plant, mineral or animal products. Synthetic ingredients can be made from a range of chemical substances.
Before you choose a product, ask to see its material safety data sheet so you can satisfy yourself you are not exposing you or your family to toxins or allergens.
Volatile organic compounds (VOCs) are chemicals that become airborne (and therefore breathable) at room temperature. Asthma research has found a link between home exposure to VOCs and incidence of asthma in young children.
Water-based products have lower solvent emissions and are less harmful to use and dispose of. Water-based acrylic paints and finishes can still contain VOCs, so check the label for the VOC level (or the percentage of hydrocarbon solvent). To be licensed to use the Environmental Choice New Zealand label, paint must -among other things not contain more than 25% hydrocarbon solvents by weight.
Solvent-based products such as oil-based enamel paints, and some varnishes, can release significant levels of VOCs during and after application (polyurethane can give off VOCs for years). Mineral turpentine may be used as a solvent in the paint and as a paint thinner during use - it can contain benzene, which is carcinogenic.
Natural, plant-based paints and finishes can use plant oils based on citrus or tree oils and natural turpentine - these release low levels of non-toxic VOCs.
Pigments add colour and finish and can include:
- metal oxides - these provide a wide colour range, but are toxic to produce and use especially if based on mercury, lead, cadmium, or chromium
- synthetic organic pigments - these are less toxic to produce and use but may still be derived from petrochemical by-products such as phenols, benzene, toluene and xylene, all of which can be harmful to health
- naturally occurring earth and plant-based pigments.
Binders and other additives
Binders include resins, oils, and acrylic emulsions. Synthetic resins are commonly associated with emissions.
Synthetic resins are usually part of oil-based paints, (which require mineral turpentine - a common source of VOCs as the solvent) and acrylic paints in which the resin is suspended in water. Check for:
- epoxy - products using epoxy usually need solvents (like formaldehyde and toluene) and chemical additives to form durable coatings and adhesives; two-part epoxy systems can emit high levels of VOCs as they cure
- alkyd - this is a polyester or linseed oil system used for enamel paint and can cause skin or eye irritation
- polyurethane - this is produced by reaction with isocyanates and benzenes, which can cause respiratory and skin conditions; polyurethane must be handled very carefully, and may emit VOCs during and after application.
Some of these resins can be moisture-curing - which means less free solvent residue as they fully react with water. When you check the material data sheets and ingredient lists, avoid products that are classed as hazardous or dangerous.
Consider wall coverings made from inert and often-recycled materials such as polyester, and plant fibres. Textile-based wall coverings are generally more breathable and less toxic than those based on PVC. Check the VOC levels of the additives and adhesives used to install wall coverings - they can be high.
Recyclability, re-use and waste minimisation
Some regions have paint collection and recycling schemes for old and leftover paint, and there are recycled paints available. Container recycling should be possible through metals or plastics recycling, especially for environmentally labelled products. Resene runs a Paintwise programme where unwanted paint is reused and the cans recycled. Where possible, keep or give away unused paint - don't throw it away.
Some paint products may contain ingredients such as oxides that have been recovered from other manufacturing plants.
Waste minimisation and disposal
To minimise waste, only buy as much as you need. Natural paints and finishes will eventually biodegrade on disposal, but all products should be disposed of carefully. Never tip paint or solvents down a stormwater drain. It can contaminate waterways.
Wall coverings made with vinyls, latex or other synthetic material will be difficult to recycle.
The first thing to check is an ingredient list. Many paints and oils labelled as 'natural' fully declare all the product ingredients - including any references to aromatic compounds (i.e. compounds that contain or are based on benzene) that some people may find irritating.
If the ingredients are not declared, look for paints and products endorsed by independent schemes such as Environmental Choice New Zealand. Such products have low levels of VOCs and hydrocarbon solvents; and no heavy metals, formaldehyde or harmful solvents. Check the Environmental Choice NZ website for the paint specification.
A wide range of painting and decorating products is manufactured in New Zealand, to suit New Zealand conditions (especially durability to ultraviolet light). Natural paints and finishes can either be imported finished products, or imported ingredients that are on-processed locally.
To protect human health and the environment, support product suppliers using endorsed environmental management systems or who are making an effort to reduce the environmental and health impacts of their manufacturing.
Sustainability and life-cycle
Manufacture of paints, finishes and wall coverings generally involves a range of chemicals, solvents and raw materials from a variety of sources, and with toxicity levels ranging from high to zero. In New Zealand, managing these materials is regulated by the Hazardous Substances and New Organisms Act - which helps ensure the handling and processing is done safely.
As well as managing environmental impact, worker health and safety needs to be protected during manufacturing.
If the material you are considering has low or no levels of toxicity, or toxic compounds, it is likely to have less impact on the environment than one containing metals and solvents.
Natural products should be sourced from renewable, sustainably managed or recycled raw materials - some of which happens outside New Zealand. Ask your supplier for details if you aren’t sure.
Efficiency and functionality
Paints and finishes
Durability and maintenance properties are important when choosing the best paints and finishes. Coatings which last longer tend to have lower environmental footprint over the life of the house - and you won't need to repaint as often. You may want to use different products in different parts of the house. What you choose for the exterior may be decided by the climate and the required durability.
Many solvent-based and acrylic products were developed for their durability for a range of conditions, and ease of maintenance - especially when exposed to weather. However, natural products are often based on traditional formulations that have worked for decades.
Many natural paints provide good durability for inside use, as well as being more breathable and able to absorb moisture. Acrylic paints are durable, and can be easier to wash. Try samples to check the texture of the paint, as well as the colour - different ingredients provide a variety of surface finishes.
Using natural oils rather than polyurethane protects timber while allowing it to breathe. Absorbing the oil reduces water penetration, hardens the wood and helps protect from ultraviolet light - without the release of VOCs. There can be trade-offs with finishes between durability, emissions, ease of use and time between re-coats - it will depend on the surface.
If two products have similar durability properties, choose the one with the lowest VOC and the most information on its components.
These are promoted for their durability and ease of use especially in high moisture and high UV environments. They also have a range of textures and effects.
From Smarter Homes
From other sites
Ecospecifier is an Australian website with guidelines about selection of healthy building products and materials including paints and finishes.
The former Waitakere City Council's website has a series of factsheets, including:
The Building Biology and Ecology Institute's website has courses and publications on natural building materials
The Ministry for the Environment's website has a page about what to look for when choosing paints.
The Ecobob website has a directory of environmentally friendly products and services, including paints.