By
Quynh Nguyen

Plywood is wood engineered to be strong and flexible. Making plywood is a good way to reduce wood waste as a higher percentage of wood from a log can be used. However, the chemicals used in glues that necessitate plywood formation are a cause for concern. So we had to ask: How sustainable is it to buy products made out of plywood?

The sustainability of plywood depends on its components: wood and glues. Using wood benefits the environment because trees uptake carbon and mitigate climate change. But, because of synthetic glues, plywood is not biodegradable and has no carbon-offset value. Also, some glues emit toxic gases.

In this article, we’ll walk you through the life-cycle of plywood used for furniture and flooring. Then, we evaluate its sustainability, potential, and shortfalls. And in the end, we’ll show you tips for buying sustainable plywood.

Here’s How Sustainable Plywood Is

Plywood could be made and consumed sustainably if manufacturers source environmentally friendly components (wood and glues) and consumers arrange to recycle plywood properly. Wood is generally a sustainable material thanks to timber trees’ carbon sequestration potential. The use of natural-based adhesives containing fewer toxic chemicals causes less harm to the environment. 

“Sustainable: The ability to be maintained at a certain rate or level | Avoidance of the depletion of natural resources in order to maintain an ecological balance”

Oxford Dictionary

To understand the sustainability of plywood wood, we assess the life-cycle of plywood furniture and household items. This life-cycle assessment (LCA) is a method to evaluate the environmental impacts of each stage in a product’s life-cycle, from the making to the recycling. Over the years, companies have strategically used LCA to research and create more sustainable products. 

In this article, we’ll use the cradle-to-grave perspective of the LCA, examining the five stages of the life-cycle of furniture and flooring made with plywood. However, you will also find some cradle-to-gate data where relevant. 

The life-cycle stages of plywood	Each stage’s sustainability
Sourcing of plywood components	Sourcing wood for plywood can be sustainable thanks to timber trees’ carbon sequestration and the high percentage of usable wood. On the other hand, glue raises environmental concerns as some commonly-used plywood adhesives contain toxic chemicals. However, natural-based bonding alternatives can be used to make plywood more environmentally friendly.
Manufacturing of plywood	Turning wood into plywood can have a significant carbon footprint due to the energy needed to run machinery. However, wood waste can be utilized as pellets to offset some of the emissions.
Transporting of plywood components	Transporting can be another carbon-intensive stage in the life-cycle of plywood furniture due to the emissions associated with operating the hauling vehicles that take timber to sawmills and factories, then plywood furniture to stores. Plywood made with locally grown woods would have a lower carbon footprint than plywood containing imported woods, providing they are both sold in the US.
Usage of plywood	Using plywood furniture can be sustainable thanks to the carbon capture during the products’ long life.
End-of-life of plywood	The end-of-life stage for plywood furniture and household items is not as sustainable as natural wood because plywood is non-biodegradable. However, plywood can be recycled, which is the most sustainable scenario for its end-of-life stage.

We’ll say that it is possible to find sustainable plywood for your floor or furniture. However, the actual environmental impact of a particular product depends on many factors. These include the type of wood, the nature of glue as well as the distance and mode of transportation. Let’s dive deeper into each stage and find out how it can be more sustainable. 

How Sustainable Is the Sourcing Plywood Components

Sourcing wood for plywood can be sustainable thanks to timber trees’ carbon sequestration and the high percentage of usable wood. On the other hand, glue raises environmental concerns as some commonly-used plywood adhesives contain toxic chemicals. However, natural-based bonding alternatives can be used to make plywood more environmentally friendly. 

What Is Plywood Made Of And What Does This Mean for Sustainability

The components for plywood are wood and glue. We will look at each of these for their sustainability. 

How Sustainable Is the Wood Used for Plywood

Plywood can be made using either softwood or hardwood. Some of the most popular wood used to make plywood are: 

• Cedar
• Pine 
• Douglas Fir 
• Birch
• Beech
• Oak (red oak and white oak) 

Generally, softwood tree species are fast growers. They regenerate quickly and supply plenty of wood. Conversely, hardwood trees tend to grow slowly. It takes a long time to replace a hardwood tree cut for timber. Thus, softwood plywood often is considered more sustainable, especially if compared with plywood containing rare tropical hardwoods. 

This rule can only be used as a starting point to guide you in sourcing plywood. It is important to note that the speed of growth varies significantly between the two groups of trees (hardwood vs. softwood trees) and within each group. 

On top of growing speed, the sustainability of sourcing a certain wood also depends on the timber trees’ population and lifespan. Aspen wood (a hardwood) can be more sustainable than redwood (a softwood) as the former might come from short-lived trees that are highly abundant. On the other hand, a redwood log could be cut from century-old trees – homes to many wild animals and insects. 

