Materials inside your home

We spend most of our lives indoors

We spend most of our lives indoors, so the interior environment is a big influence on our health. You can reduce your family's exposure to potentially harmful chemicals and improve the indoor air quality in your home through careful choices of materials, furniture and finishes.

Toxicity, emissions and air quality

Volatile organic compounds

Some materials commonly used inside your home can contain chemicals, some of which can harm your health. A major source of indoor air pollution is the release of volatile organic compounds (VOCs) from materials and furnishings.

VOCs are chemicals that become airborne and therefore breathable at room temperature. VOCs can have a range of effects on health, including irritated eyes and airways, headaches, nausea and rashes. Some VOCs are more hazardous than others – some have no known health effects, while others are highly toxic and have been linked to serious health effects like organ damage or cancer.

Volatile organic compounds' impact on indoor air quality on the United States Environmental Protection Agency website has further information on VOCs' impact on indoor air quality.

VOCs are commonly found in:

• paints
• padding made from synthetic foams for furniture
• padding made for carpets, carpet backings and underlays (some manufacturers publish VOC test certificates for their products showing which and how much VOC is emitted)
• treatments for stain-resistance and insect-resistance
• glues/adhesives
• vinyl flooring
• timber flooring on concrete
• engineered timbers such as plywood
• reconstituted wood products such as MDF and particleboard
• finishes such as polyurethane and paints
• plastic, eg wallpapers

To minimise your exposure to VOCs:

• look for carpet backings and underlay made of felt, natural latex or jute rather than foamed polyurethane.
• look for water-based or acrylic-based adhesives.
• if you're considering furniture, flooring or other surfaces made from engineered timber, or reconstituted wood products, look for products with low emissions. Any product made from engineered timbers should be covered or sealed to minimise VOC emissions. Manufacturers often advise that these products must be encapsulated.
• consider flooring options such as ceramic tiles, polished concrete, and linoleum – these have low VOC emissions. Natural timber flooring with a low-VOC or natural finish is another option.
• look for natural finishes, or finishes that are water-based or acrylic-based. Even products that appear natural – such as bamboo, wool and wood – may have finishes or adhesives that emit VOCs.
• ventilate your home multiple times each day to remove indoor pollutants and moisture, or use a whole-house ventilation system.

Painting and decorating has more information about finishes.

Ventilation has details on keeping your home healthier.

Wool scouring and dyeing

Significant amounts of metal compounds and chemicals may be used during the wool scouring and dyeing processes of carpet manufacture. While the residual levels of these compounds and chemicals may be low in the finished products, the waste streams from processing can be highly toxic to workers and waterways. Textiles using plant-based dyes are preferable.

Recyclability, reuse and waste minimisation

About half of the waste that goes to landfill in New Zealand comes from construction and demolition. By reducing waste, you're saving money and you’ll be reducing the toll on the environment.

You can reduce the amount of waste on your site by asking your designer to work with sizes which minimise the number of off-cuts. When commissioning a building company, ask them to create a waste management and recycling plan.

Recycling and safe disposal

Products made from natural materials will generally biodegrade without causing any environmental harm, provided they haven't been treated with toxic chemicals or blended with non-biodegradable synthetic materials. Textiles can generally be recycled, as can metal fittings, provided they are disassembled.

Depending on the finish and backing, pure wool carpet can be recycled or safely disposed of in landfills. If it has a natural backing it makes great weed matting.

Linoleum (as opposed to vinyl), made from linseed oil, pine resins, limestone and wood flour rendered onto a natural jute backing, can be safely composted or incinerated at the end of its life. Note that very old linoleum may have asbestos in the backing and must be removed and disposed of by a specialist removal company.

Gypsum plasterboard has good recycling potential. In some New Zealand locations – used plasterboard can be recycled to make new plasterboard or used as a compost additive. Finely ground gypsum is an excellent soil conditioner.

MDF, plywood, and treated timber cannot be recycled and should not be burnt.

Recycled synthetic materials

Some plastics (such as PET – polyethylene terephthalate from bottles) and some resins are recycled for use in furniture frames and fabrics. Some plastics used in furniture and fittings are also recycled.

Polyvinyl chloride (PVC) is used for vinyl upholstery and plastics. Recycling can be limited in New Zealand, especially if it is blended with other compounds. Some plastic components may use recycled PVC.

Upcycling old furniture

In recent years the trend has been to renovate and up-cycle existing furniture and fittings. This reduces waste and resource depletion, and reduces the potential for introducing new VOCs into your home if you're careful about selecting new paints and materials.