Logging has lesser consequences for the populations of some tree species in the temperate forests, such as aspen, willow, or pine because they are fast-growers and found in abundance. Conversely, slow-growing tropical hardwood trees like teak, rosewood, ipe, or batu (a subgroup of meranti) suffer greatly from logging. 

How Sustainable Are the Glues Used for Plywood

This necessary bonding component in plywood is not the most environmentally friendly material. However, some glues are better for human health and the earth than others. 

Where the environment is concerned, plywood glues can be divided into one category that contains formaldehyde (a potentially harmful gas) and one that does not. 

When a product contains added formaldehyde, the gas might be released into the air over a period of time. This process is called “off-gassing,” and a high-level exposure can cause skin rashes, shortness of breath, wheezing, and changes in lung function. 

Not all glues containing formaldehyde have the same level of off-gassing in terms of quantity and duration. 

• For example, Phenol-Formaldehyde (PH) (or phenolic glue) has a much lower emission than Urea-Formaldehyde glue.

• Phenolic glue, which is often used in plywood for outdoor purposes, is more likely to stop emitting gas after a short time.
• On the other hand, Urea-Formaldehyde glue keeps emitting gas for a longer time. (This is a common glue for interior-use plywood.)

Though formaldehyde at a high level is toxic, the off-gas released from glue is often very small once the glue is set and cured. Plywood with added formaldehyde is safe to use once it has time to air out and/or sealed (with an appropriate coating).

There are natural-based glues that don’t contain formaldehyde. They use some forms of soy proteins instead, which are less harmful to human health. However, all current soy-based adhesives are not 100% natural. They still use some chemicals to provide a firm binding. Thus, they are still not biodegradable. 

Where Are Plywood Components Usually Sourced From

The wood used to make plywood is most likely to come from cutting down trees (with cork as an exception where it is possible to harvest the outer bark for wood having to cut down the tree).

Harvesting wood from natural forests, especially when done illegally or unsustainably, can result in biodiversity loss regarding the tree species and wild animals that feed and shelter in the woods. 

One example is when loggers only cut down the biggest and tallest trees. That pattern would cause a reduction in the genetic diversity and quality of the trees within the stand, leading to gradual degradation of tree quality. 

Cutting down trees also disrupts the forests’ wild animals, which depend on the forest for food and shelter. 

In this aspect, wood from short-lived trees is generally more sustainable because long-lived trees support more wildlife.

An oak tree, for example, arguably supports more wildlife than any other tree species in Northern America. (A white oak tree can live up to 600 years and a red oak tree 500 years.) 

Some softwood species in the redwood and the pine family are among the oldest living tree species on earth.

The ecological impact of logging varies depending on a tree’s native forests and the forestry management practices.

The more biodiverse the forests, such as tropical rainforests in South America or Southeast Asia, the higher the cost of biodiversity loss. These bio hotspots also face rampant illegal logging and unsustainable logging, often due to lax management, to make matters worse.  

Here is the list of woods from tropical forests, some of which are the world’s richest in biodiversity. You need to purchase these woods with caution, whether it is in the form of natural wood or engineered plywood:

• Mahogany 
• Ipe 
• Cumaru 
• Tigerwood 
• Rosewood 
• Meranti
• Cocobolo
• Ebony 
• Merbau 
• Wenge 
• Teak

We have covered each of these woods in detail, so you can head over there and check out their sustainability, pitfalls, and tips to find the most environmentally friendly options. 

The rule of thumb for you as a consumer to tackle problems caused by illegal logging is to source sustainable woods. We will point you in the right direction with plywood at the end of this article. 

In total, logging of forestry products from plantations accounts for 26% of forest loss, a combination of deforestation and forest degradation. However, in tropical climates, the loss in bio-diverse forests is more significant (and sometimes less properly recorded) than that in temperate, well-managed logging forests. 

How Sustainable Can Plywood Be Sourced

Wood is generally considered a sustainable material because it is renewable. The growing and regrowing of wood also help mitigate the climate crisis through the process of carbon sequestration. 

As a tree grows, it absorbs CO₂ from the atmosphere while releasing oxygen. The tree acts as a carbon sink during its lifespan. The longer the lifespan, the more carbon a tree uptakes and keeps out of the atmosphere. 

Being a carbon sink means that they are taking greenhouse gasses out of the atmosphere, helping to mitigate the climate crisis. Carbon is then stored in branches, the trunk, and the root system. The bigger and taller a tree gets, the more it can hold. 

Thanks to the carbon sequestration and the fact that plywood is made mostly with wood, the carbon footprint of plywood can be negative. Generally, the forestation (growing) stage can uptake more carbon than the amount released during the transportation and processing of both wood and glue. 

For example, a life-cycle assessment of Sengon plywood found that 641 kg of atmospheric CO₂ was stored in 1m³ Sengon plywood. Additionally, up to 463 kilograms of biogenic carbon per m³ are fixed in the soil and in the intermediate plantations. The uptake total is much higher than the fossil CO₂ emissions (around 577 kilograms per 1m³) throughout the entire life cycle. 

 How Sustainable Is the Manufacturing of Plywood

Turning wood into plywood can have a significant carbon footprint due to the energy needed to run machinery. However, wood waste can be utilized as pellets to offset some of the emissions. 

The process of making plywood typically follows these seven steps: 

1. Cut down trees and saw the logs into manageable blocks, often 6.5 to 10 feet (2m to 3m) in length. 
2. Heat and soak the blocks of wood to soften them 
3. Cut these blocks into sheets (or veneer) to the required sizes 
4. Dry the ply sheets 
5. Glue three or five sheets together in layers that are rotated at 90o to the layer underneath
6. Hotpress the sheets to cure the adhesive 
7. Trim to the final size 

Cutting logs into sheets for plywood generally uses up more usable wood (up to 75%) than sawing logs into pieces for furniture or flooring. The standard conversion efficiency for American hardwood is 50%, which means 2 m³ of logs is harvested to produce 1 m³ of lumber. 

During these manufacturing steps, electricity might be needed for:

• Running sawing machines 
• Heating the wood 
• Drying sheets of wood 
• Hot-pressing 

If electricity comes from burning fossil fuels, it adds to the total carbon emissions. However, burning wood waste (biomass) generates energy that helps reduce the reliance on fossil fuels to run the drying kiln. For example, at least 90% of all thermal energy used for kiln drying in the US hardwood sector comes from biomass (instead of fossil fuels). 

Making glues has its own carbon emissions. Besides, some adhesives contain chemicals that emit Volatile Organic Compounds (VOC). 

Because of the energy required, manufacturing accounts for a large percentage of plywood’s total carbon footprint. For example, a life-cycle assessment of Sengon plywood found manufacturing accounts for 71% of CO₂ emissions generated for Sengon plywood sourced and sold locally (in Indonesia). 

How Sustainable Is the Transportation of Plywood Components

Transporting can be another carbon-intensive stage in the life-cycle of plywood furniture due to the emissions associated with operating the hauling vehicles that take timber to sawmills and factories, then plywood furniture to stores. 

Plywood made with locally grown woods would have a lower carbon footprint than plywood containing imported woods, providing they are both sold in the US. 

Here is a list of popular woods that can be hauled from the US forests:

Hardwoods	Softwoods
Aspen	Cedar
Beech	Douglas fir
Birch	Pine
Cherry	Spruce
Cottonwood	Redwood
Elm
Hickory
Maple (soft and hard)
Oak (white and red)
American Tulipwood
Walnut
Willow

Because of their various weights, some American woods have a higher transporting carbon footprint than others. Check our articles for individual woods for the specifics. 

And here are examples of imported woods, which travel long distances to reach the US market: 

• Cocobolo
• Cumaru 
• Ebony 
• Ipe 
• Mahogany 
• Meranti
• Merbau 
• Teak
• Tigerwood 
• Rosewood 
• Wenge 

Calculations made by the Norwegian Forest and Landscape Institute showed that smaller wood hauling trucks emitted more CO₂ per transported cubic meters of timber: 1.25 times more than larger wood hauling trucks, 1.3 times more than sea vessels, and six times more than freight trains. Therefore, the sustainable transportation option would be rail or large trucks running on biofuel. You can check with your plywood suppliers how their products are transported and opt for the more sustainable option. 

How Sustainable Is the Usage of Plywood

Using plywood furniture can be sustainable thanks to the carbon capture during the products’ long life. 

Plywood’s unique cross-layered structure is engineered to increase the strength of the material. Pound for pound, plywood is stronger than steel in static bending strength. While some natural woods are not very strong or durable, the plywood version can last longer. There are plywood samples that last more than a century. 

Though plywood is not biodegradable, it can be recycled and keeps its role as carbon storage. The more durable the plywood, the longer it stores carbon. 

How Sustainable Is the End-of-Life of Plywood

The end-of-life stage for plywood furniture and household items is not as sustainable as natural wood because plywood is non-biodegradable. However, plywood can be recycled, which is the most sustainable scenario for its end-of-life stage. 

There are two scenarios for plywood products – furniture, flooring, and household items- at the end of their life:

1. They can end up in landfills and don’t decompose. In this case, it keeps its role as carbon storage.
   
2. Wood products can also be upcycled and reused, extending their role as carbon storage and reducing the fossil CO₂ emitted as much as four times when comparing, for example, a recovered hardwood flooring with a new one. New plywood products often travel much further to their markets, compared with recovered plywood products. The latter is typically made in urban centers and sold locally, which lowers the transportation environmental burdens.