Older furniture is often painted with lead paint, so take extra care when refinishing it. Exposure to even small amounts of lead can result in lead poisoning and cause severe health problems, especially for children.

By wearing goggles, a dust mask and a hat (to prevent dust getting in your hair), and keeping your skin covered you can reduce the risks of exposure while removing the old paint. Anyone who has been exposed to the dust should carefully wash their hands and face before eating food. Wet sanding is helpful in reducing the amount of dust getting airborne.

Painting and decorating has more information about lead paint.

Sourcing products

Furniture, wall, floor and ceiling products come from local and imported sources. It can be difficult to be sure whether the materials are non-toxic and come from sustainable sources.

As a general guide look for:

• for wooden furniture and floor coverings look for the FSC (Forest Stewardship Council) label
• renewable or recycled materials such as bamboo, sisal, coir, jute, silk and cotton – imported and wool, possum fur, hemp and untreated wood – grown in New Zealand.
• independent environmental labels such as Eco Choice Aotearoa on products including:
  • carpets
  • floor coverings
  • plasterboard and paints
  • insulation
  • reconstituted wood panels
  • steel
  • cement
  • concrete
• evidence of environmental management practices and processes (such as ISO 14001 certification)
• wood components that are certified as coming from a sustainable source
• information about the efforts of relevant manufacturers, in relation to:
  • environmental management
  • natural area regeneration
  • minimising effects on local communities

When buying furniture and cabinetry, look for:

• sustainably sourced and recycled materials
• non-toxic finishes
• flat-packed products for efficient transporting
• ease of disassembly for reuse or disposal
• products that use a minimum amount of materials and energy in their creation.

If you're looking for furniture or cabinetry which is made from recycled timber, check the origins of the timber – some is actually made from new materials that are made to look old. This can also be the case for 'vintage' furniture.

Sustainability

Plant-based materials, including timber are used extensively in furniture, textiles and floor coverings. They offer a biodegradable and renewable alternative to non-recycled synthetic materials, but need to be produced in an environmentally friendly way to minimise the use of non-renewable resources, chemicals, and land and water pollution.

Products such as bamboo, coir (from coconut fibre), sisal, cork, jute, wool carpet and timber should be from renewable, sustainably managed sources. Linoleum also has a high level of renewable components.

Products with components from non-renewable, but plentiful, natural sources include tiles, glass, plasterboard (paper, gypsum), fibre-cement, concrete and stone/stone composites.

Vinyl products are based on non-renewable chemical compounds, as are synthetic carpets – although carpet products can have a high recycled content.

The terminology around so-called 'bio-plastics' can be confusing. If a plastic is made from a natural or renewable resource, it should be referred to as a 'bio-based plastic'. In contrast, biodegradable/compostable plastic describes a plastic that degrades quickly (depolymerizes) in a commercial composting operation at the end of its use. There are several commercially available polycaprolactone (PCL)-based blends that do meet this requirement.

The three types of bioplastic are:

• bio-based/renewable and non-biodegradable plastic
• bio-based/renewable and biodegradable plastic
• fossil-based and biodegradable plastic.

Plastics NZ has information about various plastic types.

Aluminium and steel have a high environmental impact when sourced from raw materials. However, recovery of embodied energy is high when recycling. Both aluminium and steel recycling are well established in New Zealand.

For details refer to the BRANZ Level material fact sheets

Durability and maintenance

When you are selecting materials and products, consider the lifecycle costs and impacts from manufacture through to maintenance and eventual disposal. This means looking at durability and maintenance requirements alongside the embodied carbon and environmental attributes.

Some products or materials may have a lower impact for production, but require more maintenance and/or last for less time. This could result in the lifecycle cost and/or overall environmental impact of the product being greater than an alternative product that seems less environmentally friendly to start with.

For durability, hemp fibre is a robust, long-lasting material with good resistance to ultraviolet light damage and thermal qualities. It is an effective option for upholstery and curtains. Fibre blends (wool/cotton, cotton/hemp) can also deliver durable options for textiles.

Some flooring materials may not be suitable for use in areas where it is likely to get wet, for example, laminated timber, parquet or bamboo – so check the manufacturer’s specifications.

Some hard flooring such as timber may need coating, covering or treatments to ensure durability and reduce the need for regular replacement. Linoleum is a hard-wearing and durable floor-covering that needs no extra treatment once it is laid. However, if you intend on using a floor or wall for thermal mass heat storage, remember not to cover it unless it’s with something of similar density, for example ceramic tiles are suitable, but not carpet.

Heavy materials such as concrete, stone and tiles are very durable and should need little maintenance.