It is possible to recycle plywood, but it requires the kind of facilities that are not always available at household recycling. Thus, a high percentage of plywood furniture ends up in landfills, which is the less environmentally friendly option for this stage. So make sure you arrange to check where you can recycle your plywood furniture. 

Plywood is unlike natural woods in the sense that natural wood can be burned for biomass energy displacing coal or natural gas in generating electricity. Conversely, burning plywood can release toxic gasses because of the chemical compounds in glues. No-added formaldehyde plywood might not release VOCs while being burned. However, this material still contains some form of chemicals and, therefore, is not biodegradable. 

How Can You Buy Plywood More Sustainably

As far as the wood component in plywood is concerned, relevant environmental and original certifications would help you to pick a sustainable option. Reliable certifications for sustainable woods are: 

• Forest Stewardship Council: 

An FSC certification ensures that the wood in your plywood comes from responsibly managed forests that provide environmental, social, and economic benefits.

There are three levels of FSC certifications for plywood:

• FSC 100% Plywood: Plywood with this label contains wood that is entirely recyclable and from FSC-certified and managed forests
• FSC MIX Plywood: Plywood with this label is the most commonly seen. It means there is non-FSC certified wood used in the plywood. However, the non-FSC-certified component is not to be logged illegally or from forests where genetically modified trees are planted. 
• FSC Recycled Plywood: Plywood with this label contains only reclaimed material 

Despite the restrictions on non-FSC certified wood in FSC MIX Plywood, verifying the source can be difficult. Go for the FSC 100% or FSC Recycled labels when in doubt. 

• Program for Endorsement of Forest Certification: 

PEFC’s approaches to sustainable forest management are in line with protecting the forests globally and locally and making the certificate work for everyone. Getting a PEFC certification is strict enough to ensure the sustainable management of a forest is socially just, ecologically sound, and economically viable but attainable not only by big but small forest owners. 

Regarding glues, there are more environmentally friendly options that you can choose. Whenever possible, go for plywood that is made with formaldehyde-free adhesive. This will lower the toxicity and volatile organic compound emissions into the environment.

Similarly, if you are to seal your plywood (to lower the risk of VOC emissions), pick the most environmentally friendly options available. 

Why Is It Important to Buy More Sustainable Wood

Buying sustainable wood also means helping to prevent illegal or unsustainable logging, which harms the forests’ biosystems and accelerates climate change. 

Logging of forestry products from plantations accounts for 26% of forest loss. Cutting down trees for wood has a lesser impact on carbon storage than digging up the whole forest floor and turning it into farms or mines. However, if logging is not sustainably managed, it can badly damage wildlife.

When logging happens in tropical forests – the bio hotspots of our planet – the biodiversity loss can be much more damaging. Subtropical and tropical forests are packed with unique wildlife – endemic mammals, birds, and amphibians. The displacement of such wildlife during poorly managed logging would be a major contributor to global biodiversity loss. 

Sustainable management of forests also means that trees are cut down for timber only when they are mature. These trees will then be able to regrow and eventually replace the loss of canopy, absorb carbon from the atmosphere and reduce the effect of climate change. 

Final Thoughts

You can buy plywood as an alternative to natural wood as it would help reduce wood waste. However, you need to ensure that the wood used in plywood is from sustainably managed forests. Also, opt for the plywood option with no-added formaldehyde to reduce toxic gasses in the environment. Most importantly, use plywood furniture for as long as possible, upcycle the material to extend its usage, and arrange for it to be recycled fully.

Stay impactful,

Sources

• Science Direct: Life-cycle assessment (LCA)
• MIT SMR: Strategic Sustainability Uses of Life-Cycle Analysis
• European Environment Agency: cradle-to-grave
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• Impactful Ninja: How Sustainable Is Birch Wood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Beech Wood? Here Are the Facts
• Impactful Ninja: How Sustainable Is White Oak Wood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Red Oak Wood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Aspen Wood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Willow Wood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Teak Wood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Rosewood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Ipe Wood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Batu Wood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Meranti Wood? Here Are the Facts
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• Impactful Ninja: How Sustainable Is Mahogany Wood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Cumaru Wood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Tigerwood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Cocobolo Wood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Ebony Wood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Merbau Wood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Wenge Wood? Here Are the Facts
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• Impactful Ninja: How Sustainable Is Hickory Wood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Maple Wood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Tulipwood? Here Are the Facts
• Impactful Ninja: How Sustainable Is Walnut Wood? Here Are the Facts
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